University of Michigan/NACA PWN-3 Nike-Cajun (original) (raw)
In the early 1950s, the standard sounding rocket for high-altitude research was the Aerobee (for details, seeXRM-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 theSAM-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.
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.
Specifications
Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!
Data for PWN-3A:
| Length | 7.70 m (25 ft 3 in) |
|---|---|
| Diameter | 1st stage: 41.9 cm (16.5 in); 2nd stage: 16.5 cm (6.5 in) |
| Finspan | 1st stage: 1.51 m (59.5 in); 2nd stage: 0.63 m (25 in) |
| Weight | 700 kg (1550 lb) |
| Speed | 6760 km/h (4200 mph) |
| Ceiling | > 160 km (100 miles) |
| Propulsion | 1st stage: Allegheny Ballistics Lab. X216A2 solid-fueled rocket; 246 kN (55000 lb) for 3 s2nd 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