1998-058A
Atlas flight AC-130 placed the UHF F/O F9 satellite in orbit using a Lockheed Martin Astronautics Atlas IIA with a 14-ft fairing. It took off from Cape Canaveral's Space Launch Complex 36A. The Atlas IIA first stage main (sustainer) engine is the Boeing Rocketdyne RS-56SA, based on the RS-27 used in Delta. Wrapped around the main engine section is a booster section with two very similar RS-56BA engines. The booster engine cutoff (BECO) was at T+2:45 (i.e. 2min 45s after launch), followed 3s later by separation of the heavy booster package with its two engines. The sustainer engine cutoff (SECO) was at T+4:35.
After separation of the Atlas stage at T+4:37, the Centaur II second stage takes over. Centaur is a liquid hydrogen fuelled stage using two Pratt and Whitney RL10A-4-1 engines. At T+9:53 the Centaur shut down putting the vehicle in a 168 x 1090 km x 28.9 deg elliptical parking orbit. After coasting around the orbit, Centaur reignited at T+22:23 for about one minute until its fuel was almost depleted. and then at T+27:03 separated from the payload. Target orbit was at least a 286 x 26733 km x 27.0 deg orbit, with an apogee 10000 km below geostationary. This shortfall is to be made up by the Marquardt R-4D bipropellant liquid apogee motor on the Hughes HS-601 satellite payload.
The payload is UHF F/O F9, a Block III UHF Follow-On comsat for the US Naval Space Command. Earlier UHF F/O satellites were launched by Atlas II, which has now been retired. The satellite carries UHF and EHF transponders for naval communications, and a Ka-band Global Broadcast Service video relay package. Launch mass is 3200 kg, dropping to around 1550 kg once geostationary orbit is reached. Dry mass of the satellite is probably around 1200-1300 kg, but I haven't seen a figure on this. UHF F/O F9 was checked out in a slightly elliptical synchronous orbit over 170-175W and then in Jan 1999 placed over the Atlantic Ocean for operational service.
Although operated by the Navy, the payload is considered a joint Dept. of Defense asset with support for all services. UHF satellites were operated by US Space Command 3 SOPS/Schriever AFB until 1999 Jun 15, when control passed to NAVSOC/Pt Mugu.
|
| UHF 9 |
| |
|
| Date | Time | Event | Orbit |
|---|
|
| 1998 Oct 20 | 0719 | Launch by Atlas II AC-130 | SLC 36A |
| | | T+2:45 BECO |
|
| | | T+2:48 Booster sep |
|
| | | T+04:34 SECO |
| | | T+04:36 Atlas sep |
| | | T+04:53 MES 1 |
| | 0728 | T+09:53 MECO1 | 168 x 1090 28.9 |
| | 0741 | T+22:23 MES2 |
| | 0742 | T+23:36 MECO2 | 465.2 286 x 26733 x 27.0 |
| | 0746 | T+27:03 Centaur sep | 465.1 287 x 26726 x 27.0 |
| | | T+1:07:44 Depletion burn | 461.0 279 x 26499 x 27.0 |
| 1998 Oct 20 | | | 448.35 272 x 25780 x 27.0 |
| 1998 Oct 21 | 1340? | LAM-1 |
| 1998 Oct 22 | | | 533.47 269 x 30552 x 26.9 |
| 1998 Oct 23 | 2340? | LAM-2 |
| 1998 Oct 23 | | | 790.82 7126 x 36772 x 14.8 |
| 1998 Oct 27 | 0430? | LAM-3 |
| 1998 Oct 27 | | | 1428.51 34478 x 36798 x 6.3 GEO 175.3W+1.9E |
| 1998 Oct 28 | | | 1436.55 34808 x 36782 x 6.1 GEO 173.8W+0.1W |
| 1998 Nov 5 | | | 1436.18 34810 x 36769 x 6.0 GEO 172.8W+0.03W |
| 1998 Dec 3 | | | 1436.04 34815 x 36754 x 6.0 GEO 170.6W |
| 1998 Dec 18 | | | 1435.95 34815 x 36751 x 6.0 GEO 172.2W |
| 1998 Dec | | Move out |
| 1999 Jan | | In service at 22W |
| 1999 Jan 19 | | | 1436.09 35774 x 35798 x 5.9 GEO 22.5W |
| 1999 Jul 26 | | | 1436.05 35768 x 35803 x 5.6 GEO 22.5W |
