It is often forgotten how much many of the new crewed space capsules currently under development in the US owe to the work done as part of NASA’s Apollo program. What is all the more amazing is that the test flights of Apollo hardware upon which these new projects depend had started over half a century ago during the heyday of America’s nascent space program.

The first flight of Apollo hardware was actually a pad abort test, designated PA-1, which took place on November 7, 1963 at the White Sands Missile Range (WSMR) in New Mexico.  Like many of the early test flights, inexpensive and adaptable boilerplate models were employed. Boilerplate models mimic the mass, shape and dynamic properties of flight models but otherwise only carried systems and instruments needed for the tests being conducted. Their low costs and adaptability make them ideal for early testing of a new spacecraft design. For PA-1, the Apollo Launch Escape System (LES) lifted Command Module (CM) BP-6 (Boilerplate #6) in a simulated pad abort. The LES worked as intended lifting BP-6 to a peak altitude of 1.6 kilometers and 1.38 kilometers downrange – slightly higher and farther than predicted.

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The first Apollo pad abort test, PA-1, successfully flown on November 7, 1963 using the BP-6 boilerplate Apollo CM. (NASA)

In order to test Apollo hardware under more stressing conditions that it would experience during an abort situation at higher altitudes and velocities, a launch vehicle of some sort was needed. In this case, NASA used the Little Joe II. The original Little Joe was developed to perform abort tests in support of the Mercury program starting in 1959 (see “Giving Mercury Its Wings: The First Test Flights of NASA’s Mercury Program“). The Little Joe was meant to be a simple, adaptable and inexpensive launch vehicle that would employ various combinations of readily available solid rocket motors firing together or in a preplanned sequence to lift a test capsule to a desired speed and altitude to test the LES under a range of abort situations. On May 11, 1962, the Convair Division of General Dynamics got the contract to develop and build the larger Little Joe II to support the Apollo program.

Diagram showing the typical configuration of the Apollo-Little Joe II. Click on image to enlarge. (NASA)

The Little Joe II was a fin-stabilized rocket with the same 3.96-meter diameter as the simulated Apollo CM it was to lift. With the Apollo CM/LES in place, the Apollo-Little Joe II had a total height of 26.2 meters. The internal configuration of the Little Joe II allowed up to seven Aerojet General Algol 1D solid rocket motors to be carried with each producing 465 kilonewtons of thrust for 40 seconds.  Similar Algol motors were used as the first stage in NASA’s Scout all-solid launch vehicle. Up to six smaller Recruit solid motors could also be carried to provide a 1.5 second kick to aid in liftoff. By varying the number and firing sequence of all these motors, a large range of abort situations could be simulated to altitudes as great as 60,900 meters, although none of the Apollo abort tests would actually fly that high.

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Diagram showing the events of a typical Apollo-Little Joe II abort test flight. Click on image to enlarge. (NASA)

A typical test would have the Little Joe II lift the CM/LES combination to a desired altitude and velocity at which point the LES would pull the CM away from the rocket to perform the abort test and subsequent recovery sequence. WSMR was chosen as the launch site for the abort tests because of the increasingly busy schedule at Cape Canaveral hampered abort test scheduling.  In addition, land recoveries were easier to perform and less expensive than water recoveries.

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Apollo CM boilerplate BP-12 and its LES being prepared for flight at White Sands, NM. (NASA)

The first flight of Apollo hardware on the Little Joe II took place on May 13, 1964. The objectives for this mission, designated A-001, were to determine the aerodynamic characteristics of the LES and verify that it is capable of safely pulling the CM away from an ascending launch vehicle at transonic speeds and high dynamic pressure. Secondary objectives included verifying the overall structural integrity of the CM as well as demonstrate a successful parachute recovery of the BP-12 boilerplate CM. For this flight, the Little Joe II employed a single Algol rocket motor ignited at liftoff. With six smaller Recruit motors also ignited to provide extra liftoff thrust, the A-001 craft had a total launch mass of 26,281 kilograms. This would be the least powerful and lightest Little Joe II configuration flown in the Apollo abort test program.

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Launch of BP-12 on the A-001 test flight from Pad 36 at the White Sands Missile Range on May 13, 1964. (NASA)

The A-001 test flight lifted off at 5:59 MST from Pad 36 at WSMR. Thrust from the single Algol motor was terminated on ground command by rupturing the motor case and, 44 seconds into the flight, the LES fired pulling BP-12 clear. The boilerplate CM, whose aft heat shield was slightly damaged by recontact with the Little Joe II after thrust termination, reached a peak altitude of 9,080 meters before descending back to Earth. The landing sequence proceeded normally until the deployment of the three main parachutes. A riser on one of the parachutes was damaged as a resulting of coming in contact with one of the boilerplate CM’s simulated reaction control motors during deployment. The damaged parachute was cut loose and BP-12 came down on just two parachutes landing 5 minutes and 50 seconds after launch at a speed of 7.9 meters per second – 0.6 meters per second faster than planned but well within human tolerance.

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BP-12 after its successful landing in the desert. (NASA)

Despite the parachute failure, all of the primary test objectives of this flight were met as well as two out of the three secondary objectives. It also turned into an unintended test of the CM’s ability to land safely in case of a parachute failure – a deliberately designed safety feature of the Apollo CM that was actually used in 1971 during the landing of Apollo 15 which experienced a parachute failure during recovery. Three more Apollo-Little Joe II flights and another pad abort test would be flown over the course of the next 20 months to ensure that the LES system could safely operate in the unlikely event of a launch abort (see “The First Launch of Apollo Flight Hardware“).  And for those who are interested, BP-12 is now on display at the Columbia Memorial Space Center in Downey, California.

 

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Related Video

Here is a NASA film about the Apollo A-001 launch abort test.

 

Related Reading

“A Brief History of Launch Aborts”, Drew Ex Machina, November 18, 2014 [Post]

“The First Apollo Orbital Test Flight”, Drew Ex Machina, May 28, 2014 [Post]

 

General References

David Baker, The Rocket: The History and Development of Rocket & Missile Technology, Crown, 1978

Courtney G. Brooks, James M. Grimwood and Loyd D. Swenson, Jr., Chariots for Apollo: A History of Manned Lunar Spacecraft, SP-4205, NASA, 1979

Mary Louise Morse and Jean Kernahan Bays, The Apollo Spacecraft – A Chronology Volume II, SP-4009, NASA

Neil A. Townsend, “Apollo Experience Report – Launch Escape Propulsion Subsystem”, NASA Technical Note D-7083, March 1973