1993-039A
Owned by Hughes Communications Inc., Galaxy 4H was a hybrid satellite, carrying both C and Ku band transponders. It was a three-axis stabilized HS-601 unlike the earlier Galaxy craft, and had a mass of 2700 kg. Galaxy 4H was intended for television distribution and private communications networks.
The satellite had a solar array span of 26.5m. Mass was 2988 kg at orbital injection, 1692 kg on station, and 1323 kg empty. The Ariane stage was not tracked and probably reentred on first orbit.
In May 1998 a chip in the on board control processor failed, sending the spacecraft spinning and putting 90 percent of the pagers in the USA out of action. PanAmSat deactivated the communications payload and put the satellite in safemode. The Ku-band customers were transferred to Galaxy III-R, while Galaxy VI was moved from 74W to 99W to backup the C-band capacity. An investigation suggested an electrical short in a tin-plated relay in the processor was responsible.
| Galaxy IVH | |||
| Date | Time | Event | Orbit |
|---|---|---|---|
| 1993 Jun 25 | 0018:00 | Launch by Ariane 42P | |
| 0021 | L-33 Stage 2 TIG (T+3:30) | ||
| 0022 | Type 01 Fairing sep (T+4:35) | ||
| 0023 | L-33 Stage 2 sep (T+5:30) | ||
| 0023 | H-10+ TIG (T+5:43) | ||
| 0036 | H-10+ MECO (T+18:11) | ||
| 0038 | H10+ stage sep | ||
| Orbit insertion | 200 x 27668 x 7.0 | ||
| 0040 | H10+ sep burn, end of mission | ||
| 486.84 293 x 27949 x 7.1 | |||
| 1993 Jun 26 | 0000? | PVA burn 1 | 548.33 232 x 31394 x 7.5 |
| 1993 Jun 27 | 1200? | PVA burn 2 | 633.46 218 x 35890 x 7.0 |
| 1993 Jun 30 | 0030? | AKM-1 burn at 12th apogee | 1069.56 20627 x 35905 x 1.1 |
| 1993 Jun 30 | 1073.95 20860 x 35861 x 1.1 | ||
| 1993 Jul 2? | AKM-2 burn | ||
| 1993 Jul 3? | AKM-3 burn | 1437.13 35689 x 35924 x 0.1 GEO 88.8W+0.3W | |
| 1993 Jul 5? | Solar panels deploy | ||
| 1993 Jul | (s) | GEO 99W? | |
| 1993 Oct 21 | 1429.52 35531 x 35784 x 0.3 GEO 99.0W+1.6E | ||
| 1993 Nov 29 | 1436.08 35774 x 35798 x 0.0 GEO 99.0W | ||
| 1994 Aug 28 | 1436.11 35776 x 35797 x 0.0 GEO 99.0W | ||
| 1997 Mar 19 | 1436.12 35776 x 35797 x 0.0 GEO 99.0W | ||
| 1997 May 16 | To Panamsat | GEO 99W | |
| 1998 May 19 | 2230 | Attitude control failed | |
| 1998 May 27 | 1436.11 35777 x 35795 x 0.1 GEO 99.0W | ||
| 1998 May 27 | Orbit raised | 1446.53 35885 x 36096 x 0.1 | |
| 1999 Jun? | To Hughes Comms Galaxy as HGS-4 | ||
| 1999 Aug | Reverse drift to stop at 147W | ||
| 1999 Aug 17 | 1444.64 35893 x 36013 x 0.9 | ||
| 1999 Aug 21 | 1432.77 35548 x 35894 x 0.9 GEO 163.7W | ||
| 1999 Oct 16 | 1436.06 35654 x 35917 x 1.1 GEO 148.0W | ||
| 2000 Feb 22 | 1436.14 35611 x 35963 x 1.4 GEO 148.9W | ||
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