Applied Physics Lab RTV-N-6 Bumblebee XPM
The primary goal of the U.S. Navy's Bumblebee missile program (see also article on SAM-N-6/RIM-8 Talos) was to develop a ramjet-powered surface-to-air missile. Bumblebee was begun in 1944, and the Applied Physics Lab (APL) of the John Hopkins University initially developed several test vehicles for research on missile propulsion, launching and guidance principles.
The final test missile before the actual XSAM-N-6 tactical missile prototypes was the RTV-6 (RTV-N-6 from early 1948) XPM (Experimental Prototype Missile). The XPM was used to test the overall aerodynamic and propulsion configuration of the SAM-N-6/RIM-8 Talos. As such, the RTV-N-6 used a single solid-fueled rocket booster in the tail, and had a single integral ramjet in a fuselage with cruciform wings and fins. However, individual XPM vehicles slightly differed in their exact characteristics, because of detail differences in the tested configurations. Later XPM models also incorporated the beam-riding guidance system.
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| Drawing: NACA |
| RTV-N-6a (early configuration) * |
Flight tests of the XPM began in 1949, but problems with the booster design led to the disintegration of the first two RTV-N-6a rockets after a few seconds of flight. The first fully successful flight of an XPM representing the Talos configuration was by an RTV-N-6a3 in 1951, and in late 1952, the RTV-N-6a4 successfully intercepted an aerial target. Development and flight tests then proceeded with the XSAM-N-6 Talos.
Specifications
Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!
Data for RTV-N-6a (early configuration):
| Length (w/o booster) | 6.15 m (20 ft 2 in) |
| Wingspan | 2.49 m (8 ft 2 in) |
| Finspan | 2.31 m (7 ft 7 in) |
| Diameter | 71 cm (28 in) |
| Speed | > Mach 2 |
| Ceiling | > 9000 m (30000 ft) |
| Range | > 46 km (25 nm) |
| Propulsion | Sustainer: 24" ramjet; booster: solid-fueled rocket |
Main Sources
[1] James N. Gibson: "Nuclear Weapons of the United States", Schiffer Publishing Ltd, 1996
[2] Norman Friedman: "US Naval Weapons", Conway Maritime Press, 1983
[3] Bill Gunston: "The Illustrated Encyclopedia of Rockets and Missiles", Salamander Books Ltd, 1979
[4] Warren E. Nelson: "Wind-Tunnel Investigation
of a 1/6-Scale Model of the Bumblebee XPM Missile at High Subsonic Speeds", NACA Report RM-A50I11, 1950
Back to Directory of U.S. Military Rockets and Missiles, Appendix 1
Last Updated: 23 January 2003