Vanguard 1
Vanguard 1 (Harvard designation: 1958-Beta 2, COSPAR ID: 1958-002B) is an American satellite that was the fourth artificial Earth-orbiting satellite to be successfully launched, following Sputnik 1, Sputnik 2, and Explorer 1. It was launched 17 March 1958. Vanguard 1 was the first satellite to have solar electric power. Although communications with the satellite were lost in 1964, it remains the oldest human-made object still in orbit, together with the upper stage of its launch vehicle.
A model of Vanguard 1 | |
| Names | Vanguard TV-4 Vanguard Test Vehicle-Four |
|---|---|
| Mission type | Earth science |
| Operator | Naval Research Laboratory |
| Harvard designation | 1958-Beta 2 |
| COSPAR ID | 1958-002B |
| SATCAT no. | 00005 |
| Mission duration | Planned: 90 days In Orbit: 65 years, 10 months and 30 days |
| Spacecraft properties | |
| Spacecraft | Vanguard 1 |
| Spacecraft type | Vanguard |
| Manufacturer | Naval Research Laboratory |
| Launch mass | 1.46 kg (3.2 lb) |
| Dimensions | 152 mm (6.0 in) diameter, 3.0 ft (0.91 m) antenna span |
| Start of mission | |
| Launch date | 17 March 1958, 12:15:41 GMT |
| Rocket | Vanguard TV-4 |
| Launch site | Cape Canaveral, LC-18A |
| Contractor | Glenn L. Martin Company |
| End of mission | |
| Last contact | May 1964 |
| Decay date | 2198 (estimated) ~ 240 years orbital lifetime |
| Orbital parameters | |
| Reference system | Geocentric orbit |
| Regime | Medium Earth orbit |
| Perigee altitude | 654 km (406 mi) |
| Apogee altitude | 3,969 km (2,466 mi) |
| Inclination | 34.25° |
| Period | 134.27 minutes |
Vanguard 1 was designed to test the launch capabilities of a three-stage launch vehicle as a part of Project Vanguard, and the effects of the space environment on a satellite and its systems in Earth orbit. It also was used to obtain geodetic measurements through orbit analysis. Vanguard 1, being small and light enough to carry with one hand, was described by the Soviet Premier, Nikita Khrushchev, as "the grapefruit satellite".