1975-083A
The Viking A spacecraft was launched on 1975 Sep 9 at 1839 by Titan IIIE Centaur from Cape Canaveral and became Viking 2.
The initial injection had a closest approach at 1976 Aug 9 0919 UTC with a miss distance of 655575 km (BT,BR= 581970, -301786).
Once in solar orbit, the MC1 burn was made on Sep 19 to correct the trajectory. An approach burn was made on 1976 Jul 27.
Mars Orbit Insertion was on 1976 Aug 7. A series of orbit trim burns were made to synchronize the orbit, ending with MOT4 on Aug 27. The Lander was separated on Sep 3. In this case, the bioshield base remained attached to the Orbiter, VO-2.
After a propulsion test on Sep 29, a major orbit change was made on Sep 30, with the inclination increased to 75 deg. The Viking Extended Mission began on 1976 Dec 14. On 1977 Mar 2, VO-2 had re-synchronized its orbit over the VL-2 landing site. On 1977 Apr 18, the Survival Automatic Mission was begun while Mars approached perihelion (Apr 30).
On 1977 Sep 26, VO-2 trimmed its orbit to approach Deimos. Another burn on Oct 9 synchronized the orbit with that of Deimos. Deimos encounters followed on Oct 10, Oct 12, Oct 15, and twice more in the Oct 16-22 period. The Oct 15 encounter was only 33km from the center of Deimos. A burn on Oct 23 ended the Deimos encounter period.
The Bioshield base was finally jettisoned on 1978 Mar 3. After Mars aphelion on Apr 9, the Viking Contination Mission began on May 31. However, VO-2's attitude gas was exhausted at 0601 on 1978 Jul 24 and the mission came to a close.
| VO2 | |||
| Date | Time | Event | Orbit |
|---|---|---|---|
| 1975 Sep 9 | 1839:00 | Launch by Titan TC-3 | |
| 1840:52 | St 1 burn | ||
| 1841:02 | SRM sep | ||
| 1843:21 | St 1 cutoff | ||
| 1843:21 | St 1 sep, St 2 burn | ||
| 1843:33 | CSS sep | ||
| 1846:50 | St 2 MECO | ||
| 1846:53 | St 2 sep | ||
| 1847:05 | Centaur MES 1 | ||
| 1849:13 | Centaur MECO 1, 20 min coast | 185? x 185? x 28.6? | |
| 1907:27 | Centaur MES 2 | ||
| 1912:27 | Centaur MECO 2 | 178 x -65940 x 29.3 | |
| 1975 Sep 9 | 1916:07 | Centaur sep | 279259 km miss dist |
| 1975 Sep 9 | 2047:00 | Bioshield cap sep | |
| 1975 Sep 10 | 0314 | Viking pass EL1:4 | |
| 1975 Sep 10 | 0322? | Centaur pass EL1:4 | |
| 1975 Sep 14 | 0010 | Viking leave ELS1 sphere | |
| 1975 Sep 14 | 0132 | Perihelion of post-MC1 orbit | |
| 1975 Sep 14 | 0213 | Perihelion of pre-MC1 orbit | |
| 1975 Sep 14 | 0230? | Centaur leave ESL1 sphere | |
| 1975 Sep 19 | 1.00659 x 1.66949 AU x 2.92 | ||
| 1975 Sep 19 | 1630? | MC1 | 1.00658 x 1.67114 AU x 2.92 |
| 1976 Jul 28 | Approach | 7775 x -26940 x 42.81 | |
| 1976 Jul 28 | 0100 | AMC Approach trim | 1653 x -20782 x 55.18 |
| 1976 Aug 2 | 2007? | Enter Mars sphere | |
| 1976 Aug 7 | 1129:52 | MOI burn 39:35 1.101 km/s | |
| 1209:27 | MOI complete | 27.6h 1519 x ? x 55.0 | |
| 1976 Aug 9 | 1716:00 | MOT1 6s 4.1m/s | 27.32h 1499 x35531 x 55.2 50.4 |
| 1976 Aug 14 | 0831:15 | MOT 2 1.8m/s 3s | |
| 1976 Aug 25 | 1748:29 | MOT3 42.7m/s 78s | |
| 1976 Aug 27 | 2025:38 | MOT4 11.3m/s 19s sync | 24.62h 1489 x 32605 x 55.4 52.2 |
| 1976 Sep 3 | 1920 | Lander sep | |
| 1976 Sep 29 | 0433:20 | MOT5A 5.0m/s | |
| 1976 Sep 30 | 2107:38 | MOT5 342.6m/s | 26.78h 1518 x 34933 x 75.1 63.6 |
| 1976 Dec 14 | Viking Extended Mission | ||
| 1976 Dec 20 | MOT8 | 26.48h 778 x 35350 x 80.1 -60.6 | |
| 1977 Mar 2 | MOT9 | 24.73h 751 x 33464 x 80.2 54.4 | |
| 1977 Apr 18 | MOT10 | 22.73h 723 x 31251 x 80.5 51.9 | |
| 1977 Apr 18 | Survival Automatic Mission | ||
| 1977 Sep 26 | MOT11 | 24.29h 712 x 33015 x 80.3 34.3 | |
| 1977 Oct 9 | MOT12 | 24.22h 594 x 33056 x 80.3 32.6 | |
| 1977 Oct 10 | Deimos pass | ||
| 1977 Oct 12 | Deimos pass | ||
| 1977 Oct 15 | Deimos pass | ||
| 1977 Oct 17? | Deimos pass | ||
| 1977 Oct 22? | Deimos pass | ||
| 1977 Oct 23 | MOT13 | 23.98h 302 x 33080 x 80.3 24.8 | |
| 1978 Mar 3 | Bio base jettison | ||
| 1978 May 31 | Viking Continuation Mission | ||
| 1978 Jul 24 | 0601 | end of ops | |
Viking Lander 2 (VL-2) landed on Mars on 1976 Sep. The biology unit operated until 1977 May 28 and the data storage memory failed on 1979 Nov 19. Low battery voltage on 1980 Apr 12 caused the end of VL-2's mission.
| VL2 | |||
| Date | Time | Event | Orbit |
|---|---|---|---|
| 1976 Sep 3 | 1919:29 | Sep from VO2 | |
| 1926:30 | S+7:01 Deorbit 23 min burn 156m/s | ||
| 1948:46 | S+29:17 end burn | -103 x 31205 x 55.5 | |
| 2228:46 | S+3:09:17 entry 244 km 4.6121km/s -17.08 deg | ||
| 2236:00 | S+3:16:31 Parachute deploy 5.9 km | ||
| Aeroshell base sep 5.0 km | |||
| Aeroshell top sep | |||
| 2237:04 | S+3:17:35 Terminal descent 1.5 km | ||
| 2237:50 | S+3:18:21 Touchdown | ||
| 2244 | Biology PDA lid deploy | ||
| 2255 | First pictures | ||
| 1976 Sep 5 | 1005 | Arm cover eject | |
| 1976 Sep 7 | 1439 | GCMS PDA lid deploy | |
| 1977 May 28 | Biology unit off | ||
| 1980 Apr 12 | end of tx | ||
| 1996 Jul 20 | Renamed Gerald A. Soffen Memorial Station | ||
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