1984-015A
The EXOS-C satellite was dedicated to studies of the straosphere and mesosphere. It was named Ohzora (`Sky') once reaching orbit. Mass of EXOS C was 207 kg. Size is 0.88m high 0.94m dia octagon with 4 panels span 2.8m.
The launch took off towards a 58 degree inclination but then made dog-legs to the south to increase the inclination to a final 71.4 deg.
The M-3S-4 third stage had an improved M-3A4 motor with a new propellant mix. It burned for an unexpectedly long time and with lower performance than planned, and had residual thrust that could have caused a collision after payload separation. The separation sequence of later launches was modified to use a 2m/s separation velocity, twice the previous.
Stage 3 1313f 150 em Isp was now 289s, thrust 63.3 kN, burn time 52s (or 60s?) dv = 2834 ln 1520.4/357.4 = 4103m/s
|
| Ohzora |
| |
|
| Date | Time | Event | Orbit |
|---|
|
| 1984 Feb 14 | 0800 | Launch by Mu 3S M-3S-4 | KASC |
| | | T+0:09 SB sep |
| | | T+1:24 B1 sep | -6235 x 98 x 58.60 |
| | | T+1:26 B2 burn |
| | | T+3:11? B2 burnout | -5441 x 361 x 71.41 |
| | | T+3:11 B2 orbit epoch |
| | | T+4:01 Spinup |
| | | T+6:16 Stage 2 sep |
| | | T+6:20 M3A4 burn |
| | 0807 | T+7:20 M3A4 burnout |
| | 0808 | T+8:10 Stage 3 sep | 96.9 354 x 865 x 74.6 |
| | 0808 | T+8:15 Stage 3 collides with payload? |
| 1986 Nov | | Cataloged 15D,E | (328 x 597 x 74.6) |
| 1987 Sep | | End of ops with BUV |
| 1989 Jul 19 | | Reentered | 154 x 172 x 74.6 |
Payload:
- BUV backscatter UV spectrometer and 4100A albedo radiometer
- Electron,proton,alpha monitor
- Limb scanning IR radiometer
- Precipitating particle energies
- IR solar spectrometer
- Topside plasma sounder
- Solar horizon image radiometer
