Aerojet/UTC PWN-9 Kangaroo
In the late 1960s, the Space General Division of Aerojet General Corp. designed the Kangaroo rocket. This was a meteorological sounding rocket of the "boosted dart" type, where the dart was nested inside the propellant bore of the booster rocket. This made the Kangaroo significantly more compact (for a given performance) than the contemporary Loki-Dart type rockets (see RM-82/PWN-1, RM-88/PWN-5 and PWN-8) where the dart was mounted on top of the booster. A pyrotechnic charge in the base of the Kangaroo dart was to push it through the motor casing after rocket burnout. The booster's nose cap was to be built of a special glass, which had a high structural strength but would shatter in tiny pieces when hit at the center point. The Kangaroo's design also had the potential advantage of exposing the dart to much less aero- and thermodynamic stress than in the "conventional" boosted dart probes.
The U.S. Navy's Naval Surface Weapons Center at Oxnard became interested in the Kangaroo design, and in July 1968, the designation XPWN-9A was reserved for the projected sounding rocket. However, there was very little development funding available, and the Navy requested competitive bids from the industry. Aerojet's proposal was underbid by the Chemical Systems Division of UTC (United Technology Corp), and in November 1969 UTC got the contract although their proposal was judged inferior in the technical aspect. UTC's dart ejection design was different from Aerojet's and didn't use the special glass head cap on the booster.
|Drawing: Jane's, via Dan Meyer
The Kangaroo was to be used by the Navy's Pacific Missile Range (PMR) at Point Mugu. It was to be launched prior to manned spacecraft to measure cosmic and solar radiation levels as well as micrometeorite density in the high atmosphere and near-earth space. Fired from a simple rail launcher, the apogee of the instrumented dart was to be more than 122 km (400000 ft). The XPWN-9A booster was eventually flight-tested, but the tests were reportedly not successful (possibly because of pitch/roll coupling difficulties). In the end no operational Kangaroo sounding rockets were built.
Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!
Data for XPWN-9A:
|3.05 m (10 ft); dart: 1.22 m (4 ft)
|Booster: 16.5 cm (6.5 in); dart: 4.1 cm (1.6 in)
|> 122 km (76 miles; 400000 ft)
 John W.R. Taylor (ed.): "Jane's all the World's Aircraft 1970-71", Jane's, 1970
 E-mail from Dan Meyer
 Department of Defense Missile Nomenclature Records
Last Updated: 31 August 2003