Artist's impression of an AEHF-1 satellite
Advanced Extremely High Frequency-1
Mission typeMilitary communications
OperatorUnited States Air Force / United States Space Force
COSPAR ID2010-039A Edit this at Wikidata
SATCAT no.36868
Mission duration14 years (planned)
13 years, 8 months and 17 days (in progress)
Spacecraft properties
ManufacturerLockheed Martin Space
Launch mass6,168 kg (13,598 lb)
Start of mission
Launch date14 August 2010, 11:07:00 UTC
RocketAtlas V 531 (AV-019)
Launch siteCape Canaveral, SLC-41
ContractorUnited Launch Alliance
Orbital parameters
Reference systemGeocentric orbit[1]
RegimeGeosynchronous orbit
AEHF-2 →

USA-214, also known as Advanced Extremely High Frequency-1 or AEHF-1, is a military communications satellite operated by the United States Air Force. It is the first of six satellites to be launched as part of the Advanced Extremely High Frequency program, which will replace the earlier Milstar system.[2]

Satellite description

The USA-214 satellite was constructed by Lockheed Martin Space, and is based on the A2100 satellite bus. The satellite has a mass of 6,168 kg (13,598 lb) and a design life of 14 years.[3] It will be used to provide super high frequency (SHF) and extremely high frequency (EHF) communications for the United States Armed Forces, as well as those of the United Kingdom, the Netherlands, and Canada.[2]


AEHF-1 was launched on an Atlas V.

Though initially scheduled for launch on 30 July 2010, delays with the launch vehicle pushed flight back to 10 August 2010, and finally to 14 August 2010.[4]

USA-214 was launched by United Launch Alliance, aboard an Atlas V 531 flying from Space Launch Complex-41 (SLC-41) at the Cape Canaveral Air Force Station (CCAFS). The launch occurred at 11:07:00 UTC on 14 August 2010,[5] and resulted in the satellite being deployed successfully into a geostationary transfer orbit (GTO) with a perigee of 221 km (137 mi), an apogee of 50,179 km (31,180 mi), and 22.2° Orbital inclination.[6]


The satellite was intended to maneuver from the transfer orbit into which it was launched to its operational geosynchronous orbit by means of a liquid apogee engine (LAE) and several Hall-effect thrusters, a process which normally takes 105 days.[7][8][9] However, the satellite's Liquid Apogee Engine malfunctioned shortly after ignition on both its first burn on 15 August 2010 and a second attempt on 17 August 2010,[10] and it was declared inoperable.[7][11]

To solve the problem, the perigee altitude was raised to 4,700 km (2,900 mi) using twelve firings of the smaller Reaction Engine Assembly thrusters, originally intended for attitude control during LAE maneuvers.[12] From this altitude, the solar arrays were deployed and the orbit was raised toward the operational orbit over the course of nine months using the 0.27 Newton Hall effect thruster, a form of electric propulsion which is highly efficient, but produces very low thrust and is therefore very slow.

The problem with the liquid apogee engine was later blamed on a piece of cloth accidentally left in a fuel line leading up to the engine while the line was taken apart for repair during the manufacture of the satellite. The cloth was likely placed in the line to prevent impurities from entering the fuel line and did not get removed when the line was put back together.[13]

See also


  1. ^ "AEHF 1 (USA 214)". Heavens Above. Retrieved 25 December 2013.
  2. ^ a b "Atlas V AEHF-1 Mission Overview" (PDF). United Launch Alliance. Archived from the original (PDF) on 22 July 2011. Retrieved 17 May 2021.
  3. ^ "AEHF 1, 2, 3, 4, 5, 6". Gunter's Space Page. 4 November 2020. Retrieved 17 May 2021.
  4. ^ "AEHF-1 Launch Delayed". Air Force Magazine. 15 July 2010. Retrieved 26 March 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  5. ^ Ray, Justin (14 August 2010). "Rise and shine: Atlas 5 rocket successfully soars at dawn". Spaceflight Now. Retrieved 16 August 2010.
  6. ^ McDowell, Jonathan (12 August 2010). "Issue 632". Jonathan's Space Report. Retrieved 16 August 2010.
  7. ^ a b Ray, Justin (30 August 2010). "Military satellite relying on backup plan to save itself". Spaceflight Now. Retrieved 31 August 2010.
  8. ^ Butler, Amy (15 November 2010). "Japanese Engine Not AEHF Issue: USAF Official". Aviation Week. Retrieved 29 January 2011.
  9. ^ Butler, Amy (22 November 2010). "USAF: AEHF-1 Engine Failure An Anomaly". Aviation Week. Retrieved 29 January 2011.
  10. ^ Ray, Justin (2 September 2010), Spaceflight Now, Investigators probing what went wrong with AEHF 1 (accessed 14 December 2011)
  11. ^ "Main engine probably not to blame for AEHF-1 trouble". Retrieved 19 October 2010.
  12. ^ Ray, Justin (9 October 2011), Spaceflight Now, Air Force satellite's epic ascent should finish soon (accessed 14 December 2011)
  13. ^ "Delicate rescue saves stranded US$1.7 billion U.S. satellite". Associated Press. 17 March 2012.