Directory of U.S. Military Rockets and Missiles
Copyright © 2002 Andreas Parsch

University of Michigan/NACA RM-85/PWN-3 Nike-Cajun

In the early 1950s, the standard sounding rocket for high-altitude research was the Aerobee (for details, see XRM-84/PWN-2 Aerobee-Hi). However, this liquid-fueled rocket was relatively expensive and complicated to operate. Therefore various research agencies searched for simpler and cheaper rockets for routine high-altitude soundings and scientific experiments. One solution was to combine existing rocket boosters into multi-stage rockets, and the most important first stage motor for these applications was the M5 (X216A2) booster of the SAM-A-7/MIM-3 Nike Ajax anti-aircraft missile.

Following successful tests with Nike-Deacon combinations, the University of Michigan and the NACA developed a rocket with a more efficient upper stage under contract from the Air Force Cambridge Research Center (AFCRC). The result was the Thiokol TE-82 Cajun rocket, which was essentially a Deacon with an improved propellant. The first launch of a Nike-Cajun (also known as CAN for "Cajun And Nike") occurred in July 1956. The Nike booster was equipped with four instead of the normal three stabilizing fins. The Nike-Cajun could carry a payload between 4.5 kg (10 lb) and 45 kg (100lb), depending on the altitude requirement. A wide variety of payloads has been launched on Nike-Cajun rockets, including general upper atmosphere experiments, magnetic field experiments, horizon photography to obtain weather data, ionosphere experiments and astronomy payloads.

Photo: Sven Knudson, Ninfinger Productions
Nike-Cajun (PWN-3A)

In April 1959, the USAF allocated the formal research missile designation XRM-85 to the Nike-Cajun rocket at the request of the AFCRC, and in June 1963 this designation was changed to PWN-3A. Air Force use of the XRM-85/PWN-3A was limited, however, and probably ended in the mid-1960s. The Nike-Cajun was a very successful general purpose sounding rocket, and the last flight was launched by NASA in October 1976.


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

Data for PWN-3A:

Length7.70 m (25 ft 3 in)
Diameter1st stage: 41.9 cm (16.5 in); 2nd stage: 16.5 cm (6.5 in)
Finspan1st stage: 1.51 m (59.5 in); 2nd stage: 0.63 m (25 in)
Weight700 kg (1550 lb)
Speed6760 km/h (4200 mph)
Ceiling> 160 km (100 miles)
Propulsion1st stage: Allegheny Ballistics Lab. X216A2 solid-fueled rocket; 246 kN (55000 lb) for 3 s
2nd stage: Thiokol TE-82-1 Cajun solid-fueled rocket; 37 kN (8300 lb) for 2.8 s

Main Sources

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

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Last Updated: 27 October 2002