1991-062A
The Solar-A satellite was launched in Aug 1991. It was renamed Yohkoh (`Sunlight'). Yohkoh returned daily X-ray images of the Sun with the NASA soft X-ray telescope.
After 10 years in space, Yohkoh lost attitude control during a solar eclipse which happened at a time of poor ground communications; the batteries drained to a low state and the spacecraft is oriented in a way that keeps them cold. Yohkoh was decommissioned the following year.
| Yohkoh | |||
| Date | Time | Event | Orbit |
|---|---|---|---|
| 1991 Aug 30 | 0230 | Launch by Mu 3S2 | KASC |
| T+0:40 SOB sep | |||
| T+1:24 Stage 1 cutoff, sep | |||
| T+1:26 Stage 2 start | |||
| T+2:36 Stage 2 cutoff, coast | |||
| T+2:35 Fairing | |||
| 0233 | T+3:15 Stage 3 spinup | ||
| 0234 | T+4:00 Stage 2 sep | ||
| 0237 | T+7:13 Stage 3 burn 87s? at 570 km | ||
| 0238 | T+8:40? M3B rocket cutoff | ||
| 0239 | T+9:30 M3B sep | ||
| 0239 | T+9:40 Yo-yo despin | ||
| 520 x 770 x 31.3 | |||
| 1991 Nov 20 | 97.87 522 x 791 x 31.3 | ||
| 2001 Dec 14 | Discharged batteries during eclipse | ||
| 2002 Jun | end of ops | ||
Payload:
- HXT Hard imaging XR telescope ISAS 10-100 keV, 8" res. (Fourier synthesis telescope; 64 PMT array )
- SXT Soft imaging XR telescope NASA-MSFC/LPARL 2" resolution 0.25 - 4 keV, 4-50A, 1.6m focal length Nariai-Werner, with CCD. Aperture 1 cm?
- BCS Bragg crystal spectrometer ISAS/UK; 1.8-5A
- WBXS Wide band soft X spectrometer ISAS 2 keV - 100 MeV.
