 The launch of Vanguard SLV-1, which failed at second-stage burnout. | |
| Names | Vanguard Space Launch Vehicle-1 |
|---|---|
| Mission type | International Geophysical Year |
| Operator | Naval Research Laboratory |
| Mission duration | Failed to orbit |
| Spacecraft properties | |
| Spacecraft | Vanguard 2B |
| Spacecraft type | Vanguard |
| Manufacturer | Naval Research Laboratory |
| Launch mass | 9.75 kg (21.5 lb) |
| Dimensions | 50.8 cm (20.0 in) of diameter |
| Start of mission | |
| Launch date | 28 May 1958, 03:46:20 GMT |
| Rocket | Vanguard SLV-1 |
| Launch site | Cape Canaveral, LC-18A |
| Contractor | Glenn L. Martin Company |
| End of mission | |
| Decay date | Failed to orbit |
| Orbital parameters | |
| Reference system | Geocentric orbit (planned) |
| Regime | Medium Earth orbit |
| Perigee altitude | 655 km |
| Apogee altitude | 3970 km |
| Inclination | 34.20° |
| Period | 134.0 minutes |
Vanguard SLV-1, also called Vanguard Satellite Launch Vehicle-1 was hoped to be the second successful flight of the American Vanguard rocket following the successful launch of the Vanguard 1 satellite on rocket Vanguard TV-4 in March 1958.