ISS 1996 Credit - NASA via Marcus Lindroos

In 1987-1993 the Russians successfully assembled and operated the 124-metric ton Mir station. The station's modules were evolved from those of the secret military Almaz station of the 1970s. Mir and its crews whirled round and round the world, through the collapse of the Soviet Union and Russian economic meltdown. By 1993, Russia had acquired unmatched experience in long-duration human flight, but it was apparent that there was no money for the follow-on Mir-2.

At the same time, NASA had scaled down its space station in the seventh redesign in nine years. This more modest station Alpha deleted most of the original science experiments, but would still cost more than Clinton was willing to spend. In October 1993, with the gunfire of the coup attempt outside their windows, NASA negotiators in Moscow agreed to the 'International Space Station' (ISS), a merger of stations Alpha and Mir-2.

President Clinton's endorsement of the new Option A Space Station did little to help the project. In June 1993, a bid in Congress to kill the Station failed by a single vote (215-216). Scientists continued to be critical of the project, saying its benefits were more marginal than ever after the latest redesign and that the Station had lost its political mission following the end of the Cold War.

In September, NASA presented Clinton with two final options: the small 4-man US-only 'Alpha' Station approved in June or the larger and much more capable 6-crew 'Russian Alpha' design. President Clinton chose the latter option, essentially merging the American SS Freedom and Russian 'Mir-2' projects into a new International Space Station (ISS). The President also managed to strike a deal with Congress which established a fixed annual budget of $2.1 billion. The agreement was remarkably successful; the last attempt to cancel the project was rejected in the House of Representatives in 1994. Technologically, ISS reversed the continuing trend (since 1986) toward a smaller and less capable Station. The new configuration reintroduced the US laboratory and node modules into the design. ISS would have more science racks than Freedom and provided more power for experiments. The total mass in orbit was 370 metric tons, so the International Space Station weighed almost twice as much as Space Station Freedom.

A big plus according to NASA was that the Station now could be manned almost immediately, as soon as the Russian FGB and Service Modules had been launched. In contrast, Space Station Freedom would not have been capable of supporting a permanent crew before a dozen or so modules had been launched.

Aerospace mergers plus increased emphasis on commercial space made it easier for the new NASA Administrator, Dan Goldin, to reform the Space Station and NASA in general. The Space Station Program Office in Reston, Virginia was cancelled as NASA selected Boeing (which bought the space divisions of other Station contractors such as McDonnell-Douglas and Rockwell in the 1990s) as the new Station prime contractor. Boeing's contract from 1995 contained less NASA oversight than usual while giving the company and its Space Station 'integrated production teams' some financial rewards in case the projected goals were met. The Johnson Space Center now hosted the Station's new program office. All this greatly simplified the project's cumbersome management structure, although the efforts to avoid cost overruns and delays were not entirely successful.

European Space Agency contributions to the International Space Station program were seriously revised following the restructuring of the European manned spaceflight program in 1991-93. The November 1992 meeting in Granada decided to continue with a scaled back $3-billion Columbus module, but the French managed to force another reassessment in 1995 due to concerns about the US commitment to Space Station Freedom. The overall cost of the revised ESA programs was estimated to be $2 billion lower (at 1991 prices) than the original $10.8 billion projected for 1993-95. From 1993 to 2000, the total was projected to be about $25.7 billion, down from $29.7 billion.

ESA then merged its Columbus and manned space transportation plans into a single effort in 1994, to further reduce the overall cost of the $4.6-billion COF/CTV/ATV program.. In October 1995, ESA finally decided to remain a partner in the ISS project after France, Italy and Germany managed to reach a complicated compromise on what the contributions should be and how much they would cost. The Italians received Ariane-5 and Columbus contracts from France and Germany. The $1.4-billion Columbus Orbiting Facility was also approved. The second major project was the French-led Automated Transfer Vehicle designed to carry 9,000kg of cargo to ISS. It would cost $750 million to develop. The $1.7-billion Crew Transfer Vehicle capsule was however cut from the package, although France received $60 million for CTV studies.

In addition to its other contributions, the ESA Council also approved a 'complementary' ISS Phase 2 program in July 1994 for early development of laboratory and computer support equipment used on the US and Russian ISS segments, before Columbus was launched. Important projects included a computer system and European Remote Arm for the Russian Service Module. When ESA decided not to launch the Columbus Orbiting Facility on its Ariane-5 rocket, it had to reimburse the American's for using the Space Shuttle. As part of a barter deal signed in March 1997, ESA contributed experimental racks and freezer units for the US laboratory. ESA also contributed two Node modules worth $115 million free of charge, in return for receiving a 'free' Space Shuttle flight from the Americans to launch the Columbus Orbiting Facility (COF). The nodes were built by Alenia Spazio and based on the same basic pressurized module as the COF and Multi-Purpose Logistics Modules. One of the nodes carried the International Space Station's environmental control and life-support system and crew quarters since the US habitation module had been postponed due to cost overruns.

Brazil joined the ISS project in 1999. China remained outside the project, pursuing its own independent program. Despite its additional capabilities, the International Space Station's Fiscal 1994-2000 budget was actually lower than for any of the other redesigns. However, the lower cost came at a price since ISS would not be assembled as quickly as the other options. All the other redesigns planned to end the assembly phase by 2001. The International Space Station assembly sequence would now require another five years beyond that.

The ISS removed some of the space transportation burden from the Shuttle's back since the other international partners were to contribute their own rocket. However, ISS was also more challenging because its orbit had to be accessible to rockets launched from Russia's Baikonur spaceport at 45 degrees northern latitude. The greater ISS orbital inclination meant that the Shuttle's net payload was substantially reduced. NASA developed a new super lightweight aluminum-lithium propellant tank to boost the Shuttle's performance while gradually privatizing Space Shuttle management to save money. The pressurized modules and about 70% of the hardware developed for the old Space Station Freedom project were adopted for the International Space Station.

A major concern was whether the Americans would have the nerve to stay the course when inevitable mishaps occurred. The station, like Mir, required constant maintenance. It could not be shut down if America stopped shuttle flights for years as it did after the *Challenger* explosion. Russian engineers calculated that there was a 23% chance that the exposed Service Module would be punctured by orbital debris during the lifetime of the station. Although the alloy and type of construction there would contain any puncture within a 70x70-centimetre panel, they believed an impact on the American section would result in fractures propagating quickly across a 400x400-centimetre area, leading to explosive decompression, an uncontrollable spin and rapid break-up of the station. Fortunately the probability of such an impact was only 2%.

The inevitable mishap occurred in 2003, when the shuttle Columbia disintegrated during reentry. NASA stayed the course, although the shuttle was grounded for 30 months and the ISS assembly schedule delayed by a further five years.

No project better illustrated the roller coaster effect of inconsistent space policies than the International Space Station, which was being assembled by the American, European, Russian, Japanese and Canadian national space agencies. The Space Station program was started, at NASA's urging, by President Reagan in 1984. Reagan wanted to launch a major space project shortly before the elections, since it would create jobs in important states such as California, Texas and Florida. He also wanted to invite other NATO countries to participate in the U.S-led project, since the Soviet Union had been launching international crews to their Salyut space stations since 1971. The new American station would of course be bigger and better, sending a clear signal to the world about American leadership and dominance in space. However, the space station was also going to tie the emerging European and Japanese national space programs closer to the U.S.-led project, thereby preventing those nations from becoming major, independent competitors too. Commercial space was booming and competition from other Western nations had become a major worry for the U.S. aerospace industry. There was considerable commercial interest in the Space Shuttle, and some market analysts felt a space station could be economically important as a research lab or manufacturing centre. The Reagan Administration generally extolled the virtues of free enterprise and small business, and the space station was regarded as an important market for private space investors.

The National Aeronautics and Space Administration had its own institutional reasons for wanting a large space station. After the Apollo lunar landings in the late 1960s, the agency had fallen on hard times in the 1970s when the space budget was drastically reduced due to the high cost of the Vietnam War and social programs. NASA was barely able to secure funding for the Space Shuttle in 1972 as Apollo was cancelled. The space agency then had to exist on a virtual shoestring budget throughout the 1970s while struggling to complete the Shuttle development program. But the new Shuttle Transportation System (STS) turned out to be more expensive than expected when it finally became operational in 1982. STS was also unpopular with the Reagan Administration, who disliked the idea of having NASA rather than private industry run a 'national spaceline.' The senior NASA managers thus wanted another program to complement the Shuttle; something that would 'give STS something to do' while showcasing its versatility and usefulness. At the same time, the new project was going to provide much-needed employment for as many NASA centers and aerospace contractors as possible. NASA had been unable to afford hiring new employees for much of the 1970s, and it was hoped that a large space station would persuade more young engineers to join the agency.

Original article by Marcus Lindroos; updated by Mark Wade.

Typical orbit: 407 km circular orbit, 51.6 deg inclination. Electrical System: Solar panels.

• ISS Zarya.  Other Designations: Alpha-FGB. Manufacturer's Designation: 77KM. Part of: International Space Station. Class: Manned. Type: Space Station. Destination: Space Station Orbit. Nation: Russia. Agency: NASA. Manufacturer: Chelomei.

  The Russian Zarya FGB space tug was the cornerstone of the new International Space Station since it acted as an adapter between the US and Russian-built ISS segments and also provided some propulsion and propellant storage capabilities. It was closely based on the older Russian TKS spacecraft design that was intended as a ferry for the Almaz military station. The United States paid $220 million for the FGB (vs. $450 million for Lockheed's rejected 'Bus-1' option) and Khrunichev successfully completed the project on schedule and within budget. However, the launch had to be delayed by 17 months to November 1998 because the Russians were unable to complete their own ISS Zvezda service module on time.

  The Russian-built propulsion module that was the first element of the International Space Station. Launched by a three-stage Proton rocket, the Zarya control module, also known by the technical term Functional Cargo Block and the Russian acronym FGB provided the station's initial propulsion and power. The 20,000 kg pressurized module was launched on Nov. 20 1998 from the Baikonur Cosmodrome, Kazakhstan.

  The module was named Zarya, meaning "sunrise", in tribute to the new beginning in space that would be ushered in by the its launch as the first component of the International Space Station (and to finally use the name the engineers wanted to call the first Russian space station, Salyut 1, 28 years earlier). Its launch marked the beginning of an international venture of unprecedented scale.

  Less than two weeks after Zarya reached orbit, the Space Shuttle Endeavour rendezvoused with it and attached the U.S.-built Unity connecting module. Zarya was to provide orientation control, communications and electrical power attached to Unity for several months before the launch of the third component, a Russian-provided crew living quarters and early station core known as the Service Module. The Service Module would enhance or replace many functions of the Zarya. Later in the station's assembly sequence, the Zarya module was to be used primarily for its storage capacity and external fuel tanks.

  Zarya's solar arrays and six nickel-cadmium batteries provided an average of 3 kilowatts of electrical power. Each of the two solar arrays was 11 m long and 3 m wide. Using the Russian Kurs system, the Zarya would perform an automated and remotely piloted rendezvous and docking with the Service Module in orbit. Its docking ports would accommodate Russian Soyuz piloted spacecraft and unpiloted Progress resupply spacecraft. The module was modified to allow it to be refueled by a Progress vehicle docked to its down-facing port if necessary. The module's 16 fuel tanks held more than 6 metric tons of propellant. The attitude control system for the module included 24 large steering jets and 12 small steering jets. Two large engines were available for reboosting the spacecraft and making major orbital changes.

  After reaching the initial elliptical orbit and separating from the Proton's third stage, a set of pre-programmed commands automatically activated the module's systems and deployed the solar arrays and communications antennae. On ensuing days after several operational tests, the module was commanded to fire its engines and circularize its orbit at an altitude of about 390 km, the orbit at which Endeavour would rendezvous and capture the spacecraft using the Shuttle's robotic arm.

  The U.S.-funded and Russian-built Zarya was a U.S. component of the station although it was built by the Khrunichev State Research and Production Space Centre (KhSC) in Moscow under a subcontract to The Boeing Co. for NASA. It was shipped to the Baikonur Cosmodrome, Kazakhstan, launch site to begin launch preparations in January 1998.

  Typical orbit: 399 km circular orbit, 51.5 deg inclination. Maximum Diameter: 4.15 m (13.61 ft). Mass: 20,000 kg (44,000 lb). Main Engine: KRD-442. Main Engine Propellants: 12,000 kg (26,000 lb). Electrical System: Solar cells. Associated Launch Vehicle: Proton 8K82K.

• ISS Unity.  Part of: International Space Station. Class: Manned. Type: Space Station. Destination: Space Station Orbit. Nation: USA. Agency: NASA. Manufacturer: Boeing.

  Unity was the first U.S.-built component of the International Space Station. It consisted of a six-sided connecting module and passageway, and was the primary cargo of Space Shuttle mission STS-88, the first mission dedicated to assembly of the station.

  The Unity connecting module, technically referred to as node 1, would lay a foundation for all future U.S. International Space Station modules with six berthing ports, one on each side, to which future modules would be attached. Built by The Boeing Company at a manufacturing facility at the Marshall Space Flight Center in Huntsville, Alabama, Unity was the first of three such connecting modules that would be built for the station. Sometimes referred to as Node 1, the Unity module measured 15 feet in diameter and 18 feet long.

  Meeting in Space

  Carried to orbit aboard the Space Shuttle Endeavour, Unity would be mated with the already orbiting Zarya control module, or Functional Cargo Block (Russian acronym FGB), a U.S.-funded and Russian-built component that would had been launched earlier aboard a Russian rocket from Kazakhstan. In addition to connecting to the Zarya module, Unity eventually would provide attachment points for the U.S. laboratory module; Node 3; an early exterior framework, or truss for the station; an airlock; and a multi-windowed cupola.

  Vital Resources

  Essential space station resources such as fluids, environmental control and life support systems, electrical and data systems were routed through Unity to supply work and living areas.

  More than 50,000 mechanical items, 216 lines to carry fluids and gases, and 121 internal and external electrical cables using six miles of wire were installed in the Unity node. The detailed and complex hardware installation required more than 1,800 drawings. The node was made of aluminum.

  Pressurized Mating Adapters

  Two conical docking adapters would be attached to each end of Unity prior to its launch aboard Endeavour. The adapters, called pressurized mating adapters (PMAs), allow the docking systems used by the Space Shuttle and by Russian modules to attach to the node's hatches and berthing mechanisms. One of the conical adapters would attach Unity to the Zarya, while the other would serve as a docking port for the Space Shuttle. The Unity node with the two mating adapters attached, the configuration it would be in for launch, was about 36 feet long and weighs about 25,600 pounds.

  Attached to the exterior of one of the pressurized mating adapters were computers, or multiplexer-demultiplexers (MDMs), which would provide early command and control of the Unity node. Unity also would be outfitted with an early communications system that would allow data, voice and low data rate video with Mission Control, Houston, to supplement Russian communications systems during the early station assembly activities.

  Length: 11.00 m (36.00 ft). Maximum Diameter: 4.00 m (13.10 ft). Span: 4.00 m (13.10 ft). Mass: 11,600 kg (25,500 lb). Associated Launch Vehicle: Shuttle.

• ISS Zvezda.  Other Designations: Alpha-SM. Manufacturer's Designation: USM No. 176-01. Part of: International Space Station. Class: Manned. Type: Space Station. Destination: Space Station Orbit. Nation: Russia. Manufacturer: Korolev.

  The Zvezda service module of the International Space Station had its origins a quarter century before it was launched. The Mir-2 space station was originally authorized in the February 1976 resolution setting forth plans for development of third generation Soviet space systems. It would undergo many changes over the years, with only one thing remaining constant: the starting point was always the DOS-8 base block space station core module, built as a back-up to the DOS-7 base block used in the Mir station. When the International Space Station was agreed to, the $3-billion DOS-8 became the first Russian segment of the station, originally known as the Service Module.

  The original plan called for a first launch in June 1997 of the ISS Zarya tug followed by the Russian Service Module in September. ISS would then be permanently manned from January 1998 onwards. This launch schedule was delayed by more than two years due to Russia's economic problems.

  DOS-8 serial number 128 was originally designed to have a three year service life in space. This was later increased to five years. The spaceframe was completed in February 1985 and major internal equipment was installed by October 1986. Until Reagan's 1983 announcement of the Star Wars program, Mir-2 was to be a relatively modest station, a near-duplicate of Mir assembled after the end of its planned five year life.

  The decision by Soviet Premier Andropov to compete with America in military dominance from space lead to a huge expansion of Soviet space station plans. As design continued the station grew to immense proportions. The draft project for this greatly expanded station was approved by NPO Energia Chief Semenov on 14 December 1987 and announced to the press as 'Mir-2' in January 1988. The station would be built in a 65 degree orbit and consist mainly of enormous 90 metric ton modules. But the first launch, as always, was the DOS 8. Assembly of the station was expected to begin in 1993.

  As the Soviet Union disintegrated plans for this station were scaled down. By 1991 the Energia modules were out of the picture and the drastically reduced 'Mir 1.5', was under consideration. DOS-8 would be equipped by Buran with 37KBE power modules and two operational 37KBT biotechnology modules. By 1992 Buran was now out of the picture and the plan was reduced in scale again. These revised plans were approved by the Council of Chief Designers on 24 November 1992. Mir-2 would now consist of the DOS-8 core module, and a cross beam called the NEP (scientific-energy platform). The add-on modules were reduced in size for launch by either the Soyuz or Zenit launch vehicles.

  By November 1992 further financial difficulties and uncertainties with America's Freedom space station led Russia and the European Space Agency to open discussions on joint development and use of Mir-2. This circle was expanded in the summer of 1993 when Energia briefed NASA on the Mir-2. Finally in November 1993 Freedom, Mir-2, and the European and Japanese modules were incorporated into a single International Space Station. Among these was the Alpha Service Module - the DOS-8 station, finally to be launched as the second major ISS module during 2000.

  Improved space transportation capabilities were a major reason for bringing the Russians on board. NASA decided to use the existing 3-man Soyuz spacecraft as an interim 'lifeboat' for the Space Station while investigating more capable alternatives. The Russians also promised to provide -- and pay for -- cheap unmanned cargo transportation. However, the modified Progress M and MT versions were never built. Russia still committed to launch four standard Progress craft per year, but many Western observers doubted that the Russians would be able to deliver on those promises. The Russian Space Agency was strapped for cash and keeping the existing Mir space station in orbit until 2001 further drained resources from the International Space Station.

  Many ISS elements were also moved from Russian rockets to the US Space Shuttle as Russia's commitments to the station declined. The originally-planned Russian laboratory modules were replaced with larger FGB-derived design to save money. Boeing and Khrunichev announced in July 2000 that they would build a privately financed module, the 'Commercial Space Module', based on the FGB design and launched as early as 2002. The small Russian laboratory modules, Science and Power Platform, and most of the other components planned by the Russians were derived from the old 'Mir 1.5' plan. All of these Russian modules, except use of Soyuz and Progress spacecraft for station resupply, were in question by early 2001.

  Typical orbit: 179 x 332 km, 51.5 deg inclinaton. Maximum Diameter: 4.15 m (13.61 ft). Mass: 20,000 kg (44,000 lb). Electrical System: Solar cells. Associated Launch Vehicle: Proton 8K82K.

• ISS Destiny.  Part of: International Space Station. Class: Manned. Type: Space station module.

  American ISS module, a cylindrical structure that functioned as a science and technology module and the primary control module for the ISS.

  The Destiny Laboratory was comprised of three cylindrical sections and two endcones that contained the hatches through which astronauts enter and exit the module. Destiny was mated to the forward port of Unity. In Destiny were five systems racks that provided life-sustaining functions on board including electrical power, cooling water, air revitalization, and temperature and humidity control. Each rack weighs about 550 kg. Six additional racks were to be flown to Destiny on STS-102. Four standoffs provided raceways for module utilities / interfaces for ducting, piping, and wiring to be run to/from the individual racks and throughout the Lab. Twelve racks provided platforms for a variety of scientific experiments would follow on subsequent missions. In total, Destiny was to eventually hold 23 racks -- six each on the port and starboard sides and overhead, and five on the deck.

  Boeing began construction of the laboratory in 1995 at the Marshall Space Flight Center in Huntsville. Destiny was shipped to the Kennedy Space Center in Florida in 1998 and was turned over to NASA for pre-launch preparations in August 2000.

  Destiny's Laboratory Structure

  Internal to the laboratory were racks, rack standoffs, and vestibule jumpers. The lab racks housed the system hardware in removable modular units. The rack standoffs provided a volume for ducting, piping and wiring to be run to/from the individual racks and throughout the Lab. The racks interfaced to the piping and wiring in the standoff via outlets and ports located in the standoffs at the base end of each rack location.

  Jumpers in the vestibule, the area between Unity and Destiny, connected the piping and wiring between the two. Grounding straps between Unity and Destiny were installed. One side of the grounding strap was connected to the Active Common Berthing Mechanism (ACBM) on Unity, while the other end was connected to the Passive Common Berthing Mechanism (PCBM) on Destiny.

  Some of the mechanisms on Destiny were the CBMs (passive and active), hatches, and the laboratory window shutter. The ACBM was in the forward port of the laboratory. It was attached to the PCBM in Pressurized Mating Adapter 2 (PMA 2) when the PMA was berthed to the forward port of Destiny at the conclusion of the STS-98 mission. Destiny's ACBM could not be operated until the laboratory was activated. The PCBM on Destiny was located in the laboratory's aft port. The ACBM in Unity's forward port was to be latched to the laboratory's PCBM to berth Destiny to Unity.

  Each of the two berthing ports on Destiny contained a hatch. The aft hatch (hatch to Unity) was to remain normally open (unless a situation arises requiring a module to be isolated). The forward hatch was to be used as the main access to the orbiter until Node 2 arrived.

  Each hatch had a window. The hatches could be opened or closed from either side. The hatches had a pressure interlock feature, which prevented the hatch from being opened if there was a negative pressure across the hatch (higher pressure on the outside of the hatch).

  Destiny had an optical quality window (principally for Earth science observations) and a window shutter to protect the window from potential micrometeoroid and orbital debris strikes during the life of the ISS. The crew manually opened the shutter to use the window. The shutter was to be installed during the third scheduled space walk.

  Length: 8.40 m (27.50 ft). Basic Diameter: 4.20 m (13.70 ft). Maximum Diameter: 4.20 m (13.70 ft). Mass: 15,000 kg (33,000 lb).

• ISS Space Station Remote Manipulator System.  Part of: International Space Station. Class: Manned. Type: Space Station Module. Nation: Canada. Manufacturer: Spar.

  When the Space Station plan was changed in 1987, its satellite servicing element was postponed indefinitely. The Canadian robotic arm was now necessary for assembling the Station itself, since the Shuttle's existing 'Canadarm' manipulator only could handle 29.5t loads. The redesigned 'Canadian Mobile Servicing Center' would be used to dock the Shuttle and, possibly, payloads launched on expendable launchers to the Station.

  The 1987 Space Station redesign greatly increased the importance of the Canadian contribution to the international project. Canada joined the project in March 1985 and initially proposed an 'Integrated Servicing and Test Facility' that would have consisted of two robotic arms plus satellite repair facilities.

  The US was originally to provide a movable platform for the MSC, but this was cancelled in 1988 for budgetary reasons. The 1993 International Space Station redesign delayed the launch of the Space Station Remote Manipulator System (as it now was called) by at least four years, but the SSRMS remained a crucial part of ISS. In 1994, the Canadians considered canceling the project despite already having spent $500 million on it. The fate of the SSRMS' $150-million robotic 'hand', or Special Multipurpose Dexterous Manipulator, was unclear until April 1997 when the Canadian government announced it would be developed after all. The total cost of the project would be $1 billion.

  Article by Marcus Lindroos

• ISS Quest Joint Airlock.  Part of: International Space Station. Class: Manned. Type: Space station module.

  The Quest Joint Airlock was delivered to the ISS by STS-104 and installed onto the Unity module. In a series of spacewalks the astronauts moved the oxygen and nitrogen tanks onto the airlock exterior. The six metric ton Airlock consisted of two cylinders of four meters diameter and a total length six meters. The Airlock could be pressurized by the externally-mounted high pressure oxygen-nitrogen tanks, and was to be the sole unit through which all future EVAs were to take place. (Until that point, all EVA entries/exits had been through a Russian module in ISS, with non-Russians having to wear Russian space suits).

  Length: 6.00 m (19.60 ft). Basic Diameter: 4.00 m (13.10 ft). Maximum Diameter: 4.00 m (13.10 ft). Mass: 6,000 kg (13,200 lb).

• ISS Pirs.  Manufacturer's Designation: Energia. Part of: Progress M-SO. Class: Manned. Type: Space Station Module. Nation: Russia. Manufacturer: Korolev.

  Russian docking and airlock module for the International Space Station. The Stikovochniy Otsek No. 1 (SO1, Docking Module 1), article 240GK No. 1L, was built by Energia and derived from Soyuz hardware. It had a mass of around 3900 kg and was a 4.1 m long, 2.6 m diameter ovoid. The SO1 was named Pirs (Russian for "pier") and was delivered to the station by Progress M-SO1 in a completely automatic rendezvous and docking operation. Pirs provided extra clearance from the Station for ships docking underneath Zvezda, and was used as an airlock for spacewalks using the Russian Orlan EVA suits.

  Length: 4.10 m (13.40 ft). Basic Diameter: 2.60 m (8.50 ft). Maximum Diameter: 2.60 m (8.50 ft). Mass: 6,850 kg (15,100 lb). Associated Launch Vehicle: Soyuz 11A511U.

• ISS MPLM.  Part of: International Space Station. Class: Manned. Type: Space Station Module. Nation: USA. Agency: ESA. Manufacturer: Alenia.

  When the International Space Station (ISS) was redesigned again in 1993, it was decided to expand the original Mini-Pressurized Logistics Module design. The new Multi-Purpose Logistics Module was twice as long and could carry 9000 kg of cargo to ISS. The European Space Agency also became a partner, since Alenia Spazio would use the same pressurized module and some thermal subsystems in the Columbus Orbiting Facility as well. In return, ESA provided three environmental control and life-support system units for use in the Multipurpose Logistics Module. The module carried sixteen International Standard Payload Racks.

  Italy delivered the first 'Leonardo' Multi-Purpose Logistics Module to NASA in July 1998. Two more module -- 'Rafaelo' and 'Donatello' -- would also be delivered under the $300-million contract. Italian astronauts would receive greater use of the Station as well as crew training for two more ASI astronauts in return for the MPLM.

  Article by Marcus Lindroos

  Typical orbit: 407 km circular orbit, 51.6 deg inclination.

• ISS Columbus Orbiting Facility.  Part of: International Space Station. Class: Manned. Type: Space Station. Nation: Europe. Agency: ESA. Manufacturer: Alenia.

  In October 1993, ESA decided to further slash its overall budget by a combined $4.8 billion in 1994-2000. The Columbus space station module survived, but in a reduced form. It would now cost $900 million less than the proposed $3.1 billion through 2000. The new Columbus Orbiting Facility (COF) was shorter and lighter. It was based on the same Alenia-developed pressurized module as the Multi-Purpose Logistics Module.

  Its launch was postponed to the early 21st century when the Space Station was designed in 1993, in part because the European Space Agency wanted to reduce the near term cost by delaying the project. If the International Space Station were cancelled, the fallback plan was to convert the COF module into a small Man-Tended Free Flying platform. A manned Crew Transfer Vehicle space capsule and Automated Transfer Vehicle (logistics, resupply) would then give Europe an autonomous manned spaceflight capability. The COF module was small enough to be launched on an Ariane-5 rocket rather than the Shuttle, although this option was abandoned in the mid-1990s. In 1992, Daimler Benz Aerospace and Russia's NPO Energia also investigated the possibility of building a joint European/Russian free-flying platform as part of Russia's 'Mir-2' program before the Russian space station merged with the US-led International Space Station project.

  Article by Marcus Lindroos

  Typical orbit: 407 km circular orbit, 51.6 deg inclination.

• Spacehab.  Part of: International Space Station. Class: Manned. Type: Space Station Module. Destination: Space Station Orbit. Nation: USA. Agency: NASA-JSC. Manufacturer: Spacehab.

  Founded by Bob Citron in 1982, Spacehab Inc. was the only entrepreneurial company to successfully develop a commercial manned spaceflight module. Spacehab was initially formed to develop a 5000 kg pressurized module derived from ESA's Spacelab. The 3 meter long Spacehab module was carried inside the Shuttle cargo bay and provides 28.3 cubic meters of expanded habitable space for experiments and logistics transport to space stations.

  NASA agreed to sign a memorandum of understanding in December 1985, but its agreement with the European Space Agency prevented it from using competitive systems such as Spacehab's before 1989.

  Consequently, the company signed contracts with the main European Spacelab contractors (MBB/ERNO and Aeritalia) to take a share in Spacehab as well as serve as prime contractors. By 1986 some $1 million had been spent on the project and the company initiated negotiations with NASA, claiming some 350 customers had expressed interest in using the module. NASA turned down a request from Spacehab for Shuttle launches on a deferred payment basis in 1987, and also briefly considered canceling other commercial agreements with Space Industries Inc. and 3M as well. The agency informed Spacehab that no launches would be available before 1995 since the Shuttle was extremely overbooked following the Challenger accident. Spacehab then tried to sign up priority customers such as the Defense Department which would have forced NASA to assign Spacehab to an earlier flight. However, President Reagan's National Space Policy from February 1988 specifically ordered NASA to 'make best efforts' to launch Spacehab's $65-70 million cargo module on the Shuttle in the early 1990s. Federal regulations required NASA to open the expansion module to competition but Spacehab provided the only response by the 30 April 1990 deadline. NASA then agreed in principle to launch six commercial Spacehab flights by 1995, but the company initially found it difficult to raise capital.

  Spacehab finally signed a contract with NASA in December 1990 to lease two-thirds of the payload space for $184 million. An important mission was hardware tests for Space Station Freedom; the module could carry up to four Space Station-type experiment racks. NASA agreed to launch Spacehab eight times at a cost of $28.2 million per flight. More than $20 million had already been spent on the project by this time, and Chase Manhattan Bank agreed to provide a further $75 million after Spacehab offered to buy insurance if Congress cancelled the project. The company paid a 20% premium. Spacehab was almost cancelled in January 1992 when the House and Senate panels with NASA oversight indicated Congress only would pay $25 million in 1992 and $35 million in 1993. NASA had requested $39 million and $50 million, respectively. The House and Senate reached a compromise in March which allocated a $40 million budget for Spacehab in Fiscal Year 1992, and the investors (who had spent $44 million at that point plus another $50 million borrowed from Chase Manhattan Bank) said they were satisfied with the project's progress.

  The company then unveiled its first Spacehab module in May 1992. The partners expected to make a profit after six flights, which had been bought by NASA in 1990. Under the agreement, Spacehab bought launch services from NASA and leased capacity to users for $1.76 million per experiment locker. Each module had 50 lockers and a dedicated flight thus costs $79.8 million. The first flight took place in June 1993, but with 98% of the facility occupied by experiments managed and paid for by NASA.

  The company also investigated concepts other than the basic augmented Shuttle module, including Spacehab expansion modules for the Space Station. In 1986, Spacehab estimated a basic module would cost $15 million, rising to $40 million for a not-yet-approved advanced model that would have contained thermal control and augmented power and life support systems. The total cost of three basic modules was to be $50 million and Spacehab proposed a first mission in 1988 followed by three in 1989 and four in 1990. Proposed missions included Space Station technology testing and augmented 'construction shack' living quarters for assembly workers. NASA's problems with the Shuttle and Space Station forced the company to delay its first launch until 1994 while the space station module had to be cancelled.

  NASA signed a $54-million contract with Spacehab Inc. in August 1995 for Shuttle/Mir logistics flights. The deciding factor was Spacehab's faster turnaround between missions. Spacehab remained an active participant in the Shuttle/International Space Station program. The company proposed a new $30-40 million docking/logistics double module that would make it possible for the Shuttle to reboost the Space Station by 16 km per docking as opposed to just 4.8 kilometers. Spacehab was also collaborating with Russia on a commercial 'Enterprise' laboratory module.

  Article by Marcus Lindroos

  Typical orbit: 368 km circular orbit, 51.6 deg inclination. Length: 3.00 m (9.80 ft). Maximum Diameter: 4.50 m (14.70 ft). Span: 4.50 m (14.70 ft). Mass: 5,000 kg (11,000 lb). Associated Launch Vehicle: Shuttle.

• NASDA Japanese Experiment Module.  Part of: International Space Station. Class: Manned. Type: Space Station Module. Nation: Japan. Agency: NASDA.

  The Japanese Experiment Module (JEM) has been a rare island of stability in the often tumultuous Space Station program. Conceived in 1985, JEM consists of a pressurized laboratory mainly dedicated to advanced technology experiments, a logistics module, an unpressurized pallet for vacuum experiments in space plus a small robotic arm. The Japanese National Space Development Agency (NASDA) formally submitted the JEM proposal to NASA in March 1986. The Japanese Space Activities Commission recommended formal participation in the Space Station project five months later and the JEM design changed little since the mid-1980s.

  In 1986 the Japanese contribution was estimated to be worth $1.9-3.2 billion for a JEM launch in 1995. By 1990, the schedule had slipped by three years due to NASA budget cuts and Space Station cost overruns. The delays increased the JEM's total cost slightly, from $2.3 billion in 1986 to $2.63 billion in 1993, when the launch was postponed to 1999. Final hardware production began in the mid-1990s and the Japanese robotic arm was tested on a NASA Space Shuttle flight in August 1997. According to plans prior to the Columbia disaster, the JEM would be launched in 2002-03. As of 2007 it appeared the facility would be orbited in 2008.

  Like the other International Space Station modules, the interior of the Japanese Experiment Module (JEM) consisted of modular refrigerator-sized 'payload racks.' JEM had twelve such racks but some were required for the module's internal functions. Five racks were available for experiments.

  Typical orbit: 407 km circular orbit, 51.6 deg inclination. Associated Launch Vehicle: Shuttle.

• ISS Mini PLM.  Part of: International Space Station. Class: Manned. Type: Space Station Module. Nation: USA. Agency: ESA. Manufacturer: Alenia.

  As NASA's Space Station budget received further cutbacks, the agency was forced to consider more and more hardware paid for by foreign space agencies although Congress and private industry were opposed to it. In 1992, Italy's Alenia Spazio announced they would build a small Mini-Pressurized Logistics Module (MPLM) for the Space Shuttle, enabling it to carry 4500 kg of cargo to the Space Station. The MPLM might also be transformed into a small life sciences laboratory. Boeing had previously wanted to build the MPLM, but NASA could not afford to pay for it. Instead, the Italian space agency, ASI, would now finance the $400-million project in return for crew time and experiments on the Space Station.

  Article by Marcus Lindroos

  Typical orbit: 407 km circular orbit, 51.6 deg inclination.

• ISS Commercial Enterprise Module.  Part of: International Space Station. Class: Manned. Type: Space Station Module. Nation: USA. Manufacturer: Spacehab, Korolev.

  The Russian economic crisis provided some intriguing opportunities for private industry. Spacehab Inc. and NPO Energia announced a small commercially financed laboratory that would be launched on a Zenit rocket in 2003. The 'Enterprise' module would contain a windowed 'studio bay' giving crew members views of the Station, arriving vehicles and Earth. Loosely based on the Progress cargo spacecraft, the 'Enterprise' interior was to be divided into two sections - a 64 position equipment bay able to accommodate standardized Station Express racks, Shuttle mid-deck lockers and Spacehab module lockers - and the studio bay.

  Described as 'a large open space at the bottom end of the module,' the studio would be set up to generate high definition video (HDV) for broadcast and multimedia distribution. Life support in the module was designed to support an hour-long press conference by six crew members, or full-time occupation by one or two crew members. Communications would be handled through the Spacehab Universal Communications System (SHUCS), an Inmarsat-based L-band terminal and antenna. It was claimed this would give two-way Internet connectivity 'with a data rate similar to an ISDN connection.' Plans called for the Enterprise module to be mounted to the nadir port of Russia's Zarya Service Module, a site also claimed by Boeing and Russia's Khrunichev for their 'Commercial Space Module.' However, Spacehab and Energia had a signed agreement with the Russian Aerospace Agency granting them the nadir port, and Boeing had said it would let the Russian agency decide who in the end gets to use it.

  Article by Marcus Lindroos

  Typical orbit: 407 km circular orbit, 51.6 deg inclination. Associated Launch Vehicle: Proton 8K82K.

• ISS Russian Science and Power Platform.  Part of: International Space Station. Class: Manned. Type: Space Station Module. Nation: Russia. Manufacturer: Korolev.

  The RSPP was originally going to be launched on six Russian Proton rockets fairly early during the ISS assembly phase. The Science and Power Platform would only power the Russian laboratory modules, so it was not crucial to the success of the whole ISS project. Further Russian cutbacks led to the RSPP being cancelled and replaced with one of the four American solar arrays.

  Typical orbit: 407 km circular orbit, 51.6 deg inclination.

• Transhab Module.  Part of: International Space Station. Class: Manned. Type: Space Station Module. Nation: USA. Manufacturer: NASA Houston.

  Cost overruns soon forced NASA to consider other options for the International Space Station's habitation module. The space agency originally intended to use the same 8.2-meter long habitation module as the final 1991 Space Station Freedom design. In late 1998, NASA's Johnson Space Center proposed a much larger and lighter inflatable 8-meter diameter 'Transhab' module that also could be converted into crew quarters for future manned missions to the Moon and Mars. It was also possible that the module could be built and paid for by private industry and leased to NASA, although the exact configuration wasn't clear. Transhab and the 8.2-meter module appeared to be equally expensive ($100 million in 1998) and NASA had not made a final decision.

  Article by Marcus Lindroos

  Typical orbit: 407 km circular orbit, 51.6 deg inclination. Associated Launch Vehicle: Shuttle.

• 1985 February 1 - DOS-8 structure completed. -
  DOS-8 serial number 128 was originally designed as the backup to Mir and possibly the core module of Mir-2.

• 1986 October 1 - DOS-8 major equipment installation complete. -
  DOS-8 serial number 128 was originally designed as the backup to Mir and possibly the core module of Mir-2.

• 1987 December 14 - Mir-2 draft project approved -
  The draft project for this greatly expanded station was approved by NPO Energia Chief Semenov on 14 December 1987 and announced to the press as 'Mir-2' in January 1988. The station would be built in a 65 degree orbit and consist mainly of enormous 90 tonne modules. But the first launch, as always, was the DOS 8. Assembly of the station was expected to begin in 1993.

• 1992 November 24 - Council of Chief Designers review revised Mir-2 design -
  With abandonment of the Buran shuttle and 37K modules, the Mir-2 design was cut back again. Mir-2 returned to its original planned 65 degree orbit, and would be assembled and flown separately from Mir. It would now consist of the DOS-8 core module, and a cross beam called the NEP (scientific-energy platform). This was equipped with equipment already proven on Mir: MSB retractable solar panels, Sfora thruster packages, small scientific packages as demonstrated on Kvant.The add-on modules now used the Progress-M service module as a tug, and were reduced in size for launch by either the Soyuz or Zenit launch vehicles.

• 1993 November 1 - International Space Station -
  Cost escalation of the US Space Station Freedom, and financial difficulties in Russia, led to a summer 1993 briefing of NASA by NPO Energia on Mir-2. In November 1993 Freedom, Mir-2, and the European and Japanese modules were incorporated into a single International Space Station.

• 1995 January 1 - X-38 development authorised. - Program: ISS.
  When doubts about the availability of Soyuz developed in 1995, NASA proceeded with development of the X-38, a NASA Johnson concept - a smaller version of the X-24 lifting body with a parafoil.

• 1996 June 1 - Soyuz TMA, X-38 selected as ISS lifeboat over Alpha Lifeboat - Program: ISS.
  The Alpha lifeboat was based on the Zarya reentry vehicle with a solid retrofire motor and cold gas thruster package. The design was rejected in favor of use of modified Soyuz TM in short term, US X-38 in long term.

• 1998 January 1 - Zarya FGB delivered to Baikonur -
  The U.S.-funded and Russian-built Zarya was a U.S. component of the International Space Station.

• 1998 December 8 - EVA STS-88-1 - Program: ISS. Crew: Ross, Newman. Flight: STS-88.
  Began assembly of International Space Station. Connected cables between Zarya and Unity modules.

• 1998 December 10 - EVA STS-88-2 - Program: ISS. Crew: Ross, Newman. Flight: STS-88.
  Continued assembly of International Space Station. Connected cables between Zarya and Unity modules and deployed antennae.

• 1998 December 13 - EVA STS-88-3 - Program: ISS. Crew: Ross, Newman. Flight: STS-88.
  Completed initial assembly of International Space Station. A canvas tool bag was attached to the exterior of Unity to provide tools for future assembly workers. Also disconnected some docking cables, so that Unity and Zarya could no longer undock.

• 1999 May 30 - EVA STS-96-1 - Program: ISS. Crew: Jernigan, Barry. Flight: STS-96.
  On May 30 at 02:56 GMT Tammy Jernigan and Dan Barry entered the payload bay of space shuttle Discovery from the tunnel adapter hatch. During the space walk they transferred equipment to the exterior of the station.

• 2000 May 22 - EVA STS-101-1 - Program: ISS. Crew: Williams Jeffrey, Voss. Flight: STS-101.
  The crew reattached the US crane, attached the Russian Strela transfer boom, and replaced a faulty antenna on the Unity node. EVA handrails were fixed to the station exterior for use on later spacewalks.

• 2000 September 11 - EVA STS-106-1 - Program: ISS. Crew: Lu, Malenchenko. Flight: STS-106.
  Astronauts Lu and Malenchenko made a spacewalk on September 11 beginning at 04:47 GMT. They rode the RMS arm up to Zvezda and began installing cables, reaching a distance of 30 meters from the airlock when installing Zvezda's magnetometer.

• 2000 October 15 - EVA STS-92-1 - Program: ISS. Crew: McArthur, Chiao. Flight: STS-92.
  The astronauts connected cables between Z1 and Unity, relocated the SASA S-band antenna on Z1, and deployed Z1's SGANT Ku-band antenna. They then took the port ETSD (EVA stowage) box from the Spacelab pallet and installed it on Z1.

• 2000 October 16 - EVA STS-92-2 - Program: ISS. Crew: Wisoff, Lopez-Alegria. Flight: STS-92.
  Wakata aboard the shuttle used the RMS arm to unberth the PMA-3 docking unit from the SLP pallet at 16:14 GMT, and docked it to Unity at 17:40 GMT. Wisoff and Lopez-Alegria first unbolted PMA-3 from the SLP and then guided Wakata through the delicate alignment process as PMA-3 was removed from the bay and attached to the Station.

• 2000 October 17 - EVA STS-92-3 - Program: ISS. Crew: McArthur, Chiao. Flight: STS-92.
  The astronauts installed two 58 kg DDCU DC-to-DC converter units atop the International Space Station's Z1 Truss. The DDCUs, will convert electricity generated by the solar arrays to be attached during the next shuttle mission. The spacewalkers also completed power cable connections on both the Z1 truss and newly installed docking port, PMA-3. They connected and reconfigured cables to route power from Pressurised Mating Adapter-2 to PMA-3 for the arrival of Endeavour and the STS-97 crew next month. They also attached a second tool storage box on the Z1 truss, providing a place to hold the tools and spacewalking aids for future assembly flights. McArthur stocked the boxes with tools and hardware that had been attached to the Unity module. STS-96 Astronauts Tammy Jernigan and Dan Barry had left the tools on the outside of Unity during a May 1999 spacewalk.

• 2000 October 18 - EVA STS-92-4 - Program: ISS. Crew: Wisoff, Lopez-Alegria. Flight: STS-92.
  Jeff Wisoff and Mike Lopez-Alegria each jetted slowly through space above Discovery's cargo bay, demonstrating the small rescue nitrogen powered SAFER backpack (Simplified Aid for EVA Rescue). This would be used in the future to help a drifting astronaut regain the safety of the spacecraft. Each astronaut performed one 15 meter flight with the SAFER while attached to the shuttle with a long tether. Lopez-Alegria and Wisoff, with Koichi Wakata operating the arm, also completed a series of wrap-up tasks during the EVA. They removed a grapple fixture from the Z1 truss, opened and closed a latch assembly that will hold the solar array truss when it arrives, deployed a tray that will be used to provide power to the U.S. Laboratory Destiny, and tested the manual berthing mechanism latches that will support Destiny. Wisoff opened and closed the latches on the capture assembly for the P6 solar arrays using a pistol grip tool. With it he made more than 125 turns to open the latches, then closed and reopened them. He left the capture latch, called 'the claw,' ready to receive the solar arrays, to be installed by the STS-97 crew. An exercise to test techniques for returning an incapacitated astronaut to the air lock was cancelled because of time constraints.

• 2000 December 4 - EVA STS-97-1 - Program: ISS. Crew: Tanner, Noriega. Flight: STS-97.
  The first STS-97 spacewalk began with airlock depress and hatch open at 1831 GMT on December 3. The suits went to battery power at 1835 GMT and Joe Tanner and Carlos Noriega left the airlock around 1845 GMT. Around 1932 GMT the RMS arm berthed P6 on the Z1 truss, and the astronauts manually latched it in place by 1940 GMT. There were some problems releasing latches on the solar array wings, but the first solar array began to deploy at 0123 GMT on December 4. This was the "starboard" (+X) array, wing SAW-2B. The port (-X) array, SAW-4B, was left undeployed. The astronauts closed the hatch at 0202 GMT on Dec 4 and repressurized at 0209 GMT. The P6 PVR radiator was deployed on the +Y side of the IEA at 0414 GMT on December 4. The SAW-4B wing was deployed starting at 0052 GMT on December 5.

• 2000 December 5 - EVA STS-97-2 - Program: ISS. Crew: Tanner, Noriega. Flight: STS-97.
  The spacewalk began on December 5 with depress at 1718 GMT, hatch open around 1719 GMT and battery power at 1721 GMT. Repress was at 2358 GMT. The astronauts connected up P6 to the station, inspected the tension wires on wing 2B, and relocated the S-band antenna to the top of P6. They unlatched the aft TCS radiator, which was deployed sometime early on December 6.

• 2000 December 7 - EVA STS-97-3 - Program: ISS. Crew: Tanner, Noriega. Flight: STS-97.
  Astronauts Noriega and Tanner on December 7 performed EVA-3 to fix the tension in the SAW-2B solar array on the Station. Airlock depress was at 1609 GMT, hatch open at 1610 GMT and battery power at 1613 GMT. The astronauts left the airlock a few minutes later, probably about 1620 GMT. After fixing the solar array they installed the FPPU device to measure plasma conditions near the top of P6 and performed a few other minor tasks. They returned to the airlock at around 2110 GMT, closing the hatch at 2119 and repressurizing at 2122.

• 2001 February 10 - EVA STS-98-1 - Program: ISS. Crew: Jones, Curbeam. Flight: STS-98.
  Tom Jones and Bob Curbeam began the first STS-98 spacewalk from the ODS airlock on Atlantis, supervising the ISS/Destiny assembly operations. The airlock was depressurized at 1544 GMT. PMA-2 was berthed on Z1 at 1650 GMT; Destiny was unberthed from the payload bay at 1735 GMT and docked to Unity at 1900 GMT. At 1935 GMT Curbeam was connecting ammonia coolant lines when a leaking connector sprayed ammonia into space, contaminating his suit. He was ordered to stay in sunlight to bake off the ammonia. At around 2311 GMT the spacewalkers returned to the airlock, closing the hatch at 2318 GMT. A new depressurization for decontamination was begun at 2342 GMT, with the airlock fully depressurized at 2350 GMT. The hatch was then opened and closed quickly at 2351-2352 GMT, to flush the airlock of any ammonia residue. This last event was not counted as an EVA by NASA.

• 2001 February 12 - EVA STS-98-2 - Program: ISS. Crew: Jones, Curbeam. Flight: STS-98.
  STS-98 EVA-2 began at 1555 GMT on February 12 with depressurization of the airlock. The astronauts went to battery power at 1559 GMT. The PMA-2 docking port was attached to Destiny at 1728 GMT. The Power Data Grapple Fixture (PDGF) was removed from its location on an adaptive payload carrier on the port side of the payload bay (probably bay 5P) and installed on Destiny. The PDGF will be used by the Station's robot arm, and is an improved grapple fixture with electrical power and data ports. The hatch was closed at 2240 GMT and the airlock was repressurized at 2249 GMT

• 2001 February 14 - EVA STS-98-3 - Program: ISS. Crew: Jones, Curbeam. Flight: STS-98.
  On the third STS-98 EVA the airlock was depressurized at 1443 GMT, with hatch open at around 1445 and battery power at 1448. The spare SASA S-band antenna was unberthed from an adapter beam in the payload bay (around bay 4P?) and installed on Z1. The +X (starboard) TCS radiator on P6, launched on the previous mission, was deployed at 1649 GMT. The astronauts completed the spacewalk with repressurization of the airlock at 2013 GMT

• 2001 March 11 - EVA ISS EO-2-1 - Program: ISS. Crew: Voss, Helms. Flight: ISS EO-2.
  On March 11 Jim Voss and Susan Helms made a spacewalk from Discovery's airlock. A PAD device used to attach equipment to the RMS arm floated free and Voss retrieved a spare one from Unity, putting the walk behind schedule. The astronauts installed the Lab Cradle Assembly and the Rigid Umbilical on Destiny and disconnected the umbilicals connecting the PMA-3 docking port to Unity. The astronauts then spent two-and-a-half hours back in the depressurized airlock in case their help was needed during the move of PMA-3. Thomas used the RMS arm to unberth PMA-3 from the nadir port on Unity and relocated it to the port port location, freeing up the nadir for the MPLM. The airlock was depressurized at 0508 GMT and repressurized at 1408 GMT.

• 2001 March 13 - EVA STS-102-1 - Program: ISS. Crew: Thomas Andrew, Richards Paul. Flight: STS-102.
  The airlock was depressurized at 0518 GMT and the hatch opened at 0520 GMT. The astronauts took the External Stowage Platform from the ICC carrier to the port side of the Destiny module, and then installed the spare Pump Flow Control System on it. The ESP was used to store on-orbit-spare equipment. Next they hooked up cables on the robot arm's umbilical, and travelled up to the top of the P6 tower to fix a solar array latch - it just needed a good thump - and inspect the FPP experiment. The astronauts returned to the airlock at 1132 GMT and began repressurizing at 1144 GMT.