Directory of U.S. Military Rockets and Missiles
Appendix 4: Undesignated Vehicles
Copyright © 2004 Andreas Parsch

JPL (GALCIT) Private

In World War 2, the Guggenheim Aeronautical Laboratory of the California Institute of Technology (GALCIT) began a rocket development program. The initial result was a reliable solid-propellant JATO (Jet-Assisted Take-Off) rocket, and in 1944, GALCIT proposed a long-term development program for ballistic missiles to Army Ordnance. The first test vehicle of the program was the Private A, which was test-flown by GALCIT in December 1944.

The Private A was a very simple unguided ballistic rocket, whose main purpose was to test a fin-stablized rocket in free flight. The rocket itself was a standard JATO unit, which was fitted with four rectangular tail fins in a cruciform arrangement. Because of the slow-burning JATO rocket, the vehicle was equipped with a booster assembly consisting of four T-22 artillery rockets. The Private A was launched from a small tower with guide rails to keep it stable until enough velocity was reached for the fins to be effective. The booster assembly was jettisoned when the rocket left the launcher.

Photo: via Peter Alway
Private A

GALCIT fired 24 Private As between 1 December and 16 December 1944. Far from all flights were successful, but the basic principle of a fin-stabilized ballistic rocket was verified. The Private A could fly a maximum distance of about 18300 m (20000 yds) after a flight of about 90 seconds.

In January 1945, the Army finally officially agreed to fund GALCITs ballistic rocket program, which thus became known as the ORDCIT (Ordnance/CIT) program. At about the same time, GALCIT's rocket group adopted the name Jet Propulsion Laboratory (JPL).

Photo: U.S. Army
Private F

After the Private A, JPL built the Private F rocket. This was essentially a Private A, where the cruciform tail fins were replaced by a single vertical fin and two larger wings. Two small forward horizontal fins were added for trimming. Private F's booster assembly was the same as that of the earlier rocket. Between 1 April and 13 April 1945, 17 Private F rockets were fired. However, the rocket proved to be unstable in free flight, and the tests showed that a winged missile would need some kind of active control system (i.e. an autopilot).

Photo: U.S. Army
Private F

In the long term, the ORDCIT program led directly to the first operational ballistic missile of the U.S. Army, the SSM-A-17/MGM-5 Corporal.


Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!

Data for Private A/F:

 Private APrivate F
Lengthwithout booster: 2.34 m (7 ft 8 in)
incl. booster: 3.38 m (11 ft 1 in)
Wingspan0.86 m (2 ft 10 in)1.5 m (5 ft)
Nose fin spann/a0.76 m (2 ft 6 in)
Diameter (main body)24.4 cm (9.6 in)
Weight (w/o booster)240 kg (529 lb)230 kg (506 lb)
Speed400 m/s (1300 ft/s)365 m/s (1200 ft/s)
Range18300 m (20000 yds)4600 m (5000 yds)
PropulsionBooster: 4x T-22 solid-propellant rocket; 24.5 kN (5500 lb) each for 0.2 s
Sustainer: Solid-propellant rocket; 4.4 kN (1000 lb) for 30 s

Main Sources

[1] "Ordnance Department Guided Missile Program", U.S. Army, 1948
[2] Peter Alway: "Rockets of the World, 1999 Supplement", Saturn Press, 1999
[3] Norman J. Bowman: "The Handbook of Rockets and Guided Missiles", Perastadion Press, 1963
[4] Frederick I. Ordway III, Ronald C. Wakeford: "International Missile and Spacecraft Guide", McGraw-Hill, 1960

Back to Directory of U.S. Military Rockets and Missiles, Appendix 4

Last Updated: 8 September 2004