Directory of U.S. Military Rockets and Missiles|
Appendix 4: Undesignated Vehicles
|Copyright © 2003-2009 Andreas Parsch|
The HGV (Hypersonic Glide Vehicle) was a U.S. Air Force program for a hypersonic aero-ballistic (boost/glide) ground attack missile. It is still classified, and therefore undisputed information, including whether any HGVs were built at all, is almost non-existing. The HGV project was probably begun in the early 1980s. The contractor who is usually credited with actually building the HGV is the Lockheed Missiles and Space Company.
No HGV construction, let alone flight test, was ever openly announced. However, it is reported that several tests occurred in the 1990/93 time frame, possibly under the program name HAVE SPACE. The HGV was carried to 20000 m (68000 ft) under the wing of a modified B-52H, and after release a large rocket booster accelerated the missile to Mach 18. In the long hypersonic glide after booster separation, the HGV could cover up to 8000 km (5000 miles). It's possible that the HGV test missiles were recoverable. The exact configuration of the HGV remains unconfirmed, but reports point towards a highly-swept (75°) delta planform and four vertical tails. Thermal protection was provided by a carbon-carbon composite skin (similar to the Space Shuttle leading edges) on a titanium structure. The HGV would have used guidance technology developed under the USAF's MaRV (Manoeuvering Reentry Vehicle) program.
|Image: via Stéphane Cochin, Stratosphere Models|
|HGV (possible configuration)|
The USAF planned to develop the HGV as a survivable quick reaction nuclear strike weapon with a payload of two or three nuclear warheads. Its high speed (Mach 5+ over the target) and relatively shallow approach trajectory would have given a potential target an extremely short reaction time (much less than in an ICBM attack), making attacks against e.g. mobile ICBM launchers possible. A variant of the HGV, known as Strategic Boost Glide Vehicle, was to be launched from the top of a modified LGM-30 Minuteman ICBM, for a total range of 15000 km (9300 miles). In the end, no operational HGV missiles were built, most likely because the end of the Cold War made such advanced strategic weapon systems unnecessary.
Note: Data given by several unconfirmed sources show variations. Figures given below may therefore be inaccurate!
Data for HGV:
|Length (incl. booster)||14 m (46 ft); w/o booster: 9 m (30 ft)|
|Wingspan||3.4 m (11 ft 2 in)|
|Weight||11300 kg (25000 lb)|
|Range (air launch)||8000 km (5000 miles)|
|Propulsion||Rocket booster (HGV itself unpowered)|
|Warhead||2x or 3x thermonuclear|
 Bill Sweetman: "Aurora, The Pentagon's Secret Hypersonic Spyplane", Motorbooks Intl., 1993
 Mark Wade: Encyclopedia Astronautica
Back to Directory of U.S. Military Rockets and Missiles, Appendix 4