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Vanguard TV3



Vanguard Test Vehicle 3 (TV3) was the first U.S. attempt to launch a satellite into orbit around the Earth. It was a small satellite designed to test the launch capabilities of a three-stage launch vehicle and study the effects of the environment on a satellite and its systems in Earth orbit. It also was to be used to study micrometeor impacts and to obtain geodetic measurements through orbit analysis. The IGY Vanguard satellite program was designed with the purpose of launching one or more Earth orbiting satellites during the International Geophysical Year (IGY).

At launch on 6 December 1957 at 16:44:34 UT at the Atlantic Missile Range in Cape Canaveral, Florida, the booster ignited and began to rise but about 2 seconds after liftoff, after rising about a meter, the rocket lost thrust and began to settle back down to the launch pad. As it settled against the launch pad the fuel tanks ruptured and exploded, destroying the rocket and severely damaging the launch pad. The Vanguard satellite was thrown clear and landed on the ground a short distance away with its transmitters still sending out a beacon signal. The satellite was damaged, however, and could not be reused. It is now on display at the Smithsonian Air and Space Museum.

The exact cause of the accident was never determined, presumably it was due to a fuel leak between the fuel tank and the rocket engine, possibly due to a loose connection in a fuel line or low fuel pump inlet pressure allowing some of the burning fuel in the thrust chamber to leak back into the fuel tank.

Spacecraft and Subsystems

The spacecraft was an approximately 1.5-kg aluminum sphere 16.3 cm in diameter, nearly identical to the later Vanguard 1. A cylinder lined with heat shields mounted inside the sphere held the instrument payload. It contained a set of mercury-batteries, a 10-mW, 108-MHz telemetry transmitter powered by the batteries, and a 5-mW, 108.03-MHz Minitrack beacon transmitter, which was powered by six square (roughly 5 cm on a side) solar cells mounted on the body of the satellite. Six 30-cm long, 0.8-cm diameter spring-actuated aluminum alloy aerials protruded from the sphere. On actuation, the aerial axes were mutually perpendicular in lines that passed through the center of the sphere. The transmitters were primarily for engineering and tracking data, but were also to determine the total electron content between the satellite and ground stations. Vanguard also carried two thermistors which could measur the interior temperature in order to track the effectiveness of the thermal protection.

A cylindrical separation device was designd to keep the sphere attached to the third stage prior to deployment. At deployment a strap holding the satellite in place would be released and three leaf springs would separate the satellite from the cylinder and third stage at a relative velocity of about 0.3 m/s.

Launch Vehicle

Vanguard was the designation used for both the launch vehicle and the satellite. The first stage of the three-stage Vanguard Test vehicle was powered by a GE X-405 28,000 pound (~125,000 N) thrust liquid rocket engine, propelled by 7200 kg of kerosene (RP-1) and liquid oxygen, with helium pressurant. It also held 152 kg of hydrogen peroxide. It was finless, 13.4 m (44 ft.) tall, 1.14 m (45 in.) in diameter, and had a launch mass of approximately 8090 kg (17,800 lbs. wt.).

The second stage was a 5.8 m (19 ft.) high, 0.8 m (31.5 in.) diameter Aerojet-General AJ-10 liquid engine burning 1520 kg (3350 lbs) Unsymmetrical Dimethylhydrazine (UDMH) and White Inhibited Fuming Nitric Acid (WIFNA) with a helium pressurant tank. It produced a thrust of 7340 pounds (~32,600 N) and had a launch mass of approximately 1990 kg (4390 lbs. wt.). This stage contained the complete guidance and control system.

A solid-propellant rocket with 2350 pounds (~ 10,400 N) of thrust (for 30 seconds burn time) was developed by the Grand Central Rocket Co. to satisfy third-stage requirements. The stage was 1.5 m (60 in.) high, 0.8 m (31.5 in.) in diameter, and had a launch mass of 194 kg (428 lbs.). The thin (0.076 cm, 0.03 in.) steel casing for the third stage had a hemispherical forward dome with a shaft at the center to support the satellite and an aft dome fairing into a steel exit nozzle.

The total height of the vehicle with the satellite fairing was about 21.9 meters (72 feet). The payload capacity was 11.3 kg (25 lbs.) to a 555 km (345 mi.) Earth orbit. A nominal launch would have the first stage firing for 144 seconds, bringing the rocket to an altitude of 58 km (36 mi), followed by the second stage burn of 120 seconds to 480 km (300 mi), whereupon the third stage would bring the satellite to orbit. This was the same launch vehicle configuration, with minor modifications, as used all succeeding Vanguard flights up to and including Vanguard SLV-6.

Alternate Names

  • VanguardTV3

Facts in Brief

Launch Date: 1957-12-06
Launch Vehicle: Vanguard
Launch Site: Cape Canaveral, United States
Mass: 1.5 kg

Funding Agency

  • Department of Defense-Department of the Navy (United States)


  • Communications

Additional Information

Questions and comments about this spacecraft can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail

Related Information/Data at NSSDCA

Vanguard 1

Other Sources of Vanguard Information

Vanguard, a History - NASA document SP-4202 online

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