Saturday, May 6, 1989
Friday, May 5, 1989
Thursday, May 4, 1989
Explorer 15
1962-059A
The EPE-C (Energetic Particles Explorer C, S-003B) payload was modified for the SERBD (Study of Enhanced Radiation Belt Dynamics) mission, to analyse the new population of trapped particles around the Earth created by the US STARFISH nuclear explosion; it also detected particle injections by USSR high altitude nuclear tests. It was launched on 1962 Oct 27 at 2315:01 by Delta A from Canaveral into a 313 x 17640 km x 18.0 deg orbit. Explorer XV transmitted until 1963 Feb 9. In the 1980s Space Command recorded a decay date of 1983 Dec 19, but in 2000 this was amended to 1978 Jan 15, presumably following review of archival data. Satellite number 5992 is probably a rediscovery of Explorer 15.
This was the first launch from the Cape to a low inclination, involving a dogleg burn either in the Delta or the Altair phases. The Altair would have provided a total delta-V of around 3.5km/s. As a possible reconstruction, we can find a Delta trajectory of -1980 x 307 x 30.3 deg and a 30 degree yaw on the Altair apogee burn, which is a plausible solution. Alternatively, a -2380 x 306 x 28.6 deg Delta trajectory with a 25 degree Altair yaw gives the same final orbit. This is the minimum likely Delta inclination, so I adopt it as my reference solution.
| Explorer 15 | |||
| Date | Time | Event | Orbit |
|---|---|---|---|
| 1962 Oct 27 | 2315:01 | Launch by Delta | CC LC17B |
| 2317:22 | T+2:21 MECO 82.6 km 4.918 km/s | -5030 x 300 ? | |
| Thor sep | |||
| 2317 | Delta S/N 2022 burn, 1:47 | ||
| 2319 | Delta SECO | -2380? x 306 x 28.6 | |
| 2328? | Altair burn, with yaw | ||
| 2330 | Altair sep | 313 x 17640 x 18.0 | |
| 1963 Feb 9 | End of ops | ||
| 1963 May 19 | End of tx | ||
| 1978 Jan 15 | Reentered | ||