Encyclopedia Astronautica
SRAM



m131.jpg
SRAM-2
Credit: via Andreas Parsch
American Short Range Attack Missile, an air-launched nuclear-armed solid-propellant stand-off weapon to allow B-52 and FB-111 bombers to penetrate Soviet air space. In service 1972-1990. Retired after the collapse of the Soviet Union.

After cancellation of the Skybolt in 1962, the Air Force still had a need for a stand-off missile for its B-52 strategic bombers. It was not believed the subsonic bomber with its high radar signature could penetrate Soviet Air defenses without such a weapon. Only two of the large interim Hound Dog weapon could be carried per B-52, not enough to get the bomber through. In March 1964, SOR-212 was issued defining a requirement for a short-range attack missile, and development was approved in March 1965 for development of WS-140A. Boeing received the development contract in October 1966. First powered flight was in July 1969, and in August 1972 SRAM began replacing the Hound Dog on B-52s. Production was completed in 1975. Problems with the storage life of the missile's solid rocket motor remained a concern throughout its life. With the end of the Cold War, SRAM was retired in June 1990, and the replacement SRAM II was cancelled a year later without reaching production.

SRAM, like the cancelled Skybolt, was a two-stage, solid propellant, air-to-surface ballistic missile. Armed with a 200 kT W-69 thermonuclear warhead, the missile was much smaller than Skybolt and had only one tenth the range. The first stage accelerated the missile to Mach 3, after which it coasted until approaching the target. Then the second stage would ignite, accelerating the missile until the nuclear warhead was detonated over the target. Various profiles could be flown depending on the air defenses to penetrated, so the range would be anything from 55 km (35 miles) for low-altitude profiles to 160 km (100 miles) for high-altitude profiles. Inertial guidance made the missile autonomous, and a radar altimeter allowed the missile to fly nap-of-the-earth profiles under Soviet radar. A B-52 normally carried 8 SRAMs on a rotary launcher in the bomb bay, but up to 12 more could be fitted on two external 6-missile pylons. The FB-111A medium bomber carried up to 6 SRAMs.

Failures: 1. Success Rate: 96.77%. First Fail Date: 1974-08-20. Last Fail Date: 1974-08-20. Launch data is: complete. Development Cost $: 450.600 million. Recurring Price $: 0.466 million in 1974 dollars. Flyaway Unit Cost $: 0.267 million in 1974 dollars. Maximum range: 190 km (110 mi). Number Standard Warheads: 1. Standard warhead: W69. Warhead yield: 170 KT. Boost Propulsion: Solid rocket. Maximum speed: 3,710 kph (2,300 mph). Initial Operational Capability: 1972. Total Number Built: 1541. Total Development Built: 41. Total Production Built: 1500.

Historical Essay © Andreas Parsch

Boeing AGM-69 SRAM

The SRAM (Short Range Attack Missile) was a relatively small standoff missile for use by USAF's B-52 and FB-111A strategic bombers. On the B-52, it replaced the AGM-28 Hound Dog.

After the cancellation of the GAM-87-AGM-48 Skybolt ALBM (Air-Launched Ballistic Missile) in December 1962, the USAF had to find another way to modernize the strike capabilities of its strategic bomber force. In March 1964, SOR (Specific Operational Requirement) 212 for a short-range attack missile was submitted by the USAF, and in March 1965, development was approved by the Department of Defense. SRAM was known as WS (Weapon System) 140A, and the missile designator ZAGM-69A was assigned. The following design competition was won by Boeing, who received a development contract for the SRAM in October 1966. The SRAM was to be used by the B-52, the FB-111A, and the then forthcoming AMSA (Advanced Manned Strategic Aircraft, later designated as B-1). The first powered flight of an AGM-69A occurred in July 1969, and in January 1971, full scale production of the SRAM was approved. In August 1972, the SRAM was operational with SAC units, and quickly replaced the AGM-28 Hound Dog as the B-52's standoff attack missile.

The AGM-69A was a ballistic-type air-to-ground missile powered by a Lockheed SR75-LP-1 two-stage solid-fuel rocket motor, and armed with a 200 kT W-69 thermonuclear warhead. The first motor stage propelled the missile to Mach 3 after launch, and the second stage was ignited near the target for a powered terminal approach. Maximum range varied from 55 km (35 miles) for low-altitude launches to 160 km (100 miles) for high-altitude firings. The SRAM was guided by an General Precision-Kearfott KT-76 inertial navigation system, assisted by a Stewart-Warner terrain clearance sensor, and could achieve an accuracy of about 430 m (1400 ft) CEP. The B-52 Stratofortress could carry 8 SRAMs on a rotary launcher in the bomb bay, and up to 12 more on two external 6-missile pylons. The FB-111A could carry up to 6 SRAMs. When carried externally, an expendable tail faring was used on the missile to reduce drag. The AGM-69A greatly increased the number of targets which could be attacked by a single bomber, and made it possible to attack known (fixed) air-defense installations en route to the primary target.

Several proposals were made to improve the versatility of the AGM-69A, including a radar guidance system to use it as an air-to-air missile, or an anti-radiation seeker to attack mobile air-defense radars, but none of these features were adopted. In the mid-1970s, however, storability problems with the rocket motor surfaced, and in 1976 Thiokol was awarded a contract to develop a new motor for SRAM. In 1977, the new motor was combined with other upgrades, including an improved guidance system (with enhanced computing capability) and the W-80 warhead of the AGM-86 ALCM. The new SRAM missile, designated AGM-69B SRAM B, was intended for use by the B-1A. In 1978, however, the B-1A was cancelled, and the USAF found a way to extend the lifespan of the old motor to the originally planned 5 years, and these two events killed the AGM-69B program. Instead, it was then planned to eventually replace the AGM-69A with the AGM-86 ALCM and the forthcoming ASALM (Advanced Strategic Air-Launched Missile). The latter, however, was also cancelled in 1980. When the B-1 program was resurrected (as B-1B) in 1981, it was decided to develop an entirely new weapon, later to be known as AGM-131 SRAM II.

In June 1990, the AGM-69A SRAM was retired from the USAF inventory. Various reasons have been quoted, including unreliability of the warhead and the rocket motor. The AGM-131 SRAM II was cancelled the following year, leaving effectively a gap in the capability of the USAF's B-52 bomber force. A total of about 1500 AGM-69A missiles were built by Boeing until production ended in 1975.

Specifications

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

Data for AGM-69A:

Length 4.27 m (14 ft) (4.83 m (15 ft 10 in) with tail fairing)
Fin Halfspan 38 cm (15 in) (fin tip to centerline)
Diameter 45 cm (17.5 in)
Weight 1010 kg (2230 lb)
Speed Mach 3
Range 160 km (100 miles)
Propulsion Lockheed Propulsion Co. SR75-LP-1 two-stage solid-fueled rocket
Warhead W-69 thermonuclear (200 kT)
Main Sources

[1] James N. Gibson: "Nuclear Weapons of the United States", Schiffer Publishing Ltd, 1996
[2] Bill Gunston: "The Illustrated Encyclopedia of Rockets and Missiles", Salamander Books Ltd, 1979
[3] Christopher Chant: "World Encyclopaedia of Modern Air Weapons", Patrick Stephens Ltd., 1988


AKA: WS 140A; AGM-69A; SRAM.
Status: Retired 1983.
Gross mass: 1,016 kg (2,239 lb).
Height: 4.82 m (15.81 ft).
Diameter: 0.45 m (1.47 ft).
Span: 0.61 m (2.00 ft).
Apogee: 10 km (6 mi).
First Launch: 1974.08.20.
Last Launch: 1983.07.26.
Number: 31 .

More... - Chronology...


Associated Countries
Associated Engines
  • SR75 Lockheed solid rocket engine. SRAM AGM-69, ASAT ASM-135. More...

See also
  • SRAM Short Range Attack Missile, a relatively small standoff missile for use by USAF's B-52 and FB-111A strategic bombers. More...
  • missile Guided self-propelled military weapon (as opposed to rocket, an unguided self-propelled weapon). More...

Associated Manufacturers and Agencies
  • Boeing American manufacturer of rockets, spacecraft, and rocket engines. Boeing Aerospace, Seattle, USA. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • Parsch, Andreas, DesignationSystems.Net, Web Address when accessed: here.

Associated Launch Sites
  • Grand Turk Island DZ Rocket air-launch position known to have been used for 7 launches from 1976 to 1978, reaching up to 10 kilometers altitude. More...

Associated Stages
  • SRAM-1 Solid propellant rocket stage. Loaded mass 1,000 kg. More...

SRAM Chronology


1974 August 20 - . 11:09 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM. FAILURE: Failure.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1975 March 25 - . 12:01 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1975 April 21 - . 12:35 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1975 May 12 - . 11:24 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1975 May 12 - . 11:54 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1975 May 23 - . 11:35 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1975 May 23 - . 11:58 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1975 November 13 - . 13:16 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1975 November 14 - . 12:30 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1975 November 24 - . 13:15 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1976 April 14 - . 12:01 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1976 April 14 - . 12:21 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1976 December 14 - . 12:00 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: 21.0 N x 70.0 W. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF SAC. Apogee: 10 km (6 mi).

1976 December 14 - . 12:20 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: 21.0 N x 70.0 W. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF SAC. Apogee: 10 km (6 mi).

1977 April 14 - . 11:59 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: 21.0 N x 70.0 W. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM. LV Configuration: SRAM Case 29.
  • Test mission - . Nation: USA. Agency: USAF SAC. Apogee: 10 km (6 mi).

1977 December 14 - . 12:54 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: 21.0 N x 70.0 W. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM. LV Configuration: SRAM Case 33.
  • Test mission - . Nation: USA. Agency: USAF SAC. Apogee: 10 km (6 mi).

1978 March 1 - . 12:00 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: 21.0 N x 70.0 W. Launch Platform: B-52G. LV Family: SRAM. Launch Vehicle: SRAM. LV Configuration: SRAM Case 34.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1978 July 20 - . 11:49 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: 21.0 N x 70.0 W. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM. LV Configuration: SRAM Case 30.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1978 December 13 - . 11:58 GMT - . Launch Site: Grand Turk Island DZ. Launch Pad: 21.0 N x 70.0 W. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM. LV Configuration: SRAM Case 33.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1979 January 17 - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1979 January 19 - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1979 January 19 - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1979 February 7 - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1979 November 28 - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1979 December 12 - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1979 December 12 - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1980 February 6 - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1980 November 5 - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1981 December 9 - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: FB-111. LV Family: SRAM. Launch Vehicle: SRAM. LV Configuration: SRAM Case 85.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1983 June 22 - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

1983 July 26 - . Launch Site: Grand Turk Island DZ. Launch Pad: Aircraft from Cape Canaveral. Launch Platform: B-52. LV Family: SRAM. Launch Vehicle: SRAM.
  • Test mission - . Nation: USA. Agency: USAF. Apogee: 10 km (6 mi).

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