Directory of U.S. Military Rockets and Missiles
Appendix 4: Undesignated Vehicles
Copyright © 2004-2006 Andreas Parsch

Boeing HIBEX

The HIBEX (High-G Boost Experiment) research missile was built by Boeing for ARPA (Advanced Research Projects Agency) and the U.S. Army Missile Command as part of a project named Defender. It was designed to evaluate technology for very-high acceleration interceptor missiles, like the then planned Sprint short-range anti-ballistic missile.

Photos: White Sands Missile Range Museum

HIBEX had a short conical body and was powered by a solid-propellant rocket motor. Its design goal was the capability to intercept ICBM reentry vehicles at altitudes of less than 6100 m (20000 ft), where the RV would travel at about 3 km/s (10000 fps). The initial acceleration of HIBEX was almost 400 g. At least seven HIBEX rockets were fired at White Sands Missile Range (WSMR) between February 1965 and January 1966, and the test results were used in the development of the operational Sprint missile.

In 1968, DARPA began the UPSTAGE (Upper Stage Acceleration and Guidance Experiment) program, which flight-tested a highly manoeuverable second stage for HIBEX boosters. Between November 1971 and August 1972, five UPSTAGE tests were conducted at the WSMR. The flights evaluated stage separation, guidance & control systems, and structural and aerodynamic properties. Then new laser gyros were used in the guidance and control section, because conventional mechanical ones were too slow for the required reaction time and acceleration. The UPSTAGE stage was a solid-propellant rocket, which weighed about 140 kg (300 lb), and used "finlet" injections for transverse thrust. It was command-guided from the ground, and achieved lateral accelerations of up to 300 g and command response times in the order of milliseconds. This performance would have been necessary to intercept MaRVs (Manoeuvering Reentry Vehicles).


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

Data for HIBEX:

Length4.9 m (16 ft)
Diameter1.1 m (3.6 ft)
Weight1180 kg (2600 lb)
Speed2560 m/s (8400 fps)
PropulsionSolid-fueled rocket; 2180 kN (490000 lb) for 1.1 s

Main Sources

[1] John W.R. Taylor (ed.): "Jane's all the World's Aircraft 1966-67", Jane's, 1966
[2] Richard H. van Atta "DARPA Technical Accomplishments, Volume II: An Historical Review of Selected DARPA Projects", Institute for Defense Analyses, 1991
[3] Mark Paine: Nuclear ABMs of the USA

Back to Directory of U.S. Military Rockets and Missiles, Appendix 4

Last Updated: 13 December 2006