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Calsphere 1, 2, 3, 4
Calsphere [NRL]
The Calsphere (Calibration Sphere) satellites were passive spherical surveillance calibration target built by the Naval Research Laboratory (NRL).
These satellites were launched on three cluster launches of multiple small satellites:
- Calsphere 1 was launched on a Thor-DM21 Agena-D in December 1962 with a pair of Poppy 3 SIGINT satellites and some small payloads, but entered an elliptical orbit due to a launch vehicle error.
- Calsphere 2 was successfully launched in 1965 on a Thor-DSV2A Able-Star sharing the flight with the Transit-O 5 navigational satellite and some small payloads.
- Calsphere 3 and 4 were launched together on a Thor-DM21 Agena-D mission, sharing the launch with four Poppy 7 SIGINT satellites and a number of small satellites.
| Nation: | USA |
|---|---|
| Type / Application: | Radar calibration |
| Operator: | Naval Research Laboratory (NRL) |
| Contractors: | Naval Research Laboratory (NRL) |
| Equipment: | None |
| Configuration: | Sphere |
| Propulsion: | None |
| Power: | None |
| Lifetime: | Passive |
| Mass: | 1.4 kg (#1); 4 kg (#2); 4.5 kg (#3); 5 kg (#4) |
| Orbit: | 231 km × 2748 km, 70.34° (#1); 1083 km × 1194 km, 90.04° (#2); 913 km × 936 km, 69.97° (#3); 914 km × 925 km, 69.98° (#4) |
| Satellite | COSPAR | Date | LS | Launch Vehicle | Remarks | |
|---|---|---|---|---|---|---|
| Calsphere 1 | 1962 βτ 5 | 13.12.1962 | Va 75-1-1 | P | Thor-DM21 Agena-D | with Poppy 3A, Poppy 3B, Injun 3, Surcal 2, Wild Bill 2 |
| Calsphere 2 (NRL-PL 158 ?) | 1965-065H | 13.08.1965 | Va 75-1-1 | Thor-DSV2A Able-Star | with Transit-O 5, Long Rod, Tempsat 1, Dodecapole 2, Surcal 5 | |
| Calsphere 3 (NRL-PL 160) | 1967-053A | 31.05.1967 | Va SLC-2W | Thor-DM21 Agena-D | with Poppy 7A, Poppy 7B (GGSE 4), Poppy 7C, Poppy 7D (GGSE 5), Timation 1, Calsphere 4, NRL-PL 150B, OPS 5712 | |
| Calsphere 4 (NRL-PL 159) | 1967-053F | 31.05.1967 | Va SLC-2W | Thor-DM21 Agena-D | with Poppy 7A, Poppy 7B (GGSE 4), Poppy 7C, Poppy 7D (GGSE 5), Timation 1, Calsphere 3, NRL-PL 150B, OPS 5712 |
References:
- Jonathan McDowell: Naval Research Laboratory Satellites 1960-1989, 1995
Further NRL calibration missions:
