1976-023A
LES 8 and LES 9, derived from the LES 7 design, were tests of satellite survivability with hard low data rate links between command posts and mobile forces. They tested frequency hopping and autonomous attitude control. They were launched as experiment LL-208, part of STP mission P74-1 aboard a Titan IIIC. The satellite was 420 kg, 2.9 m long and 1.2m diameter. The box-shaped main body had the K-band system on the Earth-facing end and the UHF antenna and RTG mast on the zenith end. Planned flight of pulsed plasma thrusters were cancelled in favor of more reliable cold gas thrusters. The MHW RTGs were developed for the Voyager program; three MHW are on each VGR, two on each LES.
The P74-1 truss on which the craft were mounted was developed by TRW. The LES8/9 and truss were integrated with the fairing and then attached to the Transtage; SR11A/B were already integrated with the Transtage. LES 8 and 9 were delivered to an inclined synchronous orbit with i=25 deg (near-ecliptic), since the Titan didn't have the performance to place them in equatorial orbit. After orbit insertion, a Joint Test Program was conducted under the management of AFSC Electronic Systems Div (ESD). The satellites were transferred in 1977 Sep to AFCS (Air Force Communications Service) at Brandywine, Maryland as the SCOPE DAWN program, although spacecraft control remains at LESOC/Lincoln Labs. They were used as part of the UHF net with Marisat, LES 6 and TACSAT 1.
In Feb 1977 the LES 8 and 9 satellites were used for the STRESS experiment to test satellite communications through a barium release cloud, simulating the effects of a nuclear explosion.
From 1986 to 1988 it drifted east, and from 1988 to 1991 in was in the 60-70W region. In Jan-Feb 1991 it was moved back west to 106W, and then was left to drift in the 98-107W region.
| LES 8 | |||
| Date | Time | Event | Orbit |
|---|---|---|---|
| 1976 Mar 15 | 0125 | Launch by Titan IIIC | CC |
| 0129 | Titan Stage 2 burn | ||
| 0133 | Stage 2 cutoff | ||
| 0133 | Stage 2 sep | 148 x 160 x 28.6 | |
| 0240 | Transtage burn 1 | ||
| 0805 | Transtage burn 2 | ||
| LES 8 dispense | |||
| LES 9 dispense | |||
| Payload support structure sep (23G) | |||
| 1976 Mar 16 | Stationkeep burn, reverse drift | ||
| 1976 Mar 19 | Passes LES 9 | ||
| 1976 Mar | JTP phase 1, checkout | ||
| 1976 Mar 30? | JTP phase 2, comm tests | ||
| 1976 Jun | JTP phase 3, LL testing | ||
| 1976 Jul 7 | On station at 110W | ||
| 1976 Sep? | JTP phase 4, DoD/LL tests | ||
| 1976 Oct 4 | End longitude test period, loose drift | ||
| 1977 Jan 24 | 1435.87 35751 x 35812 x 25.2 GEO 106.1W | ||
| 1977 Feb | STRESS experiments | ||
| 1977 Jun 5 | 1436.32 35771 x 35810 x 25.2 GEO 99.1W+0.06W | ||
| 1977 Sep | JTP phase 4 concludes, to AFCS | ||
| 1978 Nov | GEO 106-110W | ||
| 1982 Jun | GEO 106-110W | ||
| 1983 Jan 1 | 1436.24 35776 x 35802 x 24.4 GEO 108.3W+0.04W | ||
| 1984 Jan 3 | 1435.99 35763 x 35805 x 23.9 GEO 109.6W+0.02E | ||
| 1985 Jan 19 | 1436.22 35781 x 35796 x 23.3 GEO 107.6W+0.04W | ||
| 1986 Jan 2 | 1436.01 35782 x 35787 x 22.8 GEO 107.6W+0.01E | ||
| 1986 Oct 26 | 1436.05 35777 x 35794 x 22.2 GEO 106.1W+0.00E | ||
| 1986 Oct 29 | orbit raise | 1435.60 35771 x 35782 x 22.2 GEO 105.7W+0.12E | |
| 1987 Jan 13 | 1435.56 35761 x 35790 x 22.1 GEO 95.3W+0.13E | ||
| 1988 Jan 4 | 1435.87 35766 x 35797 x 21.4 GEO 61.9W+0.05E | ||
| 1989 Jan 2 | 1436.22 35759 x 35818 x 20.7 GEO 64.2W+0.04W | ||
| 1990 Jan 2 | 1435.57 35739 x 35812 x 20.0 GEO 68.6W+0.13E | ||
| 1991 Jan 1 | 1435.97 35738 x 35829 x 19.3 GEO 61.6W+0.02E | ||
| 1991 Jan 5 | 1436.01 35740 x 35829 x 19.3 GEO 61.6W+0.01E | ||
| 1991 Jan 10 | mv out | 1441.36 35833 x 35945 x 19.3 GEO 70.2W+1.3W | |
| 1991 Feb 5 | 1441.45 35832 x 35950 x 19.2 GEO 105.7W+1.3W | ||
| 1991 Feb 11 | mv in | 1436.14 35742 x 35832 x 19.2 GEO 106.1W+0.02W | |
| 1992 Jan 2 | 1435.94 35743 x 35823 x 18.5 GEO 97.7W+0.03E | ||
| 1992 Jul 6 | 1436.11 35739 x 35834 x 18.1 GEO 94.3W | ||
| 1993 Jan 3 | 1436.25 35744 x 35834 x 17.8 GEO 97.9W+0.04W | ||
| 1994 Jan 2 | 1436.00 35747 x 35821 x 17.0 GEO 105.0W+0.02E | ||
| 1995 Jan 3 | 1436.06 35741 x 35831 x 16.3 GEO 94.1W | ||
| 1996 Jan 1 | 1436.22 35746 x 35831 x 15.6 GEO 102.9W | ||
| 1997 Jan 1 | 1435.96 35743 x 35824 x 14.9 GEO 100.4W | ||
| 1998 Jan 1 | 1436.20 35750 x 35826 x 14.1 GEO 95.8W | ||
| 1999 Jan 4 | 1436.09 35694 x 35878 x 13.4 GEO 105.4W | ||
| 2004 Jun 2 | Retired | ||
Payload:
- EHF K-band (36-38 GHz) Earth horn link
- EHF K-band (36-38 GHz) sat-sat crosslink
- Filter electronics, shielding
- MHW RTG's Pu-238 150W
- Single axis gyro
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