| Launch date | 07:15:41 am EST 17 March 1958 |
| Mission | Prim:test-- SEC:High atmosphere study |
| Perigee/Apogee | Click here |
| Inclination | Click here |
| Period | Click here |
| Launch vehicle | Test Vehicle 4 |
| Launch site | Cape Canaveral |
| Diameter | 6.4 inch |
| Mass at launch | 1.47 kilogram (3.25 pound) |
| Visibility | 12 - 15.th mag. |
| Time in orbit | 250 - 600 years The lifetime of a satellite is highly dependent on the future solar activity
which effects the atmospheric drag a satellite experiences. |
| Instruments | Temperature sounder |
| Radio | Two transmitters 100 and 50 mW |
| Source of energy | Mercury battery and 6 solar panels |
| Transmitting freq. | 108.00 and 108.03 MHZ |
| Transmitter lifetime | 6 years 3 month |