FR-1 (satellite)
Cutaway replica of FR-1 at the Musée de l'air et de l'espace | |
| Names | FR-1 FR1 FR 1: 27 FR.1: 26–27 FR-1A FRANCE FRANCE 1: 27 France 1 French 1 |
|---|---|
| Mission type | Scientific |
| Operator | CNES, CNET, NASA |
| Harvard designation | 1965-101A |
| COSPAR ID | 1965-101A |
| SATCAT no. | 1814 |
| Mission duration | 1,180 days |
| Spacecraft properties | |
| Manufacturer | CNES, CNET, Nord Aviation |
| Launch mass | 60 kg (130 lb), 71.7 kg (158 lb), or 135 lb (61 kg) |
| Start of mission | |
| Launch date | 6 December 1965, 21:05:47 UTC |
| Rocket | Scout X-4 |
| Launch site | Vandenberg Air Force Base Western Range |
| End of mission | |
| Last contact | 28 February 1969 |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Low Earth |
| Semi-major axis | 7,049 kilometres (4,380 mi) |
| Perigee altitude | 696 kilometres (432 mi) |
| Apogee altitude | 707 kilometres (439 mi) |
| Inclination | 75.9 degrees |
| Period | 98.2 minutes |
| Epoch | 6 December 1965 |
FR-1 was the second French satellite. Planned as the first French satellite, it was launched on 6 December 1965—ten days after the actual first French satellite, Astérix—by an American Scout X-4 rocket from the Western Range at Vandenberg Air Force Base. The scientific satellite studied the composition and structure of the ionosphere, plasmasphere, and magnetosphere by measuring the propagation of very low frequency (VLF) waves and the electron density of plasma in those portions of the Earth's atmosphere. FR-1's VLF receiver operated until 26 August 1968. FR-1 remains in orbit as of 2023.