1973-039A
Because of the problem of terrestrial radio interference, the second RAE, RAE B, was designed to make its observations in lunar orbit, shielded from Earth while it skimmed above the lunar farside. The spacecraft had a velocity control thruster to refine the lunar orbit.
RAE 2 (Explorer 49) was launched at 1413 on 1973 Jun 10 by a Delta 1913 from Cape Kennedy. The Delta stage ignited at 1417:30 and cut off at 1422:30 to place the combination in parking orbit. At 1425 the Delta reignited for 29s to enter a 107.8 min, 182 x 2074 km x 29.3 deg orbit. At 1428 the Star 37D third stage ignited for the 44s translunar injection burn, entering a 182 x 390244 km x 29.1 deg orbit. RAE 2 separated from the Star 37D at 1430. The VCS was used to make a midcourse correction at 1528 on Jun 11. The TE-M-479 (Star 17) solid motor fired at 0721 on Jun 15 to insert RAE 2 in a 241 min, 1123 x 1334 km x 38.3 deg lunar orbit. The Star 17 was jettisoned on Jun 18, and the same day the VCS fired to lower the orbit to 221.2 min, 1053 x 1064 km x 38.7 deg. The 37m dipole antenna was extended on Jun 20.
Another object was cataloged in lunar orbit, probably implying the VCS was also ejected after use.
It was reported in Jun 1973 that on Jul 4 the dipole would be retracted, the VCS used to adjust the orbit, and the two main V antennas would be deployed first to 183m, and then a week later to 229m. Total span is 400m. RAE also has a 190m stabilization boom.
RAE 2 operated in lunar orbit until 1977 Apr 30. After that, engineers performed end-of-life tests retracting and extending the antennas. It probably impacted the lunar surface later in 1977. Orbit according to an internal document was 1058 x 1070 km x 59 deg with a 222 min period; this is presumably the first orbit after VCS sep.
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| Explorer 49 |
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| Date | Time | Event | Orbit |
|---|
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| 1973 Jun 10 | 1413:00 | Launch by Delta 1913 | CK LC17B |
| | | T+0:38 SRM 4-9 burnout |
| | | T+0:39 SRM 1-3 on |
| | | T+1:17 SRM 1-3 out |
| | | T+1:25 SRM 1-9 sep |
| | | T+4:29 MECO |
| | | T+4:33 VECO |
| | | T+4:36 St 1 sep |
| | 1417:41 | T+4:41 SES-1 |
| | | T+4:55 Fairing sep |
| | 1422:31 | T+9:31 SECO-1 |
| | 1425:57 | T+13:57 SES-2 29s |
| | 1426:28 | T+14:28 SECO-2 | 182 x 2074 x 29.3 |
| | | T+15:02 Spinup |
| | 1428:05 | T+15:05 Stage 2 sep |
| | 1428:19 | T+15:17.9 Star 37D burn 44s |
| | 1429:03 | T+16:02.7 Star 37D burnout |
| | 1430:43 | T+17:43 Star 37D separation | 182 x 390244 x 29.1 |
| | 1430:45 | T+17:45 Star 37D release yo weight |
| 1973 Jun 11 | 0600? | Pass EL1:4 |
| 1973 Jun 11 | 1528 | VCPS TCM |
| 1973 Jun 13 | 0600? | Enter lunar sphere |
| 1973 Jun 15 | 0721 | Star 17 burn 22s LOI | 241.0 1123 x 1334 x 61.4 |
| 1973 Jun 18 | 0725? | Star 17 sep |
| | | Despin to 12 rpm (ACS) |
| | | VCPS lower orbit to avoid LIM | 221.2 1053 x 1064 x 61.4 |
| 1973 Jun 20 | | 37m dipole extended |
| 1973 Jul 4 | | Retract dipole? |
| 1973 Jul 9 | | Final orbit trim |
| 1973 Jul 9? | | VCPS separated |
| 1973 Jul | | Deploy libration damper |
| 1973 Jul 12 | | Deploy to 183m |
| | | Experiment turn on |
| 1973 Jul 29 | | Begin first lunar shadow period |
| 1973 Oct 26 | | End first shadow period |
| 1973 Nov 8 | | Upper V extension to 200m |
| 1973 Nov 14 | | Upper V deploy to 229m |
| 1974 Jan 3 | | Begin second lunar shadow period |
| 1974 Jan 31 | | | 222.0 1059 x 1071 x 62.0 |
| 1974 Mar 22 | | End second shadow period |
| 1974 Jun 10 | | Begin third shadow period |
| 1974 Aug 28 | | End third shadow period |
| 1974 Oct 11 | | One lower-V boom extended to 229m |
| 1974 Nov 6 | | Second lower-V boom extended to 229m |
| 1974 Nov 17 | | Fourth shadow period |
| 1975 Feb 1 | | End shadow period 4 |
| 1975 Apr 21 | | Shadow period 5 |
| 1975 Jul 1 | | Begin new-moon-intensive 50-percent data coverage |
| 1975 Jul 9 | | End shadow period 5 |
| 1975 Dec 24 | | Resume full time coverage |
| 1976 Apr 17 | | Reduce to 50 percent coverage again |
| 1976 Oct 19 | | Resume full time coverage |
| 1977 Apr 30 | | End of ops |
