 Explorer 20 satellite | |
| Names | IE-A Ionospheric Explorer-A NASA S-48 TOPSI Topside Explorer |
|---|---|
| Mission type | Ionospheric research |
| Operator | NASA |
| COSPAR ID | 1964-051A |
| SATCAT no. | 00870 |
| Mission duration | 12 months (planned) 16 months (achieved) |
| Spacecraft properties | |
| Spacecraft | Explorer XX |
| Spacecraft type | Ionospheric Explorer |
| Bus | IE |
| Manufacturer | Cutler-Hammer |
| Launch mass | 44.5 kg (98 lb) |
| Power | Solar cells and batteries |
| Start of mission | |
| Launch date | 25 August 1964, 13:43 GMT |
| Rocket | Scout X-4 (S-134R) |
| Launch site | Vandenberg, SLC-5[1][2] |
| Contractor | Vought |
| Entered service | 25 August 1964 |
| End of mission | |
| Last contact | 20 December 1965 |
| Orbital parameters | |
| Reference system | Geocentric orbit |
| Regime | Low Earth orbit |
| Perigee altitude | 864 km (537 mi) |
| Apogee altitude | 1,025 km (637 mi) |
| Inclination | 79.90° |
| Period | 104.00 minutes |
| Instruments | |
| Cosmic Noise Fixed-Frequency Ionosonde Spherical Ion-Mass Spectrometer | |
Explorer program | |
Explorer 20, also known Ionosphere Explorer-A, IE-A, S-48, TOPSI and Topside Explorer, was a NASA satellite launched as part of Explorer program. Its purpose was two-fold: long-term investigation of the ionosphere from above, and in situ investigation of ion concentrations and temperatures.
- ^ "IE". Encyclopedia Astronautica. Mark Wade. Archived from the original on 21 June 2002. Retrieved 9 June 2018.
- ^ "Letter dated 12 October 1964 from the Permanent Representative of the United States of America addressed to the Secretary-General" (PDF). COMMITTEE ON THE PEACEFUL USES OF OUTER SPACE. Retrieved 5 December 2022.