1978-012A
The International Ultraviolet Explorer was designed for a six month mission but was still operating 16 years later. IUE took ultraviolet spectra of astronomical objects - tens of thousands of them. It was the first astronomy satellite to be operated as an observatory, available for use by the whole astronomical community. Uniquely, it was in geosynchronous orbit, so that astronomers at the NASA-Goddard or ESA-Villafranca control centers could control the spectrographs in real time. IUE was jointly funded by NASA, ESA, and the UK Science Research Council; the orbit drifted back and forward across the Atlantic and observing was handled from the ESA ground station for 8 hours a day and from Goddard for 16 hours a day.
IUE was launched on 1978 Jan 26 at 1736 by a Delta 2914 from Cape Canaveral's Launch Complex 17A. The Delta stage entered a 96.6 min, 164 x 1024 km x 28.7 deg and separated from the third stage. The Star 37E third stage fired and placed IUE in a 846.7 min, 177 x 46367 km x 28.7 deg orbit. The Star 24 apogee motor fired to put the satellite in a final orbit of 1435.7 min, 25669 x 45888 km x 28.6 deg. Observations began a few days later. The internal propulsion system was used occasionally to maintain the satellite at the correct longitude.
On 1995 Oct 1 operational control of IUE was transferred completely to ESA-Villafranca. ESA and PPARC (the successor to SERC) would operate the spacecraft. IUE was shut down at 1842 UT on 1996 Sep 30.
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| IUE |
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| Date | Time | Event | Orbit |
|---|
|
| 1978 Jan 26 | 1736:00 | Launch by Delta 2914 | CC LC17A |
| | 0135:38 | SRM 1-6 cutoff |
| | 0135:39 | SRM7-9 burn |
| | 0136:17 | SRM7-9 cutoff |
| | 0136:27 | SRM 1-9 sep |
| | | T+3:42 MECO |
| | | T+3:49 Stage 1 sep |
| | | T+3:55 Stage 2 burn |
| | 1740 | T+4:33 Fairing sep |
| | 1745 | T+8:47 SECO-1 164 km vrel 7.807 | 167 x 167? x 28.7 |
| | 1816 | T+40:12 SES-2 172 km vrel 7.797 |
| | 1816 | T+40:30 SECO-2 172 km 8.024 | 96.6 164 x 1024 x 28.7 |
| | 1817 | T+41:22 Stage 2 sep 170 km 8.026 |
| | 1818 | T+42:03 TES 172 km 8.025 |
| | 1818 | T+42:47 TECO 176 km | 846.7 177 x 46367 x 28.7 |
| | 1819 | T+43:50 S/C sep 204 km |
| 1978 Jan 27 | 0300? | Apo 1 |
| 1978 Jan 27 | 1454 | Star 24 burn, apo 2 | 1435.7 25669 x 45888 x 28.6 |
| 1978 Jan 28 | | Despin using HAPS |
| 1978 Jan 28 | 0602 | | 1435.64 25668 x 45886 x 28.6 55.2W |
| 1978 Jan 30 | 1630 | Dust cover ejected |
| 1978 Feb 1 | | First images from FES |
| 1978 Feb 9 | | First data currently in archive |
| 1978 Feb 13 | | Orbit correction |
| 1978 Mar 30 | | | 1436.38 25711 x 45872 x 28.6 51.8W |
| 1978 Jul 24 | | Orbit correction |
| 1979 Jun 20 | | Orbit correction |
| 1980 Feb 13 | | Orbit correction |
| 1980 Apr 18 | | | 1435.66 25888 x 45667 x 28.2 |
| 1980 Jun 24 | | Orbit correction |
| 1980 Dec 16 | | Orbit correction |
| 1981 May 8 | | Orbit correction | 1436.07 26080 x 45491 x 28.3 |
| 1981 Oct 29 | | Orbit correction |
| 1982 Aug 17 | | Orbit correction | 1435.54 26426 x 45125 x 28.6 |
| 1983 May 27 | | Orbit correction |
| 1984 Jan 12 | | Orbit correction |
| 1984 Feb 14 | | Orbit correction |
| 1984 Nov 16 | | Orbit correction |
| 1985 Jul 16 | | | 1436.63 27451 x 44142 x 29.7 |
| 1985 Aug 9 | | Orbit correction |
| 1985 Sep 6 | | | 1435.59 27533 x 44020 x 29.8 |
| 1986 Mar 19 | | Orbit correction |
| 1986 Jul 29 | | Orbit correction | 1435.81 27952 x 43609 x 30.2 |
| 1986 Dec 18 | | Orbit correction |
| 1987 Sep 9 | | Orbit correction |
| 1988 Mar 18 | | Orbit correction |
| 1988 Sep 8 | | Orbit correction |
| 1989 Mar 13 | | Orbit correction |
| 1989 Sep 8 | | Orbit correction |
| 1990 Jun 6 | | Orbit correction |
| 1990 Dec 3 | | | 1436.35 29787 x 41795 x 32.6 53.5W |
| 1991 Jan 14 | | | 1436.46 29799 x 41787 x 32.3 56.9W |
| 1991 Jan 12 | | Orbit correction |
| 1991 Feb 6 | | | 1435.64 29811 x 41743 x 32.7 |
| 1991 Nov 5 | | | 1436.74 29881 x 41716 x 33.0 57.4W |
| 1991 Oct 18 | | Orbit correction | 1435.91 30045 x 41520 x 33.3 51.7W |
| 1992 Aug 18 | | | 1436.86 30160 x 41443 x 33.5 68.6W |
| 1992 Aug 19 | | Orbit correction | 1435.72 30162 x 41395 x 33.5 68.0W |
| 1992 Nov 19 | | | 1436.07 30208 x 41363 x 33.7 64.3W |
| 1992 Nov 20 | | Orbit correction | 1435.41 30213 x 41333 x 33.7 64.1W |
| 1993 Aug 17 | | | 1436.53 30264 x 41325 x 34.1 45.2W |
| 1993 Aug 19 | | Orbit correction | 1435.77 30256 x 41304 x 34.1 46.1W |
| 1993 Sep 20 | | | 1435.84 30264 x 41299 x 34.2 51.1W |
| 1994 Feb 14 | | | 1436.49 30242 x 41346 x 34.5 57.4W |
| 1994 Feb 15 | | Orbit correction | 1435.67 30243 x 41312 x 34.5 57.4W |
| 1994 Sep 20 | | | 1436.60 30235 x 41357 x 34.8 55.4W |
| 1994 Sep 20 | | Orbit correction | 1435.55 30243 x 41308 x 34.8 52.9W |
| 1995 Apr 30 | | | 1436.58 30207 x 41384 x 35.1 48.4W |
| 1995 May 3 | | Orbit correction | 1435.85 30183 x 41380 x 35.1 48.1W |
| 1995 Jun 5 | | | 1435.98 30178 x 41389 x 35.2 |
| 1995 Jun 6 | | Orbit correction | 1435.19 30162 x 41374 x 35.2 |
| 1996 Mar 5 | | | 1436.21 30095 x 41482 x 35.6 35.8W |
| 1996 Mar 6 | | Command error, control lost |
| 1996 Mar 11 | | One-gyro control enabled |
| 1996 Sep 29 | | | 1437.04 29992 x 41617 x 35.9 65.5W |
| 1996 Sep 30 | 1357 | Science cameras off |
| | 1730 | Propellant drained (18 kg) |
| | 1842 | Spacecraft deactivated |
| 1996 Oct 10 | | | 1439.04 30216 x 41472 x 35.6 |
| 1999 Apr 27 | | | 1438.85 29739 x 41941 x 37.2 |
Payload:
- Telescope 45 cm Ritchey-Chretien telescope