Directory of U.S. Military Rockets and Missiles|
Appendix 4: Undesignated Vehicles
|Copyright © 2003 Andreas Parsch|
In 1976, the U.S. Air Force issued a requirement for a new air-launched missile called ASALM (Advanced Strategic Air-Launched Missile). ASALM was intended as a nuclear-armed replacement for the AGM-69 SRAM (Short-Range Attack Missile) with a longer range and a much higher speed. Apart from its primary strategic air-to-ground mission, the missile was planned to have a secondary air-to-air role against AWACS (Airborne Warning And Control System) aircraft coordinating the enemy's air defenses. ASALM would have used inertial guidance in the cruise phase, and would have been equipped with a dual-mode seeker for terminal guidance against ground or air targets. The missile was to be of the same size as the SRAM so that it could be used from the same launchers. Two airframe/propulsion teams competed for the ASALM development contract, these being Martin Marietta/Marquardt and McDonnell Douglas/UTC.
|ASALM (Martin Marietta design)|
The major innovation in ASALM was the integrated rocket/ramjet propulsion system. A solid-fueled rocket motor accelerated the missile to supersonic speed, when the now empty rocket casing served as the combustion chamber for the ramjet sustainer. Before ramjet ignition, an aerodynamic cover on the ramjet intake and the rocket nozzle were ejected. Between October 1979 and May 1980, seven flight tests of propulsion technology validation (PTV) vehicles were successfully conducted. These PTV vehicles were probably closely related to the Marquardt LASRM (Low-Altitude Short Range Missile), which reportedly tested integrated rocket/ramjet technology under Air Force program 655A. In one of the PTV tests, the missile accidentally accelerated beyond the planned speed, and eventually reached Mach 5.5 at 12200 m (40000 ft)! The planned cruise speed for operational ASALM missions was to be around Mach 4.5 for a range of about 480 km (300 miles).
|ASALM (PTV vehicle)|
ASALM development was put on hold after the completion of the PTV flights in 1980, and later cancelled. I have found no explicit reasons for the cancellation, but it was most likely connected to budget restrictions and the concurrent development of the AGM-86 ALCM (Air-Launched Cruise Missile).
In 1983, Martin Marietta submitted a derivative of its ASALM design as a candidate in the U.S. Navy's YAQM-127A SLAT (Supersonic Low-Altitude Target) competition. The design was eventually selected as winner, but SLAT was cancelled after the initial test phase.
Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!
Data for ASALM:
|Length||4.3 m (14 ft)|
|Range||480 km (300 miles)|
|Propulsion||Marquardt integrated rocket/ramjet|
|Warhead||Thermonuclear (possibly W-69 (200 kT))|
 Bill Gunston: "The Illustrated Encyclopedia of Rockets and Missiles", Salamander Books Ltd, 1979
 R.T. Pretty (ed.): "Jane's Weapon Systems 1982-83", Jane's, 1983
Back to Directory of U.S. Military Rockets and Missiles, Appendix 4