2010-039A
The Advanced EHF program replaces Milstar. LM A2100M. The spacecraft has two small deployable payload wings, a little like small versions of the Milstar, on which antennas are mounted.
Five satellites will be launched. Prime is LMSS/Sunnyvale; propulsion module from LM-MSSC at Stennis. AEHF is operated by AFSPC and acquired by the USAF MCSW, Military Satellite Communications Wing (formerly Milsatcom JPO).
Launch by Atlas 531 with short 5m PLF.
AEHF 2 by Atlas V; AEHF 3 in Apr 2010 by Delta 4M+(5,4)?
Launch mass 6200 kg, BOL mass 4080 kg? or 4400 kg. Size 23.1m span, 9.8m high deployed. Mass in orbit 6169 kg?
The US Air Force's first Advanced EHF communications satellite was launched on Aug 14. AEHF 1 is a Lockheed Martin A2100M satellite with a launch mass of around 6200 kg. The AEHF constellation's SHF and EHF communications payloads will replace the Milstar satellite system launched in the 1990s.
AEHF 1's Lockheed Martin/ULA Atlas V launch vehicle AV-019 was a model 531 variant with three strapon solid motors; the first burn of the Centaur upper stage reached a 167 x 1281 km x 27.8 deg orbit at 1121 UTC. Centaur restart at 1129 UTC pushed AEHF 1 into a 221 x 50179 km x 22.2 deg deployment orbit. Large burns with the liquid bipropellant apogee thruster was intended to raise the orbit initially followed by several months of burns from AEHF 1's Hall-thruster electric propulsion system. However, the bipropellant thruster failed and instead a series of small burns with a lower thrust monopropellant hydrazine engine, using the same hydrazine tank, were needed.
Control by SMC until after checkout in GEO, then to AFSC.
| AEHF | |||
| Date | Time | Event | Orbit |
|---|---|---|---|
| 2010 Aug 14 | 1107 | Launch by Atlas V 531 AV-019 | SLC 41 |
| T+1:31 SRB burnout | |||
| T+1:54 SRB 1-2 sep | |||
| T+1:56 SRB 3 sep | |||
| T+3:27 PLF sep | |||
| T+3:33 CFLR sep | |||
| T+4:17 BECO | |||
| 1111 | T+4:23 Atlas sep | ||
| T+4:33 Centaur MES1 74W 27N | |||
| 1121 | T+14:08 MECO1 | 167 x 1281 x 27.66 | |
| 1129 | T+22:17 MES2 | ||
| 1134 | T+27:37 MECO2 | ||
| 1158 | T+51:00 Centaur sep from AEHF 1 | 222 x 50245 km x 22.24 | |
| 2010 Aug 15 | LAM-1 burn attempt, anomalous shutdown | ||
| Problem with propulsion? | |||
| 2010 Aug 17 | LAM-1b attempt, shutdown | ||
| 2010 Aug 20 | Apogee 10, REA-1 COLA burn | ||
| 2010 Aug 29 | 1400 | Segment 1 REA 1-1 40 min | 428 x 49984 x 21.67 |
| 2010 Aug 29 | Seg 1 burns begin, raise perigee to 950 km | ||
| 2010 Aug 31 | 1325? | REA 1-2 | 589 x 49992 x 21.21 |
| 2010 Sep 2 | 1209? | REA 1-3 | 791 x 49983 x 20.81 |
| 2010 Sep 4 | 1105? | REA 1-4 | 982 x 49981 x 20.36 |
| 2010 Sep 6 | Segment 2, REA raise perigee to 1000 km? | ||
| 2010 Sep 7 | 0157? | REA 2-1 | 1164 x 49994 x 19.96 |
| 2010 Sep 9 | 0120 | REA 2-2 | 1512 x 49985 x 19.35 |
| 2010 Sep 11 | 0049 | REA 2-3 | 2222 x 49975 x 18.23 |
| 2010 Sep 13 | 0138 | REA 2-4 | 3091 x 49976 x 17.01 |
| 2010 Sep 15 | 0310 | REA 2-5 | 3946 x 49985 x 16.00 |
| 2010 Sep 18 | 1520 | REA 2-6 | 4546 x 49981 x 15.37 |
| 2010 Sep 29 | 1027.09 4699 x 49985 x 15.1 | ||
| 2010 Oct 4 | HCT burns | ||
| 2010 Oct 15 | 4733 x 49975 x 15.1 | ||
| 2010 Nov 28 | Segment 3, HCT apogee burns | ||
| 2010 Dec 20 | Segment 4, HCT continuous burn | ||
| 2011 Jan 6 | 1174.15 10069 x 50908 x 10.5 | ||
| 2011 Mar 19 | 1370.15 17531 x 51439 x 8.3 | ||
| 2011 Mar 23?? | 23 hr period | ||
| 2011 Apr 25?? | 25 hr period | ||
| 2011 Apr 26 | 1503.46 22494 x 51696 x 7.2 | ||
| 2011 Jul 22 | 1665.11 33783 x 46531 x 5.4 | ||
| 2011 Sep 2 | 1563.03 35989 x 40481 x 4.8 | ||
| 2011 Sep 18 | 1520.37 35885 x 38955 x 4.7 | ||
| 2011 Sep 20 | Resume thrusting | ||
| 2011 Oct Arrived in GEO | |||
| 2012 Mar | Operational | ||
Payload:
- Milstar II LDR/MDR compatible comms, SHF/EHF
- 20/44 GHz antenna
- 60 GHz crosslink antenna
- Aerojet XR-5 electric propulsion, 4.5 kW Hall thrusters
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