NSSDC ID: 1958-002B
Vanguard 1 was a small earth-orbiting satellite designed to test the launch capabilities of a three-stage launch vehicle and the effects of the environment on a satellite and its systems in Earth orbit. It also was used to obtain geodetic measurements through orbit analysis.
The spacecraft was a 1.47-kg aluminum sphere 16.5 cm in diameter. It contained a 10-mW, 108-MHz mercury-battery powered transmitter and a 5-mW, 108.03-MHz transmitter powered by six square (roughly 5 cm on a side) solar cells mounted on the body of the satellite. Six 30 cm aerials protruded from the sphere. The transmitters were used primarily for engineering and tracking data, but were also used to determine the total electron content between the satellite and ground stations. Vanguard also carried two thermistors which measured the interior temperature over 16 days in order to track the effectiveness of the thermal protection.
The three stage launch vehicle placed Vanguard into a 654 x 3969 km 134.2 minute orbit inclined at 34.25 degrees. Original estimates had the orbit lasting for 2000 years, but it was discovered that solar radiation pressure and atmospheric drag during high levels of solar activity produced significant perturbations in the perigee height of the satellite, which caused a significant decrease in its expected lifetime to only about 240 years. The battery powered transmitter stopped operating in June 1958 when the batteries ran down. The solar powered transmitter operated until May 1964 (when the last signals were received in Quito, Ecuador) after which the spacecraft was optically tracked from Earth.
Launch Date: 1958-03-17
Launch Vehicle: Vanguard
Launch Site: Cape Canaveral, United States
Mass: 1.47 kg
Data collections from Vanguard 1
Questions or comments about this spacecraft can be directed to: Dr. David R. Williams.
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. J. P. Hagen | Project Scientist | US Naval Research Laboratory |
Easton, R. L., and M. J. Votaw, Vanguard I IGY satellite (1958 Beta), Rev. Sci. Instrum., 30, 70-75, Feb. 1959.
Siry, J. W., Vanguard IGY earth satellite program, Ann. Intern. Geophys. Year, 12, Part 1, 64-75, 1960.
Green, C. M., Vanguard - a history, NASA, SP-4202, Wash., DC, 1970.
This image shows the Vanguard TV-3 satellite, displayed at the Smithsonian Air and Space Museum. The TV-3 launch, on 06 December 1957, failed and the Vanguard satellite was thrown clear. The aerials were bent and other damage occurred when it hit the ground, so it could not be re-flown, but the satellite was identical to the Vanguard 1.
Vanguard, a History - NASA document SP-4202 online