Williams Jeffrey Credit - www.spacefacts.de

Personal: Male, Married, Two children. Born in Superior, Wisconsin, USA. US Army US Army

Astronaut Career

Astronaut Group: NASA Group 16 - 1996. Active Entered space service: 1 May 1996. Number of Flights: 2.00. Total Time: 192.79 days. Number of EVAs: 3.00. Total EVA Time: 0.82 days.

NAME: Jeffrey N. Williams (Lieutenant Colonel, USA)

NASA Astronaut Candidate (Mission Specialist)

PERSONAL DATA:

Born, January 18, 1958 in Superior, Wisconsin, but considers Winter, Wisconsin to be his hometown. Married to the former Anna-Marie Moore of Newburgh, New York. They have two children. Enjoys running, fishing, camping, skiing, scuba diving and woodworking. As a cadet at the U.S. Military Academy competed on the West Point sport parachute team and also held ratings of sport parachute jumpmaster and instructor. His parents, Lloyd D. and Eunice A. Williams, reside in Winter, Wisconsin. Her mother, Gloria M. Moore, resides in Modena, New York. Her father, S. Stevens Moore, is deceased.

EDUCATION:

Graduated from Winter High School, Winter, Wisconsin, in 1976; received a bachelor of science degree in applied science and engineering from the U.S. Military Academy in 1980, a master of science degree in aeronautical engineering and the degree of aeronautical engineer from the U.S. Naval Postgraduate School, both in 1987, and a master of arts degree in National security and strategic studies from the U.S. Naval War College in 1996.

ORGANIZATIONS:

Society of Experimental Test Pilots, American Helicopter Society, Army Aviation Association of America, Order of Daedalians, Officer Christian Fellowship.

SPECIAL HONORS:

Distinguished graduate of U.S. Naval Test Pilot School class 103; 1988 Admiral William Adger Moffett Award for Excellence in Aeronautical Engineering, Naval Postgraduate School; 1985 Daedalian Foundation Fellowship Award for Graduate Study in Aeronautics. Awarded 2 Meritorious Service Medals, the Army Commendation Medal, and various other service awards. Master Army Aviator and Parachutist badges.

EXPERIENCE:

Williams received his commission as a second lieutenant from the U.S. Military Academy in May 1980 and was designated an Army aviator in September 1981. He then completed a three-year assignment in Germany where he served as an Aeroscout Platoon Leader and Operations Officer in the 3rd Armored Division's aviation battalion. Following his return to the United States, Williams completed a graduate program in aeronautical engineering, and was subsequently selected for an Army assignment at the Johnson Space Center, where he served for over 4 years. In 1992, Williams was selected for the Naval Test Pilot School. After graduation in June 1993, he served as an experimental test pilot and Flight Test Division Chief in the Army's Airworthiness Qualification Test Directorate at Edwards Air Force Base, California. In 1995, he was selected for attendance at the Naval War College command and staff course as an Army exchange officer.

Williams has logged approximately 2,000 hours in more than 50 different aircraft.

NASA EXPERIENCE:

Williams was selected for an Army assignment at Johnson Space Center in 1987. Until his transfer in 1992, he served as a Shuttle launch and landing operations engineer, a pilot in the Shuttle Avionics Integration Laboratory, and chief of the Operations Development Office, Flight Crew Operations Directorate. Selected by NASA in May 1996, Williams again reported to Johnson Space Center in August 1996, to begin two years of training and evaluation. Successful completion of this initial training will qualify him for various technical assignments leading to selection as a mission specialist on a Space Shuttle flight crew.

• 19 May 2000 Flight: STS-101. Flight Up: STS-101. Flight Back: STS-101. Flight Time: 9.84 days.

• 30 March 2006 Flight: ISS EO-13. Flight Up: Soyuz TMA-8. Flight Back: Soyuz TMA-8. Flight Time: 182.95 days.

24 February 2000 - ISS Status Report: ISS 00-08. The International Space Station continues to orbit quietly without any significant problems hampering its operation as it awaits the arrival of a Space Shuttle crew to perform maintenance tasks while delivering logistics and supplies for use by future astronaut crews.

The next Shuttle crew to visit the ISS was finalized last week and includes Jim Voss, Susan Helms and Yuri Usachev - the second crew that will live aboard the ISS next year. They now will take an early 'peak' at their home during the STS-101 mission that will be commanded by Jim Halsell and piloted by Scott Horowitz. Rounding out the crew will be Mission Specialists Mary Ellen Weber and Jeff Williams. Atlantis is being readied at the Kennedy Space Center in Florida for the launch scheduled for no earlier than April 13.

While vehicle processing continues, mission planners are working on stowage and maintenance tasks that will be carried out on the 11-day flight. A spacewalk by Williams and Voss will include checking the position of a small crane mounted outside Zarya in addition to other tasks. The crane was installed during a spacewalk on the most recent Shuttle visit to the ISS. Plans call for Williams and Voss to ensure the crane is properly secured in its mounting socket.

Meanwhile, battery cycling continues on orbit with two of the six batteries currently in restoration mode, which is a procedure periodically carried out to maintain the life and capacity of each unit. At present, three batteries are supplying all the electrical needs of Station equipment.

STS-101 is designed to not only supply the Station with more logistics for use by future crews, but also to replace some of Zarya's aging batteries and other equipment in preparation for the arrival of the Zvezda service module in July. Presently, Zvezda is being readied for a launch between July 8-14.

Station managers plan to hold a meeting with the International Partners in the next week or two to finalize updates to the assembly sequence that will include launch target dates for the remainder of this year. That schedule will include Russian supply launches using the Progress resupply vehicles in addition to Shuttle logistics and assembly missions.

The first shuttle flight after the arrival of the Zvezda was approved to take place within a month after the service module's arrival. That STS-106 crew will be commanded by Terry Wilcutt with Scott Altman serving as pilot. Mission specialists include Dan Burbank, Rick Mastracchio, Ed Lu, Yuri Malenchenko, and Boris Morukov.

The International Space Station is in an orbit of 237 by 226 statute miles. Since the launch of Zarya in 1998, the ISS has completed more than 7,227 orbits. S

While it has been determined that the crane cannot float out of its housing, and thus does not pose a safety issue to the ISS, the desire is to attempt to seat the crane properly in its housing, called a worksite interface. During the next visit of a shuttle crew to the ISS, astronauts Jim Voss and Jeff Williams will reseat the crane in its housing before moving on to other tasks.

Battery cycling on Zarya continues with power levels well within workable ranges. Currently, the Unity module power levels are 430 watts.

Meanwhile, Atlantis is nearing completion of processing for its first flight in a year and a half after undergoing significant upgrades. The orbiter's payload bay doors are scheduled to be closed Monday with rollover to the Vehicle Assembly Building set for March 13. Launch remains targeted for no earlier than April 13.

While vehicle processing continues, mission planners continue to work timelines for the crew that will perform stowage and maintenance tasks that will be carried out during the flight.

The International Space Station is in an orbit of 235 by 226 statute miles. Since the launch of Zarya in 1998, the ISS has completed more than 7,320 orbits.

Atlantis' STS-101 mission not only provides an early look by three of its crew members at their future home, but also sets the stage for the arrival of the Zvezda service module set to launch on a Russian Proton rocket in mid July from the Baikonur Cosmodrome in Kazakhstan. Susan Helms, Jim Voss and cosmonaut Yuri Usachev will oversee maintenance tasks to restore the Zarya module's electrical power system to full capacity.

The three crew members were added to this mission for their unique abilities to step in on short notice to accomplish tasks for which they have already been training as the second crew to live alone next year on the ISS. Voss will join fellow crew member Jeff Williams in a space walk to replace a malfunctioning antenna on the Unity module and deliver additional components of a Russian crane to the outside of the station. The two astronauts also will check the current location of a small U.S. crane to ensure it is seated properly in its housing.

On orbit, the two components making up the International Space Station continue to operate in good health with electrical power management serving as the primary focus of flight controller attention. Zarya's automatic docking system that will be used to rendezvous and dock with Zvezda has been verified to be in good working condition following several tests over the course of the last few months. Kurs, as it's called, has two redundant systems and plans are being finalized as to which will serve as primary for the rendezvous and docking phase. Specific procedures are being developed as to the management of the station's power and communications systems during the final stages of the docking activities.

Earlier today in the California desert, an experimental spacecraft that is being considered for use as an emergency crew return vehicle from the ISS was tested for the fourth time. The X-38 was dropped from the wing of NASA's B-52 and touched down under the shadow of a huge parafoil. The next test of the craft at NASA's Dryden Flight Research Center is scheduled this summer.

The ISS continues to operate with no major systems failures as it circles the Earth every 92 minutes in an orbit of 232 by 217 miles. The station has completed more than 7,760 orbits since Zarya was launched in November 1998.

Launch is set to occur at about 4:15 p.m. Eastern time to perform life-extension maintenance tasks on the Zarya module, and to deliver supplies to the inside and outside of the Station for use by future crews.

Commander Jim Halsell has resumed full training activities after spraining his ankle a couple weeks ago and practiced landings in the Shuttle Training Aircraft last night. Joining Halsell on the mission are Pilot Scott Horowitz and Mission Specialists Mary Ellen Weber, Jeff Williams, Jim Voss, Susan Helms and Yuri Usachev. The latter three will focus their attention during the docked phase of the flight on repairing some equipment inside their future home.

Awaiting Atlantis' arrival, the International Space Station continues to operate with no major systems problems. Its electrical power system is being strategically managed to maximize the power required by operating systems inside the Zarya and Unity modules.

Meanwhile, in Moscow, the second and third stage engines have been delivered for final inspection and installation into the Proton rocket that will carry the next component of the ISS - the Zvezda service module - to orbit. Zvezda's launch remains slated between July 8 and 14 from the Baikonur Cosmodrome in Kazakhstan.

The current orbit of the ISS is 232 by 215 miles. The average decay of the Station's orbit is about 1-1 ½ miles per week. The altitude can be raised by using Zarya's thrusters, but will be unnecessary if Atlantis arrives later this month since the orbiter will perform an altitude reboost of the ISS before departing near the end of the flight. The ISS now has completed more than 7,860 orbits since Zarya was launched in November 1998.

Workers at the Kennedy Space Center in Florida have completed a swap-out of the power drive unit on the orbiter and will spend the next few days completing retests to verify the borrowed unit from Columbia is in good working order. At present there is no anticipated schedule impact to the April 24 launch.

Meanwhile, halfway around the world in Russia and Kazakhstan, work continues in preparation for Zvezda's launch atop a Proton launch vehicle. The Proton that will carry Zvezda into space currently is being assembled at its manufacturing plant at the Krunichev Space Center in Moscow. Its assembly is scheduled to be completed in mid May with delivery to the Baikonur Cosmodrome scheduled about two weeks later.

Awaiting the Proton's arrival at the launch site is the Zvezda service module, which will house life support systems, serve as the living quarters, and provide the ISS with command and control and reboost capability through the early assembly sequence. Zvezda's launch remains targeted to occur between July 8 and 14.

STS-101 will be commanded by Jim Halsell and piloted by Scott Horowitz. Joining them are Mission Specialists Mary Ellen Weber, Jeff Williams, Jim Voss, Susan Helms and Yuri Usachev. The seven-member crew will undergo their final physicals and wrap up training activities at the Johnson Space Center, Houston, this week prior to entering quarantine on Monday. The crew will fly to Florida next Friday, April 21, for the final three days of preparations prior to launch.

The current orbit of the ISS is 231 by 214 miles (372 x 344 kilometers). The average decay of the Station's orbit is about 1-1½ miles per week. While docked, Atlantis' reaction control system thrusters will be used to raise the orbit of the station by as much as 19 miles (about 30 kilometers). The actual orbit raising distance is calculated to 'place' the ISS at an altitude conducive to the rendezvous with Zvezda in late July. As of midday today, the station has circled the Earth more than 7,970 times since November 1998.

Final processing of the Shuttle is underway with the seven-member scheduled to arrive in Florida tomorrow at 3 p.m. East Coast time. Their arrival will be shown live on NASA Television.

The countdown begins tomorrow at 7 p.m. EDT leading toward a launch at the opening of a five-minute window at 4:15 p.m. Eastern.

Meanwhile, the on orbit Station is completing the final battery cycling of its four usable systems and will be in a good configuration for docking by the Shuttle next Wednesday. All systems are in good shape to support the rendezvous, docking and maintenance work scheduled throughout the STS-101 mission.

In addition to completing battery cycling, controllers will warm up the Unity module's shell so that it will be at the proper temperature when the Shuttle arrives. That activity should be completed before Monday's Shuttle launch.

At the Baikonur Cosmodrome in Kazakhstan, workers have completed electrical testing of the Zvezda service module, which is the next component of the ISS. Zvezda will be launched atop a Proton rocket in mid July. The ISS will dock with Zvezda about two weeks later near the end of July.

STS-101 will be commanded by Jim Halsell. Joining him on the crew are Pilot Scott Horowitz and Mission Specialists Mary Ellen Weber, Jeff Williams, Jim Voss, Susan Helms and Yuri Usachev.

The current orbit of the ISS is 229 by 213 miles (368 x 342 kilometers). The average decay of the Station's orbit is about 1-1½ miles per week. While docked, Atlantis' reaction control system thrusters will be used to raise the orbit of the Station by as much as 19 miles (about 30 kilometers). The actual orbit raising distance is calculated to position the ISS at the desired rendezvous altitude with Zvezda. As of midday today, the Station has circled the Earth more than 8,095 times since November 1998.

On May 22 mission specialists Jeff Williams and James carried out external maintenance work on the ISS.

On May 23 at 00:03 GMT the Atlantis crew opened the first hatch to PMA-2 and entered the Station. The crew replaced a set of batteries in Zarya, installed fans and ducting to improve airflow, and delivered supplies and equipment. Three hour-long orbit raising burns on May 24 and 25 by the RCS engines on Atlantis raised the station to a 372 x 380 km x 51.6 deg orbit.

The STS-101 crew left the station on May 26, closing the PMA-2 hatch at 08:08 GMT and undocking at 23:03 GMT. Atlantis performed a 180 degree flyaround of the station and departed the vicinity around 23:44 GMT.

Atlantis closed its payload bay doors around 02:30 GMT on May 29 and fired the OMS engines for deorbit at 05:12 GMT. The vehicle landed on RW15 at Kennedy Space Center at 06:20 GMT. Atlantis was to be turned around for the next ISS shuttle flight, STS-106.

Left in orbit was the renovated International Space Station, equipped with an upgraded electrical system, new fans, filters, fire extinguishers, smoke detectors and communications gear.

Riding aboard the upgraded and refurbished space Shuttle Atlantis, Commander Jim Halsell, Pilot Scott Horowitz and Mission Specialists Mary Ellen Weber, Jeff Williams, Jim Voss, Susan Helms and Yury Usachev rocketed away from their Florida launch site at 5:11 a.m. Central time, a pre-dawn launch by Shuttle standards. Atlantis quickly rose into daylight as it raced up the Eastern seaboard in pursuit of the 76-foot long, 35-ton international station, which was flying over the Ukraine, southwest of Kiev.

The launch was Atlantis' first since September 1997. Atlantis recently underwent major modifications, including the introduction of a state-of-the-art, hi-tech glass cockpit filled with computer displays to replace the old cockpit dials and switches.

Atlantis launched on time after three delays last month caused by high winds at the launch site and at overseas emergency landing strips. Today, conditions were perfect. Atlantis is scheduled to link up to the space station at 11:31 p.m. Central time Saturday night (12:31 a.m. Eastern time Sunday morning).

Once on orbit, Atlantis' crew began to set up shuttle systems for the planned 10-day mission, preparing to open the ship's cargo bay doors, which will be followed by the activation of the double Spacehab module housed in the rear of the cargo bay, containing more than a ton of supplies the crew will transfer to the station.

The astronauts will begin their first eight-hour sleep period just five hours after liftoff, at 10:11 a.m. Central time, and will be awakened at 6:11 p.m. this evening to begin their first full day in orbit. Prior to the start of that sleep period, Halsell and Horowitz will fire Atlantis' maneuvering jets in the first of a series of maneuvers designed to put the shuttle on a precise course to the International Space Station.

After the first rendezvous maneuver, Atlantis will be circling the Earth in a slightly elliptical orbit of about 201 by 124 statute miles, inclined 51.6 degrees to either side of the equator.

Commander Jim Halsell, Pilot Scott Horowitz and Mission Specialists Mary Ellen Weber, Jeff Williams, Jim Voss, Susan Helms and Yury Usachev will spend much of the day checking out orbiter systems and space walking equipment, while continuing to slowly close in on the station through a series of calculated rendezvous maneuvers.

The crew will examine and prepare the tools required to support rendezvous and docking operations as well as perform checks of the extravehicular mobility units, or space suits, that will be used by Williams and Voss during the planned space walk Sunday night into Monday morning. Both suits are checked far enough ahead of the space walk to ensure good working condition in plenty of time to allow for any required troubleshooting work by the specialists on the ground.

Also tonight and into tomorrow, Halsell will assist Weber in testing Atlantis' mechanical arm, checking its operation while conducting a video survey of the payload bay. This procedure will make certain the arm is functioning properly to support the space walk

Atlantis is currently in a highly elliptical orbit of 199 x 98 statute miles. At about 7 o'clock this evening, Central time, the shuttle was a little over 2,700 s.m. behind the station, closing in at a rate of about 546 s.m. every 90 minutes.

As of about 6:30 p.m. this evening, the Shuttle trailed the station by about 70 nautical miles and was closing in by about 14 nautical miles with each orbit of Earth. The final phase of rendezvous will begin when Atlantis reaches a point about eight nautical miles directly behind the station and fires its engines in a terminal phase initiation burn at 8:39 p.m. Central.

The TI burn, as it is called, will put the Shuttle on a course directly toward the station during the next orbit of Earth. As Atlantis moves within about a half-mile of the station, Halsell will take over manual control of the Shuttle's approach, flying the Shuttle from controls in the aft cockpit. Atlantis will arrive at a point about 600 feet directly below the station about 10:09 p.m. Central, and Halsell then will begin a half-circle of the orbiting outpost. Atlantis will pass about 350 feet in front of the station and then move to a point about 250 feet directly above it about 10:34 p.m. Central.

Halsell will then begin to descend toward the station and, at about 10:38 p.m. Central, hold position at a point about 170 feet away. Halsell will maintain that distance for about 20 minutes to allow the station to move within range of Russian ground communications stations before continuing the approach. At 11:20 p.m., Halsell will hold position again briefly at a point about 30 feet from the station to ensure the Shuttle and station docking mechanisms are precisely aligned. Docking is expected about 11 minutes later with the Shuttle contacting the station at a slow rate of about a tenth of a foot per second.

During the rendezvous, Pilot Scott Horowitz will assist Halsell in controlling Atlantis' approach. Mission Specialists Susan Helms and Yury Usachev also will assist with the rendezvous and docking, with Mary Ellen Weber and Jeff Williams operating the Shuttle's docking mechanism.

After docking, a hatch leak check will be performed and the astronauts will review plans for Sunday night's scheduled space walk by Williams and Jim Voss. Atlantis' crew will not open the hatch to the Unity module and enter the station until Monday evening, 24 hours after the space walk is completed.

Atlantis' Commander Jim Halsell and Pilot Scott Horowitz tested the navigation equipment and flight controls they will use late tonight to rendezvous with and then dock to the station. They also fired Atlantis' engines periodically to adjust the rate at which the Shuttle is closing in on the station. Atlantis is 430 statute miles behind the station now, closing in 30 statute miles with each orbit of Earth. Atlantis will continue that closing rate throughout the day while the crew sleeps.

During an engine firing Friday evening using both large orbital maneuvering system (OMS) engines on Atlantis, flight controllers saw an indication that one of two propellant valves for the left OMS engine may have failed to close. The engine's backup valve did operate normally, and the engine remains in good operating condition. However, as a precaution, the left engine will not be used again until Atlantis is ready to deorbit at the completion of the flight. Controllers are continuing to analyze the information and are uncertain if the valve actually did not operate properly or whether the indication may have been an errant sensor reading. The right OMS engine alone can be used for large rendezvous engine firings with no impact on the mission.

Astronauts Jeff Williams and Jim Voss checked the spacesuits and equipment they will use during the upcoming spacewalk, finding them in good shape. Three suits -- one for Williams, one for Voss and a spare, which could be used by either -- were checked out aboard Atlantis. Williams and Voss were assisted in the checks by Horowitz, who will coordinate the spacewalk activities from within the cabin. Later, fellow crew member Mary Ellen Weber successfully tested the Shuttle's robotic arm. Weber will operate the arm during the spacewalk to maneuver Williams and Voss between Atlantis and the station. Weber uncradled the arm this morning and used it to survey the Shuttle's payload bay. Later, Weber powered on the docking system Atlantis will use to attach to the station and extended the system's docking ring. The ring latches onto the station when the Shuttle makes contact and is then retracted to secure the two spacecraft together.

The crew will begin a sleep period at 8:11 a.m. and awaken at 4:11 p.m.. At 8:39 p.m., with Atlantis trailing the International Space Station by about 50,000 feet, Halsell will fire the Shuttle's engines to initiate the final phase of the rendezvous. Just before 10 p.m., as Atlantis reaches a point about a half-mile below the station, Halsell will take over manual control of the approach. He will reach a distance of about 170 feet from the station at 10:39 p.m. Docking is expected at about 11:31 p.m. Atlantis is in an orbit with a high point of 204 miles and a low point of 199 miles, circling Earth every 90 minutes.

Halsell and his crew performed the rendezvous and docking with the station by the book, docking on target at 11:31 p.m. CDT Saturday. Although Atlantis is now firmly attached to the station, the astronauts will not enter the new outpost until Monday, turning their immediate attention instead to a six and half-hour spacewalk to begin late tonight.

Astronauts Jim Voss and Jeff Williams will perform tonight's spacewalk to install the final part of a Russian-built crane on the station's exterior; replace a faulty communications antenna; and install various cables and handrails. Following the docking, Voss and Williams spent several hours this morning preparing the tools and equipment they will use for the sojourn outside and double-checking the spacewalk plans with the rest of the crew.

The crew also lowered the air pressure inside Atlantis from the standard sea-level pressure of 14.7 pounds per square inch to 10.2 pounds per square inch, a pressure equivalent to that felt at an altitude of 10,000 feet on Earth. The lower cabin pressure helps Voss and Williams purge nitrogen from their bodies to avoid decompression sickness when they go to the 4.2 pounds per square inch, pure oxygen atmosphere of the spacesuits this evening.

The International Space Station remains in good condition, ready for the crew to enter on Monday to start several days of maintenance and unloading of supplies. As the crew's waking hours wound down early this morning, Mary Ellen Weber, who will oversee much of the transfer of equipment, and Halsell made some early preparations of the docking system for the eventual entry into the station.

The crew will begin a sleep period at 8:11 a.m. and awaken at 4:11 p.m. for a fourth day in space, a day devoted to the spacewalk. Voss and Williams are planned to begin donning their gear and suits at 6:11 p.m., leading to a predicted exit from Atlantis' airlock hatch at 9:31 p.m. During the spacewalk, Williams' suit will be distinguishable from Voss' suit by red stripes around the legs. The astronauts are scheduled to conclude the spacewalk at 4:01 a.m. Monday.

Atlantis is operating well with flight controllers reporting no problems of significance for any of the mission's activities. The shuttle and station are in an orbit with a high point of 209 statute miles and a low point of 203 statute miles, circling Earth every 91 minutes.

Mission Specialists Jeff Williams and Jim Voss will have several tasks as part of the planned six and a half hour extravehicular activity, or EVA, this evening. They will inspect and then secure a U.S.-built cargo crane known as the Orbital replacement unit Transfer Device that originally was installed during a space walk on the STS-96 mission in June 1999. Williams and Voss then will complete assembly of a Russian cargo crane called Strela (Russian for "arrow") that was begun on a space walk during STS-96. Strela will be placed on the Pressurized Mating Adapter-1 that connects the Unity node to the Zarya control module in the same vicinity as the American crane.

The two space walkers then will turn their attention to replacing one of Unity's two early communication antennas. That antenna has been experiencing some problems. Williams and Voss then will move on to their final EVA task with the installation of eight handrails on the station's exterior. This is part of some get ahead work for two upcoming assembly flights -- STS-92 in late September and STS-97 in January 2001. The STS-92 crew will install the Z-1 truss structure, and the STS-97 crew will deliver the U.S. Laboratory module. If all activities go as planned, the space walk should conclude about 3:45 a.m. CDT. Monday. During tonight's EVA activity, Williams will be identifiable by red stripes on the arms and legs of his spacesuit while Voss' spacesuit will be solid white. Tonight's EVA will mark the 85th space walk in U.S. history and the fifth dedicated to assembly of the International Space Station. To date, Shuttle astronauts have performed almost 300 hours of EVAs (297 hours, 53 minutes). The duration of the four previous station assembly space walks is 29 hours, 17 minutes.

Atlantis is operating well with flight controllers reporting no problems of significance for any of the mission's activities. The shuttle and station are docked in an orbit with a high point of 209 statute miles and a low point of 203 statute miles, circling Earth every 91 minutes.

Voss and Williams started the spacewalk early and remained ahead of schedule throughout. The astronauts secured a United States-built crane that was installed on the station last year; installed the final parts of a Russian-built crane on the station; replaced a faulty antenna for one of the station's communications systems; and installed several handrails and a camera cable on the station's exterior. The six-hour, 44-minute spacewalk began at 8:48 p.m. CDT Sunday and was completed at 3:32 a.m. CDT today. Assisting with the activities from inside Atlantis' cabin was Pilot Scott Horowitz while Mission Specialist Mary Ellen Weber operated the Shuttle's robotic arm, which she used to maneuver Voss during much of the spacewalk.

The extravehicular activity conducted by Voss and Williams marks the fifth spacewalk conducted for construction of the International Space Station; the 49th spacewalk based out of the Space Shuttle; and the 85th spacewalk in history conducted by U.S. astronauts.

The crew's attention now turns to entering the station, a process planned to begin at 7:11 p.m. today. The astronauts will open a total of six hatches as they move through the station's compartments. The first hatch into the station's Unity connecting module will be opened about 7:56 p.m. and the first hatch into the Zarya module will be opened about 9:11 p.m. Once inside the station, the crew will begin transferring equipment and performing maintenance work immediately. Replacement of four batteries in the Zarya will begin about 11:31 p.m., with astronaut Susan Helms and cosmonaut Yury Usachev scheduled to install two new batteries and their associated electronics. Helms and Usachev will install the remaining two replacement batteries later during the docked phase of the flight.

The crew plans to go to sleep at about 8 this morning and will be awakened by Mission Control at 3:56 p.m., with the focus of work this evening being the first entry into the station. Atlantis and the International Space Station remain in good condition orbiting Earth each 91 minutes with a high point of 209 statute miles and a low point of 203 statute miles.

Halsell along with Pilot Scott Horowitz and Mission Specialists Mary Ellen Weber, Jeff Williams, Susan Helms, Jim Voss and Yury Usachev will spend their second day inside the station as they continue the maintenance work and supply transfer activities that began yesterday. During their first day, Atlantis' crew moved 870 pounds of supplies and equipment inside the station. That material along with the 326 pounds of equipment attached to the exterior of the station by Williams and Voss during their space walk means almost 1,200 pounds of gear already have been transferred to the station. A total of 3,381 pounds of equipment and provisions will be transferred to the station before Atlantis undocks.

Maintenance work on Flight Day Six will include the third of four planned replacements of station batteries. Helms and Usachev will repeat the procedures they followed yesterday when the first two batteries were replaced. One of the batteries replaced yesterday already has been recharged and been pronounced in excellent condition. The second replacement battery will go through its charging and checkout shortly. All of the battery replacement work is carefully designed so that at least four batteries are always online and available to support station operations.

Other maintenance work on schedule today includes the installation of new smoke detectors, and replacement of fire extinguishers that are nearing the end of their design life.

The first of three planned station reboost maneuvers is scheduled to take place tonight at 7:01 p.m. CDT. The maneuver will see Atlantis' steering jets fire 27 times over a 58 minute period to boost the average altitude of the station by about nine statute miles. A similar process will be repeated tomorrow and again on Thursday to increase the station's average altitude by a total of about 27 statute miles before Atlantis departs. The higher altitude will aim the International Space Station toward the optimum orbit for a link up with the Russian Zvezda living quarters module planned for launch in July.

Late this evening, Halsell, Williams and Voss will take a few minutes to conduct a trio of interviews with reporters from the Cable News Network, Armed Forces Television and Space.Com. The interviews are scheduled to begin at 11:41 p.m. CDT.

The Atlantis and station complex continues to operate in fine fashion orbiting the Earth once every 91 minutes.

Halsell, Horowitz and Mission Specialists Mary Ellen Weber, Jeff Williams, Susan Helms, Jim Voss and Yury Usachev will spend their third day inside the station continuing the maintenance work and supply transfer activities that began Monday evening. During their first two days inside the station, the astronauts have moved more than a ton (2,049 pounds) of supplies and equipment inside the facility to be used by the first station crew. More than 3,000 pounds will be transferred to the station before Atlantis undocks on Friday evening.

Helms and Usachev already have completed the replacement of the fourth and final battery. The second battery replaced on Monday evening is fully recharged and working well as it supports station operations. The third battery, which was replaced last night, has begun its 20-hour charging process. All of the battery work is designed so that at least four of the station's six batteries are available to support station systems.

Other work on tap for this evening includes the replacement of a Zarya radio telemetry system which has reached the end of its design life. The radio telemetry system collects and stores station data when ground station communications are not available. The crew also will fill four large water bags and transfer the bags to the station to join seven similar bags left during the STS-96 mission last year. The water bags will be part of the potable water supply used by the first station crew when it arrives later this year.

Tonight also will see the second of three planned reboost maneuvers to raise the station's altitude. The one-hour procedure will involve 27 pulse firings of Atlantis's maneuvering thrusters. The three reboosts will raise the station to a new altitude about 237.5 x 227 statue miles and will place the station in the optimum altitude for the arrival of the Zvezda Service Module when it is launched in July.

Shuttle and station managers have decided to move the undocking time to one orbit later. The new undocking time is now 6:07 p.m. CDT on Friday, May 26th and will happen while the two spacecraft are over Russian ground stations. The later undocking will allow the crew to get a full eight-hour sleep period. Atlantis will make shortened fly around, one half revolution of the station, before leaving the vicinity of the station. The later undocking will have no impact to Atlantis' landing at Kennedy Space Center which still is planned for 1:18 a.m. CDT Monday, May 29th.

Later this evening at 10:11 p.m. CDT, Halsell, Horowitz and Helms will participate in a trio of interviews with the ABC Radio Network, KOIN-TV in Portland, Oregon, and a webcast education event for the Housing and Urban Development agency.

The Atlantis and station complex continues to operate well, completing one orbit of the Earth every 91 minutes.

Late Wednesday, Astronauts Susan Helms and Jim Voss along with Cosmonaut Yury Usachev completed the installation of a fourth and final fresh battery in the station. Station flight controllers in Russia have completed charging two of the newly installed batteries and they are operating perfectly. The third new battery is currently undergoing a 20-hour charging process, although controllers did note some apparently irregular readings in data during the early portions of the charging activity. However, after further analysis, controllers now believe the irregular information was likely a ground communications problem and that the battery is in excellent condition. Charging of the fourth new battery will begin later today and be completed before Atlantis undocks from the station on Friday.

Later, Voss and Williams installed several new storage compartments behind panels in the Zarya module. Helms and Usachev also installed a new Radio Telemetry System in the module, a memory unit that can store data onboard when the station is not in communications with the ground. The new memory unit replaces one that was nearing the end of its planned operational lifetime.

Commander Jim Halsell and Pilot Scott Horowitz fired Atlantis' steering jets to perform the second part of a three-day maneuver that is raising the station's orbit. Atlantis' jets were fired 27 times over the course of almost an hour to raise the Atlantis-station complex's average altitude by about nine miles. The third and final orbit-raising activity is planned tonight and will leave the station about 27 miles higher than when Atlantis arrived, in an optimum orbit to await the launch of a station living quarters module by Russia in July.

The crew has transferred more than a ton of gear -- ranging from sewing kits to clothing -- to the station to await use by the first resident crew. Among the items transferred this morning were a stationary bicycle ergometer as well as four 12-gallon bags of drinking water. Tonight, the crew will wrap up the transfer of equipment to the station with plans in place to unload a total of more than 3,000 pounds of gear by the time Atlantis leaves. Halsell, Horowitz and Mary Ellen Weber will take a brief break from their activities at 9:11 p.m. CDT for an interview by CBS News, Fox News and KTBS-TV of Shreveport, LA.

The crew will begin a sleep period at 7:11 a.m. CDT and awaken at 3:11 p.m. to begin the eighth day of the mission. Atlantis is scheduled to undock from the station at 6:07 p.m. CDT Friday and land at the Kennedy Space Center, Florida, at 1:18 a.m. CDT Monday.

The Atlantis-International Space Station complex is now in an orbit with an altitude of about 225 miles, circling Earth every 91 minutes.

The main task of the day will be completing the transfer of gear and supplies to the station. In the first three days of transfer activities, the crew has moved more than 3,000 pounds of material onto the station.

The third and final reboost maneuver began a few minutes ago at 6:36 p.m. CDT. Like the two previous reboosts, Atlantis' reaction control system jets will be fired 27 times over a 58 minute period to gently raise the station. At the end of tonight's reboost, it is expected that the station's average altitude will have been raised by 27 statue miles.

The astronauts have completed all battery work on the station. The third battery that was replaced has completed its recharging and testing and has been put back online supporting station operations. The fourth and final new battery will begin its recharge later this evening and will be back online before Atlantis undocks tomorrow evening.

Shortly before they begin exiting the station for the final time, Halsell, Horowitz and Weber will take a few minutes to conduct a trio of interviews with three news organizations -- CBS Newspath, Fox News Network and KTBS-TV in Shreveport, LA -- starting at 9:11 p.m. CDT.

Just before 11:30 p.m., Halsell and his crew will reverse the steps they used when they entered the station Monday evening, closing each of the five hatches associated with station components or transfer tunnels. The overall process of closing out the station and preparing for undocking is expected to take about two hours to complete.

Everything remains on schedule for undocking on Friday evening at 6:07 p.m. CDT. Atlantis will perform a one half revolution of the station, before the final separation burn is initiated. Atlantis remains on track for a landing back at Kennedy Space Center at 1:18 a.m. CDT on Monday, May 29th.

Undocking occurred at 6:03 p.m. Central time, as Pilot Scott Horowitz slowly backed Atlantis away from the space station and then flew a half-circle around the station, before firing Atlantis' jets in a final separation burn at 6:41 p.m. Atlantis' crew leaves behind a refurbished and rejuvenated space station with four new batteries, 10 new smoke detectors, and four new cooling fans in the Zarya module, a revamped communications system in the Unity module and 1 ½ tons of other supplies, including clothing and water.

Now flying solo, the seven-member Atlantis crew will enjoy several hours of off-duty time tonight in recognition of the ambitious pace of work they maintained throughout this flight. Commander Jim Halsell, Horowitz, and Mission Specialists Jeff Williams, Mary Ellen Weber, Jim Voss, Susan Helms and Yury Usachev will power down some of the equipment used during today's undocking and flyaround, and then will perform some routine housekeeping tasks before beginning their scheduled off duty time.

Toward the end of the crew's day, Usachev will take some time to talk with Russian media gathered at the Russian Mission Control Center just outside of Moscow in an event scheduled at 4:26 a.m. Central time Saturday morning. Usachev, along with crewmates Voss and Helms, will visit the station again next year to spend more than four months on board as the second resident crew scheduled to live on board.

The station is now in the optimum orbit to await the arrival of the next major station component -- a Russian-built living quarters that will launch in July -- flying in an orbit with a high point of 238 miles and a low point of 230 miles, circling the Earth every 92 minutes.

"I couldn't be happier with the way this mission has gone," Lead Flight Director Phil Engelauf said. "Our accomplishments are at more than 100 percent for the flight."

"The crew will be leaving a pristine International Space Station behind them," added Paul Hill, Lead Station Flight Director.

Highlights of the crew's work aboard the station included the installation of four new batteries and associated electronics; 10 new smoke detectors in the Zarya module; four new cooling fans; additional cables for the Zarya computer to enhance its capabilities; a new communications memory unit; and a new power distribution box for the United States-built backup communications system. A new communications antenna, the final parts of a Russian crane, and various cabling and handholds were installed on the station's exterior by Astronauts Jeff Williams and Jim Voss during a six-hour, 44-minute spacewalk. All of the new equipment has been checked out and is in excellent condition.

The crew unloaded over 3,300 pounds of gear from Atlantis. Subtracting equipment removed from the station and stowed on Atlantis, the net change in mass for the station is about one additional ton. Along with the new electrical equipment installed, the crew also stowed supplies for future crews aboard the station, including about 48 gallons of water in four 12-gallon bags; a treadmill, exercise bicycle ergometer, and resistive exercise device; and sewing kits, trash bags, clothes, tools, books, note pads and can openers, among other items. Overseeing the unloading and stowing of supplies was Astronaut Mary Ellen Weber. Also, Commander Jim Halsell and Pilot Scott Horowitz fired Atlantis' steering jets in gentle, hour-long maneuvers during each of the past three days to raise the station's orbital altitude by 27 miles. The station is now in the optimum orbit to await the arrival of the next major station component -- a Russian-built living quarters that will launch in July.

Astronaut Susan Helms and Cosmonaut Yury Usachev began backing out of the station -- closing five hatches behind them -- by closing a hatch to the Zarya module's main compartment at 12:23 a.m. CDT. The final hatch to the station was shut at 3:04 a.m. CDT as the orbiting complex flew about 234 miles above the Red Sea. Helms, Usachev and Voss will again visit the station next year to spend more than four months as the second crew to live aboard. In total, the astronauts on Atlantis spent three days, eight hours and one minute with the hatches open to the station during the mission.

Atlantis' undocking from the International Space Station is planned for 6:03 p.m. CDT, followed by a half-loop flyaround of the station - from above to underneath - before firing its jets for the final separation. Atlantis and the station are in an orbit with a high point of 238 miles and a low point of 230 miles, circling Earth every 92 minutes.

Shortly after 7 p.m. today, Commander Jim Halsell, Pilot Scott Horowitz and Flight Engineer Jeff Williams successfully test fired Atlantis' steering jets and verified the performance of the various aerosurfaces that will be used during Atlantis' high-speed return to Earth. This checkout of Atlantis' flight control surfaces and systems is a routine activity on the day prior to landing to verify that all required systems are operating as expected. The tests were monitored by Entry flight director John Shannon from Mission Control in Houston.

As Halsell, Horowitz and Williams conducted their work from the flight deck, crewmates Mary Ellen Weber, Jim Voss, Susan Helms and Yury Usachev continued stowing away equipment used over the past nine days on orbit. Throughout the five days of docked operations with the International Space Station, the Spacehab module in Atlantis' payload bay served as a way station for more than 3,000 pounds of material transferred between the two vehicles. As the astronauts prepare for their Memorial Day landing, they will ensure that equipment housed in that module -- and in Atlantis' crew cabin -- is properly stowed and secured in place.

Midway through the crew day -- about 11 p.m. -- the astronauts will gather for a final review of entry and landing procedures, and then will continue their stowage activities. Williams and Voss, who conducted a 6 1/2 hour space walk earlier in the mission, also will pack up and stow away their spacesuits and associated hardware.

The crew will take time from tonight's entry preparations to talk with reporters located at the Johnson Space Center in Texas, the Kennedy Space Center in Florida and the Russian Mission Control Center outside of Moscow in an interview scheduled to begin at 10:41 p.m.

Preliminary weather forecasts for Monday morning's landing indicate a slight possibility of rain within 30 miles of the landing site, and cross winds in excess of acceptable limits. The weather forecasts will be refined over the course of the next 24 hours in preparation for landing. For a 1:20 a.m. Central time landing at KSC, Atlantis' orbital maneuvering system engines would be fired in a deorbit burn at 12:13 a.m. In the event weather precludes a landing on the first opportunity, a second opportunity exists for a landing in Florida on the next orbit, with a deorbit burn at 1:50 a.m. resulting in a 2:56 a.m. landing.

Saturday evening, Commander Jim Halsell, Pilot Scott Horowitz and Flight Engineer Jeff Williams successfully test fired Atlantis' steering jets and verified the performance of the equipment Atlantis will use for its trip home, finding everything in good shape. Early Sunday, Halsell fired Atlantis steering jets to lower its orbit by about nine miles, a maneuver that optimizes the landing opportunities that will be available for the shuttle.

For a 1:20 a.m. Monday landing at KSC, Atlantis' orbital maneuvering system engines would be fired in a deorbit burn at 12:13 a.m. In the event weather precludes a landing on the first opportunity, a second opportunity exists for a landing in Florida on the next orbit, with a deorbit burn at 1:50 a.m. resulting in a 2:56 a.m. landing. The weather forecast for landing indicates acceptable conditions, although forecasters will be monitoring the progress of a front moving toward Florida throughout the day and its potential effect on winds at the Shuttle Landing Facility runway.

Two opportunities for a landing in Florida also are available on Tuesday and again on Wednesday, if needed. Also on Wednesday, Atlantis could land at Edwards Air Force Base, California, if required.

The crew sleep period begins at 7:11 a.m. and will end with a wake-up call from Mission Control at 3:11 p.m. Central. They will begin deorbit preparations in earnest just after 8 p.m. The shuttle's payload bay doors would be closed at about 9:30 p.m. and a go or no go decision would be made by Mission Control at about midnight in preparation for a 1:20 a.m. Monday landing.

Commander Jim Halsell flew Atlantis to a nighttime touchdown at the Florida spaceport at 1:20 a.m. Central time to complete a 4,076,000 mile mission, the second Shuttle flight of the year. It was the 14th nighttime landing in Shuttle history and the 22nd consecutive mission to end with a landing at KSC. Halsell was joined on Atlantis' flight deck by Pilot Scott Horowitz, Flight Engineer Jeff Williams and Mission Specialist Mary Ellen Weber. Crewmates Susan Helms, Jim Voss and Yury Usachev were seated down on the orbiter's middeck for entry and landing.

Atlantis returned to Earth after Flight Director John Shannon determined that crosswinds at the Kennedy Space Center's three-mile long landing strip were gentle and steady, enabling him to give the astronauts the green light to come home on time. Halsell fired the Shuttle's braking rockets at 12:12 a.m. Central time, allowing Atlantis to drop out of orbit for its high-speed descent. Atlantis passed over southern Mexico and the Gulf of Mexico before crossing over the Sarasota / Ft. Myers area of Florida en route to the Cape. Atlantis broke the quiet of the pre-dawn hours in Central Florida with a double sonic boom just minutes before touchdown, heralding its arrival at the landing site as it went subsonic.

Left in orbit is the renovated International Space Station, equipped with an upgraded electrical system, new fans, filters, fire extinguishers, smoke detectors and communications gear. ISS flight controllers report that the complex is functioning in excellent condition. The Station is orbiting at an altitude of about 238 statute miles, awaiting the arrival of its next component, the Russian Service Module "Zvezda", which is scheduled to be launched on a modified Proton rocket from the Baikonur Cosmodrome in Kazakhstan in July. The ISS will automatically rendezvous and dock with "Zvezda" about two weeks after the new module is placed in orbit.

Atlantis will now be processed for the next Shuttle flight in early September to return to the International Space Station with another crew for the outfitting and supply of the newly arrived Service Module. That flight, STS-106, will be led by veteran Commander Terry Wilcutt.

The STS-101 astronauts will spend Memorial Day relaxing with their families in Florida before returning to Houston Tuesday afternoon at around 1:30 p.m. Central time for a welcoming ceremony at Ellington Field near the Johnson Space Center. JSC employees and families are invited to attend the ceremony.

Filled with trash and items no longer needed, the Progress 19 vehicle undocked from the Zvezda living quarters module at 5:06 a.m. EST. Three hours later, Russian flight controllers commanded its engines to fire to put it on course to plunge into the atmosphere and burn up over the Pacific Ocean. The cargo ship was docked to the station since September 2005.

The station's Progress 20 cargo vessel, which arrived in December 2005, remains attached to the Pirs Docking Compartment.

Also this week, McArthur replaced the trace contaminant control system in the Destiny Laboratory. The system removes impurities from the cabin air. It experienced a slightly degraded performance over the past few months, but is operating normally.

On Monday, McArthur will attempt to reconnect and activate the major constituent analyzer in Destiny. It is a mass spectrometer that measures compounds in the station's atmosphere. Efforts to activate the system two weeks ago were unsuccessful due to what is believed to be damaged or bent electrical connectors.

Once the device is activated, plans can resume for a crew "campout" in the Quest Airlock to test streamlined spacewalk preparation procedures. The new procedures will shorten the time needed to cleanse nitrogen from spacewalkers' bodies to prevent decompression sickness. For the test, the crew will spend the night in Quest at a reduced pressure, lessening the time needed to breathe pure oxygen in advance of a spacewalk.

The "campout" technique will be used for the first time for spacewalks on the STS-115 shuttle mission later this year. If the major constituent analyzer is successfully activated, the campout test will be scheduled around March 23.

McArthur continued preparations for the arrival of the next shuttle mission. Discovery is targeted for launch no earlier than May on that flight, designated STS-121. This week, McArthur put unneeded items in racks earmarked for return to Earth aboard Discovery.

McArthur and Tokarev will soon begin preparations for a short trip from the station. Managers have agreed on a tentative schedule on March 20 for the crew to relocate their Soyuz TMA-7 spacecraft from the Earth-facing docking port of the Zarya module to the aft docking port of Zvezda. McArthur and Tokarev will undock from Zarya and conduct a 37-minute flight to re-dock at Zvezda. The move will clear the Zarya port for the April 1 arrival of the Soyuz carrying the next station crew, Expedition 13.

Expedition 13 is commanded by Pavel Vinogradov. Jeff Williams is NASA Flight Engineer. Brazilian astronaut Marcos Pontes will fly with them to the station for a short stay, returning to Earth a week later with McArthur and Tokarev.

Next week, McArthur will brush up on his robotics skills, operating the Canadarm2 for engineering tests. The arm also will be remotely commanded by flight controllers in Houston. They will operate the arm to survey one of two integrated umbilical assembly mechanisms on the mobile transporter rail car. The assembly's cutting blade system malfunctioned Dec. 16, severing one of two umbilicals on the transporter. The assembly will be replaced on the second of the three spacewalks planned for Discovery's mission. Controllers also will use the arm to survey a vent port for the carbon dioxide removal assembly on the Destiny Laboratory.

If all goes as planned, the flight will take less than 40 minutes. Undocking is scheduled for 1:49 a.m. EST; with docking scheduled for 2:23 a.m. EST.

This move will clear the Zarya port for the March 31 arrival of the Expedition 13 crew and a Brazilian Space Agency astronaut on another Soyuz vehicle.

Preparations included testing Soyuz systems and thrusters and reviewing trip procedures. On Sunday, the crew will configure station and Soyuz systems. The configuration is to ensure the station could operate without the crew onboard; in the unlikely event the Soyuz could not successfully re-dock.

This week, Expedition 13 Commander Pavel Vinogradov and Flight Engineer Jeff Williams completed final training at the Gagarin Cosmonaut Training Center in Star City, Russia.

The crew will travel Saturday to the Baikonur Cosmodrome in Kazakhstan for final launch preparations, along with Brazilian astronaut Marcos Pontes. Pontes will fly to the station with Expedition 13 on a 10-day mission, returning to Earth with Expedition 12. Launch is scheduled for March 29 at 9:30 p.m. EST.

NASA's payload operations team at the agency's Marshall Space Flight Center, Huntsville, Ala., worked with McArthur to test an experiment facility on the station. The thermal and pressure sensors inside the microgravity science glovebox are checked annually to keep it certified for experiments. McArthur completed inspection and cleaning of the facility.

McArthur also dedicated some of his free time last weekend to research work. On Saturday morning, he conducted an experiment that aims to improve future experiments that involve mixing fluids.

The cellular biotechnology operations support systems fluid dynamics investigation is a series of experiments to improve fluid mixing techniques and control bubble distribution for cell culture in orbit.

If all goes as planned, the flight will take less than 40 minutes. Undocking is scheduled for 12:49 a.m. CST with docking scheduled for 1:23 a.m. CST.

This move will clear the Zarya port for the March 31 arrival of the Expedition 13 crew and a Brazilian Space Agency astronaut on another Soyuz vehicle.

Preparations included testing Soyuz systems and thrusters and reviewing trip procedures. On Sunday, the crew will configure station and Soyuz systems. The configuration is to ensure the station could operate without the crew onboard; in the unlikely event the Soyuz could not successfully re-dock.

This week, Expedition 13 Commander Pavel Vinogradov and Flight Engineer Jeff Williams completed final training at the Gagarin Cosmonaut Training Center in Star City, Russia.

The crew will travel Saturday to the Baikonur Cosmodrome in Kazakhstan for final launch preparations, along with Brazilian astronaut Marcos Pontes. Pontes will fly to the station with Expedition 13 on a 10-day mission, returning to Earth with Expedition 12. Launch is scheduled for March 29 at 8:30 p.m. CST.

NASA's payload operations team at the agency's Marshall Space Flight Center, Huntsville, Ala., worked with McArthur to test an experiment facility on the station. The thermal and pressure sensors inside the microgravity science glovebox are checked annually to keep it certified for experiments. McArthur completed inspection and cleaning of the facility.

McArthur also dedicated some of his free time last weekend to research work. On Saturday morning, he conducted an experiment that aims to improve future experiments that involve mixing fluids.

The cellular biotechnology operations support systems fluid dynamics investigation is a series of experiments to improve fluid mixing techniques and control bubble distribution for cell culture in orbit.

Soyuz Commander Valery Tokarev and Expedition 12 Commander Bill McArthur moved their Soyuz spacecraft from the Zarya module to the Zvezda living quarters module early Monday. They will use the same vehicle to return to Earth April 8. This week's move opened the Zarya docking port for the arrival of the Expedition 13 crew.

The Expedition 13 crew, Commander Pavel Vinogradov and Flight Engineer Jeff Williams, are in Baikonur, Kazakhstan, awaiting launch. They are scheduled to lift off at 9:30 p.m. EST Wednesday, March 29.

Managers reviewed preparations for the mission and approved moving forward with launch at the Soyuz Flight Readiness Review on Thursday. Although no spacewalk is planned from the station until July, managers also reviewed issues with spacewalking capability. They approved a temporary solution to allow a spacewalk if needed.

The concern with U.S. spacewalks surfaced when engineers found blisters on handrail bars during production work on the ground. The finding led to an ongoing evaluation to ensure the handrails' strength is sufficient. The evaluation is expected to be completed by the end of April. Meanwhile, the approved procedure for spacewalks, if one were to be needed, involves attaching crew safety tethers at the base of the handrails rather than on the bar of the rails.

Tokarev and McArthur also are continuing to look for Russian lithium hydroxide canisters on the station. The canisters are used to scrub carbon dioxide from Russian Orlan spacesuits and would be used if a spacewalk required using those suits. Regardless of the outcome of their search, a new supply of canisters will be carried to the station on a Progress cargo vehicle in April, and the next spacewalk planned using Russian spacesuits is set for August.

Vinogradov and Williams are planned to dock to the station at 11:19 p.m. EST next Friday. They will be joined by Brazil's first astronaut, Marcos Pontes, for launch. Pontes will spend eight days on the station under a commercial agreement with the Russian Federal Space Agency and return home with McArthur and Tokarev.

After a day of light duty and rest Tuesday, McArthur and Tokarev resumed normal operations, focusing on packing and preparing for the trip home. They packed personal items as well as hardware and science supplies that will return with them.

They also continued several science experiments that study plants in weightlessness and crystal growth in space. The studies included work with the Russian Matroshka and PLANT experiments and two Japan Aerospace Exploration Agency experiments, the Granada Crystallization Facility and the Photon Crystals Growth Facility. McArthur disassembled and stowed components from the U.S. Foot/Ground Reaction Forces During Spaceflight experiment. The crew recently completed that study which investigated the effects of weightlessness on the legs and feet.

McArthur took time to talk with students during two amateur radio sessions, one with the Sir James Lougheed Elementary School in Calgary, Alberta, Canada and a second with more than a thousand students in Rutigliano, Italy. McArthur has conducted 34 such sessions with students during his six months in orbit, more than any other station crew member.

Expedition 13 Commander Pavel Vinogradov, NASA Science Officer and Flight Engineer Jeff Williams and Brazilian Space Agency astronaut Marcos Pontes will dock to the station late Friday. Vinogradov and Williams will spend six months on the complex during Expedition 13. Pontes, flying under a commercial agreement with the Russian Federal Space Agency, will stay on the station for eight days.

The 162-foot tall Soyuz rocket launched from the Baikonur Cosmodrome at 9:30 p.m. EST. About 10 minutes later, the Soyuz was in orbit with its solar arrays and antennae extended. Docking is planned for 11:19 p.m. EST Friday.

Vinogradov, Williams and Pontes will open hatches at about 12:30 a.m. EST Saturday to join Expedition 12 Commander Bill McArthur and Flight Engineer Valery Tokarev inside the space complex.

The five space fliers will be available for a crew news conference at 10:55 a.m. EST Monday. Reporters at NASA's Johnson Space Center, Houston, Kennedy Space Center, Fla., and the Russian Mission Control Center in Korolev, Russia, may ask questions.

The two crews will spend about a week handing over operations of the station, and Pontes will conduct a series of research investigations. McArthur, Tokarev and Pontes return to Earth April 8. At landing, McArthur and Tokarev will have spent almost 190 days in space.

Earlier this week, McArthur found a supply of lithium hydroxide canisters used to scrub carbon dioxide from the air in Russian space suits during a spacewalk. The find ensures Russian suits can be used if a spacewalk is needed.

With Expedition 13 and Soyuz Commander Pavel Vinogradov at the controls, the Soyuz TMA-8 spacecraft automatically linked up to the Earth-facing port on the station's Zarya module at 11:19 p.m. EST Friday. The spacecraft were above China near the Russian, Kazakh and Mongolian borders at the time.

Aboard the Soyuz with Vinogradov were NASA Flight Engineer and Science Officer Jeff Williams and Brazilian Space Agency astronaut Marcos Pontes. Pontes will spend eight days on the complex under a commercial agreement with the Russian Federal Space Agency.

After systems checks, hatches between the Soyuz and the station were opened at 12:59 a.m. EST Saturday. Expedition 12 Commander Bill McArthur and Flight Engineer Valery Tokarev, nearing the end of their six-month mission on the station, greeted their colleagues with handshakes and hugs and offered the traditional bread and salt. Russian, American and Brazilian dignitaries viewed the docking from the Russian Mission Control Center in Korolev, outside Moscow, and congratulated the crews after hatch opening.

The new crew will now transfer cargo from the Soyuz to the station, deactivate the new Soyuz' systems and stow their launch and entry suits. Pontes will move his custom-made seatliner into the older Soyuz TMA-7 spacecraft that will bring him home, and he will begin several experiments. The two station crews will continue handover activities throughout the week, including robotics training with the station arm and detailed briefings on scientific experiments. Vinogradov and Williams will remain on board the station until September.

All five astronauts and cosmonauts will participate in a news conference at 10:55 a.m. EDT Monday. NASA Television will broadcast this event live.

Monday night, McArthur and Williams will "camp out" in the Quest airlock. They will sleep in the airlock, isolated from Tokarev, Vinogradov and Pontes, to test a new procedure that may reduce the preparation time for spacewalks. The new procedure will have spacewalkers stay in the airlock overnight at a lower air pressure to help purge nitrogen from their bodies to prevent decompression sickness. McArthur and Williams will begin their airlock stay at about 6:20 p.m. EDT Monday and finish at 3:30 a.m. EDT Tuesday.

McArthur, Tokarev and Pontes will leave the station aboard the Soyuz TMA-7 and land April 8.

Aboard the complex, one crew prepared for a return to Earth while another focused on taking the helm in orbit.

Expedition 12 Commander Bill McArthur, Flight Engineer Valery Tokarev and Brazilian astronaut Marcos Pontes head home Saturday, closing hatches as they leave the station at 1:35 p.m. EDT. They will undock their Soyuz spacecraft at 4:28 p.m. EDT. That sets the stage for a deorbit burn at 6:58 p.m. EDT to drop the 15,000-pound spacecraft out of orbit. The Soyuz will parachute to a landing at 7:48 p.m. EDT on the steppes of Kazakhstan.

Expedition 12's homecoming preparations began in earnest after last week's arrival of the 13th station crew, Commander Pavel Vinogradov and Flight Engineer Jeff Williams, who arrived with Pontes, Brazil's first astronaut. Pontes will have spent eight days on the station conducting experiments as part of a commercial agreement with the Russian Federal Space Agency.

This week began with a partially completed "campout" by McArthur and Williams in the Quest Airlock. The planned overnight stay in the airlock tested procedures that can shorten the time needed to prepare for future spacewalks.

Quest was sealed off from the rest of the station at 6:45 p.m. EDT Monday with McArthur and Williams inside, and its air pressure was later lowered to 10.2 pounds per square inch. The rest of the station remained at the normal air pressure of 14.7 pounds per square inch. An overnight stay at the lower air pressure helps purge nitrogen from the body, a necessary step to avoid decompression sickness. McArthur and Williams were awakened four hours into their sleep in the airlock by an error tone.

The tone was generated by software that monitors the composition of air on the station. Flight controllers opted to end the campout test Tuesday at 12:43 a.m. EDT, open the airlock hatch to the station, and allow the crew to go back to sleep. Despite the glitch, all of the test objectives were achieved. Engineers are reviewing data to determine whether changes are needed to use the technique during the STS-115 shuttle mission later this year. Engineers could decide to repeat the test at another time.

On Wednesday, Williams trained with the station's robot arm, Canadarm2. Late this week, McArthur briefed Williams on payload operations in the Destiny laboratory while Tokarev, the Soyuz commander, stowed equipment and payloads in the Soyuz for the trip home. Tokarev also reviewed procedures for the undocking, entry and landing with flight controllers at the Russian Mission Control Center outside Moscow.

With them was Marcos Pontes, Brazil's first astronaut.

The Soyuz spacecraft with McArthur, Tokarev and Pontes landed in central Kazakhstan, about 30 miles northeast of Arkalyk, at 7:48 p.m. EDT, Saturday. The crew's families will greet them at Star City, Russia, near Moscow, early Monday. McArthur and Tokarev will remain in Star City for post-flight debriefings before returning to Houston later this month. McArthur and Tokarev launched from the Baikonur Cosmodrome, Kazakhstan, Sept. 30, 2005.

They spent 189 days, 18 hours and 51 minutes in space. During their mission, they conducted two spacewalks and relocated their Soyuz spacecraft twice, becoming the first ISS crew to dock to every Russian docking port on the complex. They also became the first two-person station crew to conduct a spacewalk in both Russian and U.S. spacesuits. Pontes flew to the station with the Expedition 13 crew last week as part of a commercial agreement with the Russian Federal Space Agency, Roscosmos. He spent eight days on the station conducting experiments.

The new station crew, Expedition 13 Commander Pavel Vinogradov and Flight Engineer and NASA Science Officer Jeff Williams, will have light duty for the next few days as they rest from a busy handover. They will remain in orbit for six months. The crew plans to perform two spacewalks and greet two space shuttle crews during their expedition.

Joining them during their stay on the station will be Thomas Reiter, a European Space Agency astronaut from Germany, also flying under a commercial agreement with Roscosmos. Reiter is scheduled to come to the station on the Space Shuttle Discovery's STS-121 mission, targeted for a July launch.

Reiter will be the first non-Russian, non-U.S. long-duration crew member on the station. His arrival will bring the station crew size to three for the first time since May 2003, when the crew size was reduced to conserve supplies in the wake of the Columbia accident.

Shuttle Atlantis' STS-115 mission is also scheduled during Expedition 13 and will resume major assembly of the station. The shuttle and station crews will work together to add another set of batteries and solar arrays to the complex.

The crew's work has included station maintenance, medical and other experiments and standard daily exercise.

Expedition 13 Commander Pavel Vinogradov and Flight Engineer and NASA Science Officer Jeff Williams said farewell to their predecessors last Saturday. The Expedition 12 crew and a visiting Brazilian astronaut undocked that afternoon and landed in Kazakhstan at 7:48 p.m. EDT.

Vinogradov and Williams had light duty Sunday and Monday, a break after completing eight days of extensive handover activities with their counterparts.

Maintenance work included a three-and-one-half hour scheduled replacement of station toilet components on Tuesday. Both crew members also took time to talk with two Russian news organizations and participants at a Russian school children's aerospace festival.

On Wednesday, Russian President Vladimir Putin called the crew from the Kremlin. Putin's call came on the 45th anniversary of the first human spaceflight by Yuri Gagarin, a landmark event commemorated by the Russian holiday Cosmonautics Day. That date, April 12, was also the 25th anniversary of the first NASA space shuttle launch in 1981.

Putin told the crew it was a pleasure to see representatives of the United States and Russia working together on the same spacecraft. During the light-hearted exchange, Vinogradov invited Putin to visit the space station.

The crew continued loading the station's Progress cargo craft with trash and conducted physical evaluations and experiments Thursday. Vinogradov and Williams practiced an emergency evacuation drill Friday. Throughout the week, they had time to familiarize themselves with their new home.

Vinogradov and Williams will remain in orbit for six months. During that time, they plan to welcome two space shuttles and perform two spacewalks. Shuttle Discovery's STS-121 mission, targeting a launch no earlier than July 1, will bring European Space Agency astronaut Thomas Reiter aboard the station.

Reiter will increase the station crew size to three for the first time since May 2003 when the crew size was reduced to conserve station supplies following the Columbia accident.

Back on Earth for almost a week, Expedition 12 Commander Bill McArthur and Flight Engineer Valery Tokarev remain in Star City, Russia, near Moscow. They continue to undergo debriefing and rehabilitation after 190 days in space. With them is Marcos Pontes, Brazil's first astronaut, who launched with Expedition 13. He returned to Earth with the Expedition 12 crew after spending about eight days on the station conducting experiments.

Tentative plans call for McArthur to return to Houston later this month.

Expedition 13 Commander Pavel Vinogradov and Flight Engineer and NASA Science Officer Jeff Williams also had time set aside each day to continue to become familiar with their orbiting home.

In scientific work, Williams operated the Capillary Flow Experiment, which uses liquid silicone to study how fluids move in a microgravity environment. This portion of the experiment examined the interface between the liquid and the solid surface of the container. The results could be used by designers of systems for future spacecraft.

Williams also set up and activated cameras that will be remotely operated by middle school students to take photos of Earth through the station window. Called the Earth Knowledge Acquired by Middle School Students (EarthKAM) experiment, it allows students to study the Earth and then control a special digital camera mounted on the station. They photograph coastlines, mountain ranges and other geographic items of interest from the unique vantage point of space. More than 112 schools from eight countries have signed up for this session of the experiment. This is the 22nd time the experiment has been performed aboard the station.

Williams and Vinogradov completed the first of three sessions with the Renal Stone experiment, a study of whether potassium citrate can be used to reduce the risk of kidney stone formation. Astronauts have an increased risk of developing kidney stones because urine calcium levels are typically much higher in space. The crew recorded all consumed food and drinks and collected urine samples for later return to Earth. An understanding of the crew's diet during the urine collection timeframes will help researchers determine if the excess calcium in the urine is due to diet or a response to the microgravity environment.

The Expedition 13 crew also spent several hours practicing the use of a manual docking system for next week's arrival of the ISS Progress 21 cargo vehicle. The computer-based training will ensure they're ready to take control of the Progress if the automated system does not work properly. The 21st Progress to visit the station is scheduled to launch from the Baikonur Cosmodrome in Kazakhstan at 12:03 p.m. EDT Monday, and dock with the space station at 1:40 p.m. EDT Wednesday.

A planned reboost of the station was aborted before any engines were fired this week when downlink telemetry showed one of two sunshade covers on the Zvezda Service Module thrusters was not fully open. The station's onboard software detected that the cover was not properly opened and did not ignite the thrusters. The firing was designed to test two thrusters that have not been used since Zvezda docked to the station in July 2000. Zvezda has several other thrusters that could be used if needed. Engineers at the Russian Mission Control Center in Korolev are reviewing data and considering whether additional tests are required.

Friday the crew talked with experts in Mission Control, Houston, about an electrical repair procedure planned for Monday. The pair will replace a failed type of circuit breaker called a Remote Power Control Module (RPCM) in the Destiny Laboratory. The RPCM failed during the last crew's stay aboard the station, and power for several systems has been routed by an alternate path until it is replaced.

Vinogradov and Williams will remain in orbit for six months. During that time, they expect to welcome two space shuttles and perform two spacewalks. European Space Agency astronaut Thomas Reiter will join the Expedition 13 crew when the Space Shuttle Discovery arrives on the STS-121 mission, targeted for launch no earlier than July 1. Reiter will increase the station crew size to three for the first time since May 2003 when it was reduced to conserve supplies following the Columbia accident. The payload operations team at NASA's Marshall Space Flight Center, Huntsville, Ala., coordinates U.S. science activities on the station.

The ISS Progress 21 cargo spacecraft was launched today from the Baikonur Cosmodrome in Kazakhstan.

The new resupply ship lifted off at 12:03 p.m. EDT (10:03 p.m. Baikonur time). Less than 10 minutes later, the cargo ship reached orbit, and its solar arrays and navigational antennas were deployed for its two-day trip to the orbital outpost.

Two pre-programmed firings of the Progress' main engine are scheduled today to fine-tune the ship's path to the space station. Additional rendezvous maneuvers are planned Tuesday and Wednesday.

When the Progress launched, Expedition 13 Commander Pavel Vinogradov and Flight Engineer Jeff Williams were flying 219 miles over the Earth off the northeast of Australia. This is their 26th day in space and their 24th day on the complex.

Carrying 2.5 tons of food, water, fuel, oxygen, air, spare parts and other supplies, the new Progress is scheduled to automatically dock to the aft port of the station's Zvezda Service Module at 1:40 p.m. EDT Wednesday. The older ISS Progress 20 supply ship, which arrived at the station just before Christmas, will remain at the Pirs Docking Compartment until mid-June. It will be used to stow trash, and its supply of oxygen will help replenish the station's atmosphere.

The ISS Progress 21 is filled with 2.5 tons of food, fuel and personal items for the station's Expedition 13 crew.

Commander Pavel Vinogradov and Flight Engineer Jeff Williams will open the hatch to the supply ship once leak checks are completed later today. The crew will begin unloading items Thursday.

Automatically guided by its computers, the Progress docked to the aft port of Zvezda at 1:41 p.m. EDT as the spacecraft and the station sailed 219 miles above Greece. The Progress was launched Monday from the Baikonur Cosmodrome in Kazakhstan.

The supplies include food, fuel, oxygen and air, clothing, experiment hardware and spare parts, as well as personal items from the crew's families. The new Progress joins an older Progress supply ship that arrived at the station's Pirs Docking Compartment just before Christmas. Progress 20 will remain docked until mid-June. It will be used to stow trash, and its supply of oxygen will help replenish the station's atmosphere.

ISS Progress 21 holds 1,918 pounds of propellant for the Russian thrusters, 103 pounds of oxygen and air in tanks as a backup supply for the oxygen generated by the Russian Elektron system and 661 pounds of water to augment the supplies already on board. The spacecraft's cargo also includes more than 2,300 pounds of spare parts, experiment hardware and life support components.

The ISS Progress 21 cargo spacecraft, which launched from the Baikonur Cosmodrome in Kazakhstan on Monday, docked at the station Wednesday. The ship was the first supply shipment for Expedition 13 Commander Pavel Vinogradov and Flight Engineer Jeff Williams, who have been in space for almost a month.

The spacecraft brought fresh fruit and other foods, gifts from home, fuel, water, oxygen, spare parts and science gear. Two Progress cargo craft are now docked at the complex. Oxygen supplies from ISS Progress 20, which arrived in December, continue to be used to replenish the cabin air when required. The crew is loading that Progress with trash and unneeded equipment. The spacecraft will be jettisoned from the complex in mid-June.

Early in the week, Williams replaced a Remote Power Control Module, a type of circuit breaker, in the station's Destiny laboratory. The power control module had not been functioning for some time, and electricity for many lab systems had been delivered via an alternate path. To gain access to the worksite for replacement of the component, Williams had to disassemble and remove his sleeping compartment. Mission Control sequentially powered off many lab systems and lights to facilitate the replacement. Williams accomplished all the work ahead of schedule, and the new power control module has been functioning well.

Science activities aboard the station during the past week included work by Williams with the Capillary Flow Experiment, which is an investigation of fluid behavior in weightlessness that may assist in the design of future spacecraft. The crew members also completed urine collection and notes about their food consumption for an experiment studying the formation of kidney stones in weightlessness.

Vinogradov completed routine maintenance of the station's Elektron system. It was powered off much of the week and reactivated today. The Elektron provides oxygen for the cabin air from water.

Plans for next week include an engine firing to boost the station's altitude on Thursday, May 4; continued unloading of the newly arrived Progress vehicle; and periodic crew health checks.

Most of the week was focused around routine maintenance and inspections. Williams completed checks of the refrigerated centrifuge, updated the inventory system and took samples of potable water for routine testing. He also changed the cooling water used in the U.S. spacesuits to ensure that the pumps work and to prevent microbial growth in the water tanks.

Vinogradov did similar jobs in the station's Russian segment – completing an inspection of the pressure hull in the Zvezda living quarters, performing maintenance of the ventilation system in Zvezda and testing emergency vacuum valves in the Atmosphere Purification System.

On Wednesday, the crew updated onboard laptop computers. Williams began to install new software on the Medical Equipment Computer, but stopped to allow ground specialists to troubleshoot some difficulties he encountered. The problem was resolved and the task will be rescheduled for Williams. Vinogradov installed and tested new software on a Russian laptop.

Both crew members spent time packing unneeded gear inside the ISS Progress 20. The 20th Progress to visit the station is docked to the Pirs compartment and will be jettisoned from the complex in mid-June to burn up in the atmosphere. Russian flight controllers also fired the newer ISS Progress 21 cargo craft's engines for about six and a half minutes on Thursday to boost the station’s altitude by about 1.7 miles. The Progress 21 is docked at the aft docking port of the Zvezda module.

Williams kicked off the first Expedition 13 session of the Pore Formation and Mobility Investigation this week. It is an experiment that studies bubbling that occurs in weightlessness as liquids cool and turn into solids. It provides insight into how materials solidify in space and may benefit similar processes used in industry on Earth. The experiment is performed in the Microgravity Science Glovebox in the Destiny Lab.

The crew took time this week to reach out to more than 1,500 students, teachers and NASA personnel participating in a Space Day educational event at NASA's Goddard Space Flight Center, Greenbelt, Md. The event was part of a larger program highlighting NASA Explorer Schools as well as a collaboration between NASA and America Online (AOL).

Williams also spoke to students in the Inuit community of Kuujjuaq, Canada, via HAM radio. More than 340 students attend the school, which is located 900 miles north of Montreal at the base of Ungava Bay.

Using the microgravity science glovebox, Williams began the second of three sessions Wednesday of the Pore Formation and Mobility Investigation experiment. This experiment studies bubbling that occurs in weightlessness as liquids cool and solidify.

Williams will begin his first Saturday Science activity this weekend with the Cellular Biotechnology Operations Support Systems Fluid Dynamics Investigation. This is a series of experiments to improve fluid mixing techniques and to control bubble distribution for cell culture in orbit.

On May 4, ISS Progress 21 engines were used to reboost the station. Afterward, an error message indicated the Zvezda Service Module computers couldn't command the Progress engines to reconfigure for normal operations. The reboost was not affected. Engineers have determined the most likely cause of the message was a software error, which will be corrected. Meanwhile, a procedural change will allow the Progress thrusters to be used. Vinogradov and Williams continued to unpack supplies from that cargo vehicle.

Last week, engineers detected a small reduction of nitrogen pressure in the liquids unit of the oxygen-generating Elektron. To isolate the source of the leak, Russian flight controllers asked Vinogradov to turn off the machine. They have identified the small leak and plan to operate the Elektron as needed. A spare liquids unit is onboard.

The Elektron will remain deactivated until after a June 1 spacewalk. Engineers originally had planned to turn it off next week to reconfigure ventilation lines and to install a new hydrogen vent before the extravehicular activity. Meanwhile, oxygen from tanks in the ISS Progress 20 cargo vehicle is being added to the station's cabin.

On Thursday, Williams practiced using the station's robotic arm. He and Vinogradov spoke Wednesday with reporters from the StarDate syndicated Radio Network and WISN-TV of Milwaukee.

During the spacewalk, the crew will repair and retrieve U.S. and Russian hardware.

Expedition 13 Commander Pavel Vinogradov and NASA Flight Engineer and Science Officer Jeff Williams gathered equipment for the spacewalk, charged batteries for the Russian Orlan suits they will wear and checked out systems in the Pirs Docking Compartment airlock. The spacewalk will be staged from Pirs.

This will be the 65th spacewalk in support of station assembly and maintenance and the 18th conducted from this airlock. This will be the sixth spacewalk in Vinogradov's career and the second for Williams.

The crew members will climb into their spacesuits next Tuesday to test their mobility and to handle tools they will use while conducting their work outside. Vinogradov and Williams shifted their wake and sleep cycles this week to match the hours they will work on June 1. They will enjoy some off-duty time this weekend before resuming spacewalk preparations on Monday, with final communications and systems checks on their suits.

During the spacewalk the crew will install a new hydrogen vent valve on the hull of the Zvezda Service Module to bypass a similar valve that is clogged. The vent valve is part of the Russian Elektron oxygen-generation system that separates oxygen and hydrogen from water in the device's plumbing unit. The oxygen is then circulated into the cabin atmosphere while hydrogen is released overboard.

The spacewalkers will also recover a thruster residue collection device from Zvezda, retrieve a contamination monitoring device and a package of biology experiments and reposition a cable for a navigation antenna on the aft end of Zvezda to be used next year for the unpiloted rendezvous and docking of the new European Automated Transfer Vehicle.

Williams will also replace a camera on the station's Mobile Base System railcar that moves up and down the truss of the complex.

On the maintenance front, Vinogradov finished replacing a gas analyzer device for the Russian carbon dioxide removal system, known as Vozdukh. It had been operating at a slightly decreased rate in cleansing carbon dioxide from the cabin atmosphere. Russian specialists reactivated the system following the installation of the new gas analyzer. Vozdukh is now operating normally.

As part of the Crew Earth Observations experiment, Williams snapped the first shots of the Cleveland volcano erupting on the Aleutian Islands in Alaska. From their perspective in orbit, astronauts have been the first to spot and confirm the volcanic eruptions on several occasions. This is the first early sighting of a new eruption in recent years.

On Tuesday, Williams discussed the progress of his mission with The Associated Press Television Network and conducted an amateur radio discussion with students at a school in Venice, Italy.

Williams began runs of an experiment, designated the Investigating the Structure of Paramagnetic Aggregates from Colloidal Emulsions. The fluid physics experiment, last operated during Expedition 7, studies the behavior of fluids that change their properties when in a magnetic field. It obtains basic data on a new class of smart materials that can be used to improve or develop new brake systems, seat suspensions robotics, clutches, airplane landing gear and vibration damper systems.

Williams also continued checking the camera for the ground-commanded Binary Colloidal Alloy Test, or BCAT-3 activity. The EarthKAM camera and equipment is taking time-lapse photography once every hour of BCAT sample 3. BCAT-3 uses small particles called colloids to study fundamental physics. It gathers data that may provide insight into a wide range of applications, from the development of new pharmaceuticals to new rocket engines. NASA's payload operations team at the agency's Marshall Space Flight Center, Huntsville, Ala., coordinates U.S. science activities on the station.

During the spacewalk, the crew will repair and retrieve U.S. and Russian hardware.

Expedition 13 Commander Pavel Vinogradov and NASA Flight Engineer and Science Officer Jeff Williams gathered equipment for the spacewalk, charged batteries for the Russian Orlan suits they will wear and checked out systems in the Pirs Docking Compartment airlock. The spacewalk will be staged from Pirs.

This will be the 65th spacewalk in support of station assembly and maintenance and the 18th conducted from this airlock. This will be the sixth spacewalk in Vinogradov's career and the second for Williams.

The crew members will climb into their spacesuits next Tuesday to test their mobility and to handle tools they will use while conducting their work outside. Vinogradov and Williams shifted their wake and sleep cycles this week to match the hours they will work on June 1. They will enjoy some off-duty time this weekend before resuming spacewalk preparations on Monday, with final communications and systems checks on their suits.

During the spacewalk the crew will install a new hydrogen vent valve on the hull of the Zvezda Service Module to bypass a similar valve that is clogged. The vent valve is part of the Russian Elektron oxygen-generation system that separates oxygen and hydrogen from water in the device's plumbing unit. The oxygen is then circulated into the cabin atmosphere while hydrogen is released overboard.

The spacewalkers will also recover a thruster residue collection device from Zvezda, retrieve a contamination monitoring device and a package of biology experiments and reposition a cable for a navigation antenna on the aft end of Zvezda to be used next year for the unpiloted rendezvous and docking of the new European Automated Transfer Vehicle.

Williams will also replace a camera on the station's Mobile Base System railcar that moves up and down the truss of the complex.

On the maintenance front, Vinogradov this week finished replacing a gas analyzer device for the Russian carbon dioxide removal system, known as Vozdukh. It had been operating at a slightly decreased rate in cleansing carbon dioxide from the cabin atmosphere. Russian specialists reactivated the system following the installation of the new gas analyzer. Vozdukh is now operating normally.

As part of the Crew Earth Observations experiment, Williams snapped the first shots of the Cleveland volcano erupting on the Aleutian Islands in Alaska. From their perspective in orbit, astronauts have been the first to spot and confirm the volcanic eruptions on several occasions. This is the first early sighting of a new eruption in recent years.

On Tuesday, Williams discussed the progress of his mission with the Associated Press Television Network and conducted an amateur radio discussion with students at a school in Venice, Italy.

Williams began runs of an experiment, designated the Investigating the Structure of Paramagnetic Aggregates from Colloidal Emulsions, or InSPACE. The fluid physics experiment, last operated during Expedition 7, studies the behavior of fluids that change their properties when in a magnetic field. InSPACE obtains basic data on a new class of smart materials that can be used to improve or develop new brake systems, seat suspensions robotics, clutches, airplane landing gear and vibration damper systems.

Williams also continued checking the camera for the ground-commanded Binary Colloidal Alloy Test, or BCAT-3 activity. The EarthKAM camera and equipment is taking time-lapse photography once every hour of BCAT sample 3. BCAT-3 uses small particles called colloids to study fundamental physics. It gathers data that may provide insight into a wide range of applications, from the development of new pharmaceuticals to new rocket engines. NASA's payload operations team at the agency's Marshall Space Flight Center, Huntsville, Ala., coordinates U.S. science activities on the station.

Commander Pavel Vinogradov and Flight Engineer Jeff Williams had a busy weekend with closeout tasks and station configurations after the spacewalk last week. They finished the cleanup and stowage of the Orlan spacesuits and related tools.

The crew members enjoyed light duty days on Monday and Tuesday, resting up after the extended spacewalk and its follow up activities. They resumed a normal work and sleep schedule Wednesday. Another off-duty day for the crew is scheduled for Monday.

The crew attempted to reactivate the Russian Elektron oxygen-generating system this week following the replacement of its external hydrogen vent valve during the June 1 spacewalk. After several attempts, the Elektron began operating but failed about seven hours later. Vinogradov checked the vent lines associated with the refurbishment effort during the spacewalk and they appeared to be clear and operating normally.

Another attempt to restart Elektron earlier today proved unsuccessful, leading Russian specialists to believe that the problem is due to a failed power unit. A spare unit was located by Vinogradov and will be installed on Sunday. The crew members have at least a week of oxygen available in the cabin atmosphere before they would need to use supplies out of the ISS Progress 21 cargo ship tanks. The Elektron problem has had no impact on station operations and ample alternate supplies of oxygen are available.

This afternoon, the ISS Progress 21 thrusters were used to boost the station by a little less than one mile, placing the complex at the correct altitude for the launch and docking of the next cargo vehicle, ISS Progress 22.

That supply spacecraft is scheduled to launch June 24 from the Baikonur Cosmodrome in Kazakhstan, and will dock to the station on June 26 at the Pirs docking compartment port, which currently houses the older ISS Progress 20. It will be jettisoned on June 19 to make way for the new cargo vehicle.

Other work this week included some final spacewalk tool stowage tasks and the reconfiguration of the station's systems, including the communications system in the Russian Zvezda Service Module and the Pirs airlock.

The crew conducted a successful communications test with NASA's Dryden Flight Research Center, Calif., and White Sands Test Facility, N.M., ground sites and performed routine emergency fire drill training. They also inspected portable breathing apparatus and fire extinguishers.

Williams participated in two amateur radio sessions, the first with the Salt Brook Elementary School in New Providence, N.J., and a second with the Scarlett Middle School, a 2004 NASA Explorer School in Ann Arbor, Mich. Both crew members participated in an in-flight interview with the Web site team associated with the U.S. State Department's Bureau of Educational and Cultural Affairs.

Williams, who also serves as the NASA's station science officer, ran a session of two colloid experiments: Investigating the Structure of Paramagnetic Aggregates from Colloidal Emulsions or InSpace and Binary Colloidal Alloy Test or BCAT. Vinogradov worked with two Russian life science experiments -- URAGAN, which is a ground and space based system for predicting natural and manmade disasters, and DIATOMEA, an ocean observations program.

Commander Pavel Vinogradov and Flight Engineer Jeff Williams had a busy weekend with closeout tasks and station configurations after the spacewalk last week. They finished the cleanup and stowage of the Orlan spacesuits and related tools.

The crewmembers enjoyed light duty days on Monday and Tuesday to rest after the extended spacewalk and its follow up activities, but resumed a normal work and sleep schedule Wednesday. Another off-duty day for the crew is scheduled Monday.

The crew attempted to reactivate the Russian Elektron oxygen-generating system this week following the replacement of its external hydrogen vent valve during the June 1 spacewalk. After several attempts, the Elektron began operating but failed about seven hours later. Vinogradov checked the vent lines associated with the refurbishment effort during the spacewalk and they appeared to be clear and operating normally.

But another attempt to restart Elektron earlier today proved unsuccessful, leading Russian specialists to believe that the problem is due to a failed power unit. A spare was located by Vinogradov and will be installed on Sunday for another attempt to bring the system back on line. The crew has at least a week of oxygen available in the cabin atmosphere before it would need to use supplies out of the Progress 21 cargo ship tanks. The Elektron problem has had no impact on station operations and ample alternate supplies of oxygen are available.

This afternoon, the ISS Progress 21 thrusters were used to reboost the station by a little less than one mile, placing the complex at the correct altitude for the launch and docking of the new ISS Progress 22 cargo vehicle. Progress 22 is scheduled to launch June 24 from the Baikonur Cosmodrome in Kazakhstan, and will dock to the station on June 26 at the Pirs Docking Compartment port.

That docking port currently houses the older Progress 20 resupply ship, which will be jettisoned on June 19 to make way for the new cargo vehicle.

Other work this week included some final spacewalk tool stowage tasks and the reconfiguration of the station’s systems, including the communications system in the Russian Zvezda Service Module and the Pirs Docking Compartment airlock.

The crew conducted a successful communications test with the Dryden Flight Research Center and White Sands Test Facility ground sites and performed routine emergency fire drill training. They also inspected portable breathing apparatus and fire extinguishers.

Williams participated in two amateur radio sessions, the first with the Salt Brook Elementary School in New Providence, N.J., and a second with the Scarlett Middle School, a 2004 NASA Explorer School in Ann Arbor, Mich. Both crewmembers participated in an in-flight interview with the website team associated with the State Department's Bureau of Educational and Cultural Affairs.

Williams who serves as the station’s science officer, ran a session of two colloid experiments – InSpace (Investigating the Structure of Paramagnetic Aggregates from Colloidal Emulsions) and BCAT (Binary Colloidal Alloy Test). Vinogradov worked with two Russian life science experiments - URAGAN, which is a ground and space based system for predicting natural and manmade disasters, and DIATOMEA, an ocean observations program.

The crew also continued to prepare for the arrival of the Space Shuttle Discovery, which is set for launch July 1.

On Monday, Pavel Vinogradov and Jeff Williams watched as the ISS Progress 20 cargo vehicle automatically backed away from the station's Pirs docking port, making room for the next one's arrival. The new Progress is scheduled to launch from the Baikonur Cosmodrome at 11:08 a.m. EDT June 24 and dock to the station at about 12:30 p.m. EDT June 26. It will bring about 2.5 tons of equipment and supplies to the orbiting outpost.

Vinogradov took a refresher course on the Toru manual docking system Monday. Vinogradov would use the system to guide the cargo craft in the event its primary automated docking system did not function properly.

Throughout the week the station crew also prepared for Discovery's anticipated arrival. On Tuesday, Vinogradov and Williams reviewed the timeline of activities for the shuttle mission and held a conference with mission experts on the ground. On Friday, the crew continued to prepare U.S. spacesuits that will be used during the shuttle visit.

They also continued to pack equipment that will be returned to Earth on Discovery. On Wednesday, Williams installed the centerline berthing camera system in a window of the station's Unity connecting module. The camera view will assist with the attachment of a pressurized logistics module named Leonardo, which will be carried aboard Discovery to that module's port. The Leonardo module will be attached to Unity for unloading and reloading during the mission. It will be loaded in Discovery's cargo bay for the trip home.

Also on Wednesday, Vinogradov worked with the Russian experiment that studies self-propagating combustion materials. The investigation looks at mechanisms for forming high-porosity, heat-resistant, thermal insulating materials for spacecraft.

Williams spent more than three hours Thursday on station robotic arm activities, first training with a simulation program on a laptop computer and then exercising the arm itself. Supported by flight controllers on the ground, he moved the Canadarm2 in much the same way he will during Discovery's visit. He left it parked in position for Discovery's arrival.

While Williams worked with the robotic arm, flight controllers noted elevated spin motor command currents and vibrations on one of the station's four control moment gyroscopes, "CMG 3." The indications returned to normal several hours later, and the gyroscope has continued to perform normally.

Filled with 2.5 tons of food, fuel and supplies for the station's Expedition 13 crew, the ISS Progress 22 automatically docked at 12:25 p.m. EDT as the spacecraft and the station sailed 220 miles above northern Africa. The 22nd Progress to visit the station was launched Saturday from the Baikonur Cosmodrome in Kazakhstan.

Commander Pavel Vinogradov and Flight Engineer Jeff Williams will open the hatch to the supply ship once leak checks are completed later Monday. The crew will begin unloading items Tuesday.

The supplies include oxygen and air, clothing, experiment hardware and spare parts, as well as personal items from the crew's families. The new Progress joins an older Progress supply ship that arrived at the station's Zvezda Service Module in April. Progress 21 will remain docked until mid-September. It will be used to stow trash, and its supply of oxygen will help replenish the station's atmosphere when required.

ISS Progress 22 holds 1,918 pounds of propellant for the Russian thrusters, 108 pounds of oxygen and air as a backup supply for the oxygen generated by the Russian Elektron system and 264 pounds of water to augment onboard supplies. The new cargo also includes 2,800 pounds of spare parts, experiment hardware and life support components.

The experiment hardware includes items that will be used by European Space Agency astronaut Thomas Reiter once he arrives via the Space Shuttle Discovery's STS-121 mission. This flight will return the station to three crew members for the first time since 2003.

The new resupply ship, the 22nd Progress to visit the station, lifted off at 10:08 a.m. CDT (9:08 p.m. Baikonur time). Less than 10 minutes later, the cargo ship reached orbit, and its solar arrays and navigational antennas were deployed for the two-day trip to the orbital outpost.

Two pre-programmed firings of the Progress’ main engine are scheduled Saturday to fine-tune the ship’s path to the space station. Additional rendezvous maneuvers are planned Sunday and Monday.

When the Progress launched, Expedition 13 Commander Pavel Vinogradov and Flight Engineer Jeff Williams were flying 220 miles over the Earth off the west coast of Chile. Saturday was their 106th day in space and their 104th day on the station.

Carrying 2.5 tons of food, water, fuel, oxygen, air, spare parts and other supplies, the Progress is scheduled to automatically dock to the Pirs Docking Compartment at 11:27 a.m. CDT Monday.

The ISS Progress 20 supply ship that arrived at the station just before Christmas was undocked and deorbited last Monday and burned up in the Earth’s atmosphere. The ISS Progress 21 craft, which arrived in April, remains docked to the aft port of the Zvezda Service Module. That Progress will be used to stow trash and supply oxygen to replenish the station's atmosphere when required. The spacecraft won’t be discarded until mid-September.

Filled with 2.5 tons of food, fuel and supplies for the station's Expedition 13 crew, the ISS Progress 22 automatically docked to the Pirs airlock at 11:25 a.m. CDT as the spacecraft and the station sailed 220 miles above northern Africa. The 22nd Progress to visit the station was launched Saturday from the Baikonur Cosmodrome in Kazakhstan.

Commander Pavel Vinogradov and Flight Engineer Jeff Williams will open the hatch to the supply ship once leak checks are completed later Monday. The crew will begin unloading items Tuesday.

The supplies include food, fuel, oxygen and air, clothing, experiment hardware and spare parts, as well as personal items from the crew's families. The new Progress joins an older Progress supply ship that arrived at the station’s Zvezda Service Module in April. Progress 21 will remain docked until mid-September. It will be used to stow trash, and its supply of oxygen will help replenish the station’s atmosphere when required.

ISS Progress 22 holds 1,918 pounds of propellant for the Russian thrusters, 108 pounds of oxygen and air as a backup supply for the oxygen generated by the Russian Elektron system and 264 pounds of water to augment onboard supplies. The new cargo also includes 2,800 pounds of spare parts, experiment hardware and life support components.

The experiment hardware includes items that will be used by European Space Agency astronaut Thomas Reiter once he arrives via the Space Shuttle Discovery's STS-121 mission. This flight will return the station to three crew members for the first time since 2003.

Discovery’s launch is scheduled for 3:49 p.m. EDT Saturday. Discovery's STS-121 mission will return the station to three crew members for the first time since 2003, when European Space Agency astronaut Thomas Reiter joins crew members Jeff Williams, flight engineer and Pavel Vinogradov, commander. To get ready for upcoming STS-121 spacewalks, the crew flushed cooling loops in the Quest airlock and U.S. spacesuits, configured airlock systems and tools, and reviewed robotic arm procedures. They checked out a ship-to-ship communications system that will be used for conversations with Discovery's crew during rendezvous and disconnected the station’s Common Cabin Air Assembly heat exchanger. That device will be returned to Earth aboard Discovery along with other equipment in the Italian-built Leonardo Multipurpose Logistics Module. Discovery will bring about 5,000 pounds of supplies to the station carried aboard the logistics module.

The crew also completed a mid-mission session of the renal stone experiment by collecting urine samples and logging all of the food and drinks consum