Little Joe II
Status: Retired 1966. First Launch: 1963-08-28. Last Launch: 1966-01-20. Number: 5 . Gross mass: 63,300 kg (139,500 lb). Height: 26.20 m (85.90 ft). Diameter: 3.96 m (12.99 ft). Apogee: 23 km (14 mi).
From Chariots for Apollo: A History of Manned Lunar Spacecraft, NASA SP-4205:
Early in the contract, North American and Houston engineers had agreed on a flight-test program, putting boilerplate command and service modules through structural tests and checking out the abort escape system. In mid1961, while he was still with NASA before joining North American in 1962, Alan Kehlet had suggested using a fin-stabilized, clustered-rocket, solid-propellant booster for these tests. The "Little Joe II" (named after the Project Mercury test vehicle) would be able to propel a full-sized Apollo reentry spacecraft to velocities as great as those in the critical portions of the Saturn trajectory and to altitudes of 60,900 meters. The tests would be a simple and fairly inexpensive way of determining - in flight - the full-scale spacecraft configuration concepts, systems performance, and structural integrity. Tests of the launch escape system at maximum dynamic pressure would be most important. In May 1962 the Convair Division of General Dynamics was selected to develop the vehicle and named Jack Hurt as its program manager.
Although launch sites at Wallops Island, Virginia; Eglin Air Force Base, Florida; and the Cape were considered, the New Mexico desert north of El Paso, Texas, was picked early in the spring of 1962 as the Little Joe II test area. The Army's White Sands Missile Range (WSMR) seemed the most suitable for Little Joe II ballistic flights.
NASA engineers expected to conduct three kinds of tests at White Sands: (1) pad aborts, in which a solid-fueled rocket mounted on a tower attached to the top of the command module would pull the spacecraft away as it would have to do if the Saturn threatened to blow up on the launch pad; (2) maximum-dynamic-pressure ("max q") tests, in which the rocket would pull the spacecraft away from the launch vehicle if the booster veered off course shortly after launch; and (3) high-altitude tests, in which the rocket would haul the spacecraft away from the launch vehicle if the Saturn were unable to boost its payload to orbital flight.
Apollo leaders also expected to flight-test the lunar module in New Mexico, using the Little Joe II booster.
The first Little Joe II, a qualification test vehicle without a payload, was launched successfully on 28 August 1963.
At White Sands, New Mexico, on the morning of 13 May 1964, a Little Joe II launch vehicle rammed Boilerplate (BP) 12 to an altitude of 4,700 meters, to see if the launch escape system could propel the spacecraft away from the booster after it had reached transonic speed. Only one incident marred an otherwise successful flight. A parachute riser broke during descent, collapsing one of the three main parachutes. The boilerplate landed safely on the two remaining parachutes, in what one engineer later called "a welcome unplanned result of the test."
As 1964 drew to a close, the Little Joe II abort test program at White Sands was nearing its third and, in many ways, most crucial launch. Because of their fixed fins, the first two solid-fueled rockets had been somewhat erratic in flight. Jack B. Hurt's people at the Convair plant of General Dynamics in San Diego then built a relatively simple attitude control and autopilot system for the rest of their vehicles to allow hydropneumatic operation of "elevons," like ailerons, in each of the four fins while in flight. In addition, for the "max q" (maximum dynamic pressure) and high-altitude abort tests coming up, small reaction control motors were installed in the fin fairings to increase the precision of aiming control to the test points desired.
Vehicle No. 12-51-1, as it was called, with four Recruit and two Algol motors, was the most powerful Little Joe II yet flown, intended to develop 1,500 kilonewtons (340,000 pounds of thrust to lift itself and its cargo - BP-23 and the launch escape tower - more than 9 kilometers high. The whole assemblage, weighing 41,500 kilograms, was pointed toward the north at a point in space where the launch escape system, fitted with canards, would pull the capsule and boost protective cover away from the Little Joe II while traveling at a speed of Mach 1.5. This area was in the middle of the region where a Saturn V ought to experience max q.
At precisely 8:00 on the morning of 8 December, Little Joe II roared upward, straight and true. Thirty-six seconds later - almost out of sight and two seconds, or 900 meters, early - the planned abort took place. After an 11-second coast period, the canards deployed, and the capsule tumbled four times in its turnaround before stabilizing blunt-end forward and jettisoning the escape system. The boost protective cover shattered slightly more than expected, but the two drogue parachutes deployed. Its three main parachutes opened, and BP-23 drifted gently to rest, 11,000 meters up range from the launch site, after 7.5 minutes of flight. Max q had been higher than predicted, but all else had worked well; at the end of 1964, Little Joe II, with its payload, was ready for more stringent flight tests.
Meanwhile, flight testing of the lunar module within the earth's atmosphere was finally ruled out when Langley discovered in wind tunnel investigations that the Little Joe II-lander combination would be aerodynamically unstable.
Several dozen newsmen gathered at White Sands Missile Range, New Mexico, on 19 May to watch Mission A-003, an abort test of a boilerplate spacecraft at an altitude of 35,000 meters. At 6 that morning, the Little Joe II ignited and rammed its payload skyward. A few seconds after liftoff, a fin-vane at the base of the booster stuck and started the 13-meter-tall spacecraft-booster combination spinning like a bullet. Twenty-six seconds into the flight and still on a true course, the vehicle started coming apart. The abort-sensing system signaled the launch escape tower rocket to fire and pull the spacecraft away at an altitude of 4,000 meters.
While newsmen watched the fluttering remains of the Little Joe II, BP-22's parachutes lowered it gently to the desert floor. Apollo had another answer: the launch escape system worked in a real abort situation.
Little more than a month later, on 29 June, the launch team in New Mexico prepared to test an abort off the pad. The year before, a similar test had proved the escape tower rocket could jerk the spacecraft safely away from an exploding launch vehicle. But both the spacecraft and its escape system had since gained weight. In the second test, the rocket pulled the spacecraft higher in the air and farther downrange than expected.
Before starting Apollo-Saturn IB launches, however, the operations people had to clean up one outstanding matter in New Mexico. NASA had hoped to finish the Little Joe II abort qualification program by the end of 1965, but on 17 December the Flight Readiness Board refused to accept the booster and canceled a launch set for the next day. A month later, at 8:15 on the morning of 20 January 1966, the last Little Joe II headed toward an altitude of 24 kilometers and a downrange distance of 14 kilometers. Then, as designed, the launch vehicle started to tumble; the launch escape system sensed trouble and fired its abort rocket, carrying the command module away from impending disaster. All went well on Mission A-004-the launch, the test conditions, the telemetry, the spacecraft (Block I production model 002), and the post flight analysis. The spacecraft windows picked up too much soot from the tower jettison motor, but the structure remained intact. Little Joe II was honorably-retired, its basic purpose - making sure the launch escape and earth landing systems could protect the astronauts in either emergency or normal operations - accomplished.
|Little Joe II 6-1-0 American test vehicle. Single stage vehicle consisting of 6 x Recruit + 1 x Algol 1D fired in sequence.|
|Little Joe II 4-2-0 American test vehicle. Single stage vehicle consisting of 4 x Recruit + 2 x Algol 1D fired in sequence.|
|Little Joe II 0-3-3 American test vehicle. Single stage vehicle consisting of 6 x Algol 1D motors.|
|Little Joe II 5-2-2 American test vehicle. Single stage vehicle consisting of 5 x Recruit + 4 x Algol 1D fired in sequence.|
|Little Joe II|
Credit: © Mark Wade
A preliminary study of a fin-stabilized solid-fuel rocket booster, the Little Joe Senior, was completed by members of STG. The booster would be capable of propelling a full-size Apollo reentry spacecraft to velocities sufficient to match critical portions of the Saturn trajectory. Additional Details: here....
NASA negotiations with NAA on the Apollo spacecraft contract were held at Williamsburg, Va. Nine Technical Panels met on December 11 and 12 to review Part 3, Technical Approach, of the Statement of Work. These Panels reported their recommended changes and unresolved questions to the Technical Subcommittee for action. Later in the negotiations, NASA and NAA representatives agreed on changes intended to clarify the original Statement of Work. Among these was the addition of the boilerplate program. Two distinct types of boilerplates were to be fabricated: those of a simple cold-rolled steel construction for drop impact tests and the more complex models to be used with the Little Joe II and Saturn launch vehicles. The Little Joe II, originally conceived in June 1961, was a solid-fuel rocket booster which would be used to man-rate the launch escape system for the command module.
In addition, the Apollo Project Office, which had been part of the MSC Flight Systems Division, would now report directly to the MSC Director and would be responsible for planning and directing all activities associated with the completion of the Apollo spacecraft project. Primary functions to be performed by the Office would include:
Letter contract No. NAS 9-150, authorizing work on the Apollo development program to begin on January 1, 1962, was signed by NASA and NAA on December 21. Under this contract, NAA was assigned the design and development of the command and service modules, the spacecraft adapter, associated ground support equipment, and spacecraft integration. Formal signing of the contract followed on December 31.
The request for a proposal on the Little Joe II test launch vehicle was submitted to bidders by a letter from MSC, together with a Work Statement. Five launches, which were to test boilerplate models of the Apollo spacecraft command module in abort situations, were called for: three in 1963 and two in 1964. Additional Details: here....
NASA awarded a letter contract to General Dynamics/Convair to design and manufacture the Little Joe II test launch vehicle which would be used to boost the Apollo spacecraft on unmanned suborbital test flights. The Little Joe II would be powered by clustered solid-fuel engines. At the same time, a separate 30-day contract was awarded to Convair to study the control system requirements. White Sands Missile Range, N. Mex., had been selected for the Little Joe II max q abort and high-altitude abort missions.
MSC requested the reprogramming of $100,000 of Fiscal Year 1963 funds for advance design on construction facilities. The funds would be transferred from Launch Operations Center to MSC for use on the Little Joe II program at White Sands Missile Range, N. Mex., and would cover Army Corps of Engineers design work on the launch facility.
NASA and General Dynamics/Convair (GD/C) began contract negotiations on the Little Joe II launch vehicle, which was used to flight-test the Apollo launch escape system. The negotiated cost was nearly $6 million. GD/C had already completed the basic structural design of the vehicle.
NASA issued a definitive contract for $6,322,643 to General Dynamics Convair for the Little Joe II test vehicle. A number of changes defined by contract change proposals were incorporated into the final document:
General Dynamics Convair completed structural assembly of the first launcher for the Little Joe II test program. During the next few weeks, electrical equipment installation, vehicle mating, and checkout were completed. The launcher was then disassembled and delivered to WSMR on April 25, 1963.
Wesley E. Messing, MSC WSMR Operations Manager, notified NASA, North American, and General Dynamics/Convair (GD/C) that Phase I of the range's launch complex was completed. GD/C and North American could now install equipment for the launch of boilerplate 6 and the Little Joe II vehicle.
NASA and General Dynamics/Convair (GD/C) negotiated a second Little Joe II launch vehicle contract. For an additional $337,456, GD/C expanded its program to include the launch of a qualification test vehicle before the scheduled Apollo tests. This called for an accelerated production schedule for the four launch vehicles and their pair of launchers. An additional telemetry system and an instrumentation transmitter system were incorporated in the qualification test vehicle, which was equipped with a simulated payload. At the same time, NASA established earlier launch dates for the first two Apollo Little Joe II missions.
NASA and General Dynamics Convair negotiated a major change on the Little Joe II launch vehicle contract. It provided for two additional launch vehicles which would incorporate the attitude control subsystem (as opposed to the early fixed-fin version). On November 1, MSC announced that the contract amendment was being issued. NASA Headquarters' approval followed a week later.
The Little Joe II qualification test vehicle was launched from White Sands Missile Range, N Mexico. Its objectives were to prove the Little Joe's capability as an Apollo spacecraft test vehicle and to determine base pressures and heating on the missile. These aims were achieved. The lone failure was a malfunction in the destruct system.
NASA and GD/C negotiated amendments totaling $354,737 to Little Joe II contract. This sum covered study activity and several relatively small changes that came out of a Design Engineering Inspection on May 3. More ground support equipment was authorized, as was fabrication of an additional breadboard autopilot system for use at MSC. The dummy payload was deleted and the instrumentation was limited to a control system on the vehicle to be used for Mission A-002 (BP-23).
As a result of wind tunnel tests, Langley Research Center researchers found the LEM Little Joe II configuration to be aerodynamically unstable. To achieve stability, larger booster fins were needed. However, bigger fins caused more drag, shortening the length of the flight. MSC was investigating the possibility of using more powerful rocket engines to overcome this performance degradation.
NASA completed formal negotiations with Aerojet-General Corporation for 12 Algol 1-D solid rocket motors, to be used in the Little Joe II vehicles. The contract was a fixed-price-plus-incentive-fee type with a target price of about $1.4 million. A maximum price of 20 percent more than the target cost was allowed.
Boilerplate 23, Mission A-002, was successfully launched from WSMR by a Little Joe II launch vehicle. The test was to demonstrate satisfactory launch escape vehicle performance utilizing the canard subsystem and boost protective cover, and to verify the abort capability in the maximum dynamic pressure region with conditions approximating emergency detection subsystem limits.
During the flight of boilerplate (BP) 23, the Little Joe II's control system had coupled with the first lateral bending mode of the vehicle. To ensure against any recurrence of this problem on the forthcoming flight of BP-22, MSC asked North American to submit their latest figures on the stiffness of the spacecraft and its escape tower. These data would be used to compute the first bending mode of BP-22 and its launch vehicle.
R. Wayne Young was appointed Chief of the LEM Contract Engineering Branch, ASPO, to perform the functions of Project Officer for the LEM, effective May 3. At the same time M. E. Dell was appointed Chief of the G&N/ACE Contract Engineering Branch, ASPO, and would be responsible for all functions of Project Officer for the guidance and navigation, automatic checkout equipment-spacecraft, and Little Joe II systems for the Apollo spacecraft, and for technical management of the General Electric Support Contract.
A Little Joe II failure investigation presentation was made at MSC July 13 in which General Dynamics/ Convair (GD/C) and MSC's Engineering and Development (E&D) Directorate presented results of independent failure investigations of the mishap which occurred during Apollo Mission A-003 (Boilerplate 22) on June 22, 1965, at WSMR. Additional Details: here....
Little Joe II Program Manager Milton A. Silveira suggested to ASPO Manager Joseph F. Shea that if the next Little Joe II flight test was successful there would be no further requirement for the Little Joe II to support the Apollo program. Silveira said planning had been made with General Dynamics Convair to store the remaining three vehicles, parts, and tooling for one year in case a new requirement from ASPO or NASA should develop. The additional cost of one-year storage compared to normal program closeout was estimated to be small. ASPO concurred with the suggestion on December 1.
KSC proposed to MSC Director Robert R. Gilruth that the two General Electric Co. efforts at KSC supporting automatic checkout equipment (ACE) for spacecraft operations be consolidated. KSC pointed out there was a supplemental agreement with MSC for General Electric to provide system engineering support to ACE/spacecraft operations. Both the KSC Apollo Program Manager and the Director of Launch Operations considered that merging the two GE efforts into a single task order under KSC administrative control would have advantages. The proposal listed two: