Vanguard (rocket)
Launch of Vanguard rocket. (U.S. Navy)
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| Function | Satellite launch vehicle |
|---|---|
| Manufacturer | Martin |
| Country of origin | United States |
| Size | |
| Height | 23.00 m (75 feet) |
| Diameter | 1.14 m (3.74 feet) |
| Mass | 22,156 lb (10,050 kg) |
| Stages | 3 |
| Capacity | |
| Payload to LEO | 9 kg |
| Launch history | |
| Status | Retired |
| Launch sites | LC-18A, Cape Canaveral |
| Total launches | 11 |
| Successes | 3 |
| Failures | 8 |
| First flight | October 23, 1957 (first orbit Vanguard 1: April 17, 1958) |
| Last flight | September 18, 1959 |
| First stage - Vanguard | |
| Engines | 1 X-405 |
| Thrust | 30,303 lbf (134.79 kN) |
| Specific impulse | 248 seconds |
| Burn time | 2 min 25 s |
| Fuel | LOX/kerosene |
| Second stage - Delta | |
| Engines | 1 AJ10-37 |
| Thrust | 7,599 lbf (33.80 kN) |
| Specific impulse | 261 seconds |
| Burn time | 1 min 55 s |
| Fuel | Nitric acid/UDMH |
| Third stage - Grand Central or ABL | |
| Engines | 1 Solid |
| Thrust | 2,599 lbf (11.56 kN) |
| Specific impulse | 230 seconds |
| Burn time | 31 s |
| Fuel | Solid |
The Vanguard rocket was intended to be the first launch vehicle the United States would use to place a satellite into orbit. Instead, the Sputnik crisis caused by the surprise launch of Sputnik 1 led the U.S., after the failure of Vanguard TV3, to quickly orbit the Explorer 1 satellite using a Juno I rocket, making Vanguard I the second successful U.S. orbital launch.
Vanguard rockets were used by Project Vanguard from 1957 to 1959. Of the eleven Vanguard rockets which the project attempted to launch, three successfully placed satellites into orbit. Vanguard rockets were an important part of the space race between the United States and the Soviet Union.
In 1955, the United States announced plans to put a scientific satellite in orbit for the International Geophysical Year (IGY) in 1957–1958. The goal was to track the satellite as it performed experiments. At that time there were three candidates for the launch vehicle: The Air Force's SM-65 Atlas, a derivative of the Army Ballistic Missile Agency's SSM-A-14 Redstone, and a Navy proposal for a three-stage rocket based on the RTV-N-12a Viking sounding rocket.
The Rand Corporation, Air Force and CIA had long pursued the idea of a Reconnaissance Satellite. Such a program was under way, Weapon System 117L, which was top secret compartmented. One problem with a reconnaissance was a matter of legality, was there "freedom of space" or did a nation's airspace end when space is entered? The National Security Council backed the IGY satellite as it would make good cover for WS117L and set a precedent of freedom of space peaceful civilian satellite. At the same time the NSC stressed that the IGY satellite must not interfere with military programs. " The Army's Redstone-based proposal would likely be first ready for a first satellite launch. Its connection with German-born scientist Wernher von Braun, however, was a public-relations risk. In any case, the Atlas and Redstone ballistic missiles were top-priority military projects, which were not to be slowed by pursuing a secondary space launch mission.Milton Rosen's Vanguard was a project at the Naval Research Laboratory (NRL), which was regarded more as a scientific than a military organization. Rosen and Richard Porter (IGY satellite chief and head of the American Rocket Society) both lobbied for the Vanguard and against using the Atlas or von Braun's rockets. They emphasized the non-military goals of the satellite program. Besides the public-relations aspect, a non-military satellite was considered important, because a discussion of whether overflights of foreign countries by satellites were legal or illegal was to be avoided.
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Wikipedia