Cutaway drawing of SAINT FSV.
American military anti-satellite system. Cancelled 1963.
Project SAINT (SAtellite INTerceptor) was a large and still deeply classified US Air Force program begun in the late 1950's covering a wide range of technologies for interception, inspection, and destruction of enemy spacecraft. After studies in the 1950's, a development contract was let to Radio Corporation of America at the end of 1960. Saint Phase I would have weighted 1,100 kg and been launched by Atlas D/Agena B. Phase II would have been twice as big and launched by Atlas Centaur. The project was cut back in October 1962 and eventually canceled. The spacecraft would have rendezvoused with hostile satellites and inspected them with television cameras.
The CIA's 1957 National Intelligence Estimate NIE 11-5-57 predicted that the Soviet Union would orbit a photo-reconnaissance satellite by 1963. The US Air Force response was prompt. GOR-170 was issued on 19 June 1958 for development of an anti-satellite weapons system. The Air Force and ARPA commissioned parallel feasibility studies by Space Technology Laboratory (STL) and Radio Corporation of America (RCA). The Air Force plan for SAINT (Satellite Inspector for Space Defense) was presented to the National Security Council on 5 February 1960. After various bureaucratic steps RCA received the contract to develop SAINT on 17 March 1961. The program was to consists of three phases:
- Phase 1 - Demonstration of a prototype spacecraft that could rendezvous with and inspect an unidentified satellite of 1 sq m radar cross-section in an orbit up to 740 km altitude.
- Phase 2 - An automated vehicle that could make multiple orbital changes and rendezvous and inspect satellites up to 1850 to 7400 km altitude
- Phase 3 - An anti-satellite that would not only inspect but destroy enemy satellites
The SAINT system developed by RCA consisted of:
- A ground segment, consisting of a SAINT Operations Center within NORAD's complex at Colorado Springs; launch facilities capable of responding within 12 hours at Cape Canaveral and Vandenberg; and ground stations in Florida and Rhodesia. Once NORAD had determined the orbital parameters of a hostile satellite, the NORAD Commander-in Chief had the authority to launch a SAINT to inspect it.
- A launch vehicle. STL's 1959 study considered use of a Thor-Hydra (Lox/LH2 second stage) booster. But finally the more capable (and available) Atlas-Agena B developed for the CIA's reconnaissance satellite program was selected for Phase 1. Phase 2 would use the more capable Atlas-Centaur.
- The FSV (or Final Stage Vehicle). This was the spacecraft that would close in for the final rendezvous. It was imagined that in the future, more than one FSV would be launched per booster. This autonomous satellite included:
- A powerful pressure-fed storable propellant main engine at the centre line
- A computer and inertial measuring unit to control maneuvers
- A long-range dish radar and close-in ranging radar to guide the satellite to its target. The long range system was an adaptation of the Westinghouse radar used on the Bomarc surface-to-air missile.
- A bank of lights to illuminate the target spacecraft after rendezvous
- Four television cameras to send back views of the satellite
- Tape recorders for recording video and data for downlink when the satellite was over a ground station
- Radiation detectors to determine if the enemy satellite carried nuclear weapons or a radioactive power source
- Infrared sensors to image the target satellite
- Gravimetric sensors to determine the mass of the enemy satellite
- Countermeasures (decoy identification, booby-trap detection, anti-jamming provisions, automatic responses in case of hostile maneuvering by the enemy satellite)
- Nitrogen cold-gas jets for orientation.
The operational concept was for an immediate rendezvous after launch. The Agena B/FSV combination would be placed in an elliptical orbit ahead of the enemy satellite such that the target would be closing with SAINT at 180 m/s. Once the catch-up phase was complete, the Agena would burn to place the SAINT in a co-orbit with the target. SAINT's long range radar would search for the target. Once acquired, the Agena would be jettisoned. Within 8 to 12 minutes SAINT's radar and guidance systems would automatically maneuver the spacecraft until it was stationed 12 m from the target. For a Cape Canaveral launch, this would allow the satellite to provide an initial video and data dump to the ground station in Rhodesia. A full inventory of the target's characteristics would take two hours, and be recorded for relay to a ground station at the first opportunity. SAINT would stay within 60 m of the target for 48 hours, closing repeatedly for imaging and measurements from different angles. After that it would run out of battery power and propellant.
There were to four SAINT development launches, later increased to eight, with the first launch planned for December 1962. However before that could happen, Secretary of Defense McNamara cancelled SAINT and the SAINT-II manned follow-on program. Internal wrangling within the Air Force, the inability of the system to operate in nuclear-war conditions, and the limited number of SAINT's that could be launched at once all factored into the decision.
Several target kill mechanisms were suggested for Phase 3 versions. The spacecraft could just collide with the target or, it was suggested, just spray it with black paint.
By the late 1960's, the idea of rendezvous for inspection of satellites was pretty much abandoned. It could be hazardous to the inspecting vehicle. The Russians from the very beginning installed destruct packages on their military satellites. These would blow up the satellite and anything near it. The sophisticated Russian APO-2 automatic destruct system could be set off by ground control or automatically if it sensed that normal spacecraft operating parameters were exceeded. The task of simply inspecting enemy satellites could be accomplished more safely at long ranges using existing reconnaissance satellites. These could be maneuvered to examine not just ground targets, but other spacecraft as well (as was done on an early shuttle flight to see if there was damage on the belly tiles). Earth-based cameras also were providing very high quality pictures of satellites.
The ASAT role itself, following identification and tracking, could be more cheaply accomplished by sub-orbital interceptors launched from earth. These could hit a satellite in any orbit without warning.
However none of these drawbacks stopped the Soviet Union from developing and operating its own equivalent system from 1969 to 1984…
AKA: SAtellite INTerceptor.
More... - Chronology...
Gross mass: 1,100 kg (2,400 lb).
Associated Launch Vehicles
Atlas The Atlas rocket, originally developed as America's first ICBM, was the basis for most early American space exploration and was that country's most successful medium-lift commercial launch vehicle. It launched America's first astronaut into orbit; the first generations of spy satellites; the first lunar orbiters and landers; the first probes to Venus, Mars, Mercury, Jupiter, and Saturn; and was America's most successful commercial launcher of communications satellites. Its innovative stage-and-a-half and 'balloon tank' design provided the best dry-mass fraction of any launch vehicle ever built. It was retired in 2004 after 576 launches in a 47-year career. More...
Atlas Agena D American orbital launch vehicle. Atlas D with further improved and lightened Agena upper stage. More...
Associated Manufacturers and Agencies
USAF American agency overseeing development of rockets and spacecraft. United States Air Force, USA. More...
RCA American manufacturer of spacecraft. RCA, USA. More...
Golovine, Michael N, Conflict in Space, Temple Press, London, 1962.
Pesavento, Peter, "Russian Space Shuttle Projects 1957-1994", Spaceflight, 1995, Volume 37, page 226.
Day, Dwayne A (Editor), et. al., Eye in the Sky : The Story of the Corona Spy Satellites, Smithsonian Institution Press, 1998.
Federation of American Scientists Web Site, Web Address when accessed: here.
Chun, Clayton K S, "A Falling Star: SAINT, America's First Antisatellite System", Quest, Summer 1998, Volume 6, Number 2, page 44.
1958 June 19 -
- USAF issues requirement for an anti-satellite system - .
Nation: USA. Spacecraft: SAINT; SAINT II. Summary: USAF GOR-170 is issued for a system to inspect and destroy enemy satellites..
December 1959 -
- Public furor as the USAF fails to properly identify unidentified object in space. - .
Nation: USA. Spacecraft: SAINT; SAINT II. Summary: This humilitation led the Air Force to pursue its SAINT ASAT project..
1959 December 21 -
- STL completes study on an anti-satellite systems - .
Nation: USA. Spacecraft: SAINT; SAINT II. Summary: Space Technologies Laboratory completed a USAF-funded feasibility study on the topic..
1960 January 31 -
- RCA completes study on an anti-satellite system - .
Nation: USA. Spacecraft: SAINT; SAINT II. Summary: Radio Corporation of America completes an ARPA-funded feasibility study on the topic..
1960 February 5 -
- US National Security Council briefed on USAF plans for an anti-satellite system. - .
Nation: USA. Spacecraft: SAINT; SAINT II. Summary: Assistant Air Force Secretary Joseph Charyk presented the plan..
1960 April 5 -
- Conditional approval for SAINT development. - .
Nation: USA. Spacecraft: SAINT; SAINT II. As usual, Herbert York, McNamara's Director of Defense, Research, and Engineering, was hostile to the concept. It was approved only on the condition that Gerneral Schriever, Commander of the Air Research and Development Command, fund it from the existing budget by cutting back other programmes.
1960 April 21 -
- SAINT System Development Requirement issued. - .
Nation: USA. Spacecraft: SAINT; SAINT II. Summary: It also allowed follow-on manned systems to be pursued..
1960 July 15 -
- USAF Air Staff approval for SAINT development - .
Nation: USA. Spacecraft: SAINT; SAINT II.
1960 August 23 -
- Final Department of Defense approval for SAINT development. - .
Nation: USA. Spacecraft: SAINT; SAINT II.
1960 November 1 -
- Chelomei R winged manned spacecraft project starts - .
Nation: USSR. Related Persons: Chelomei; Myasishchev; Tsybin. Class: Manned. Type: Manned spaceplane. Spacecraft: Raketoplan; SAINT; SAINT II. Immediately after cancellation of similar projects at Myasishchev and Tsybin bureaus, Chelomei's new bureau is assigned to build equivalent of US Dynasoar / Saint II. Winged manned spacecraft for interception, inspection, and destruction of US satellites up to 290 km altitude. Two man crew, 24 hour mission duration, large aft drag brakes.
1961 March 16 -
- Project SAINT Phase I contract signed by RCA. - .
Nation: USA. Spacecraft: SAINT; SAINT II. Project SAINT (SAtellite INTerceptor) was a large and still deeply classified US Air Force program begun in the late 1950's covering a wide range of technologies for interception, inspection, and destruction of enemy spacecraft. After studies in the 1950’s. The Phase I development contract was let to Radio Corporation of America. Saint Phase I would have weighted 1,100 kg and been launched by Atlas D/Agena B.
1961 May 29 -
- Advanced Re-entry Technology program and SAINT II program. - .
Nation: USA. Spacecraft: Dynasoar; Asset; SAINT; SAINT II. Summary: The Space Systems Division completed two development plans for an Advanced Re-entry Technology program and a SAINT II program..
1962 October -
- Project SAINT cut back. - .
Nation: USA. Spacecraft: SAINT; SAINT II. Summary: Project SAINT satellite interceptor project was cut back, leading to its eventually cancellation. The spacecraft would have rendezvoused with hostile satellites, inspected them with television cameras, and then disabled them..
December 1962 -
- SAINT is cancelled. - .
Nation: USA. Spacecraft: SAINT; SAINT II. Summary: The unmanned SAINT-I and manned SAINT-II anti-satellite systems are cancelled..
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