Ekspress AM4

Ekspress AM4 was a communications satellite placed into the wrong orbit from a faulty Briz-M rocket stage. This satellite was to be part of the Ekspress series of geostationary communications satellites owned by Russian State Company for Satellite Communications. Proposals were made to reposition the satellite to provide broadband services to Antarctica, but ultimately the decision was made to de-orbit the satellite. On 28 March 2012 the satellite splashed into the Pacific Ocean.[3]

Ekspress AM4

Mission type	Communications
Operator	FGUP
COSPAR ID	2011-045A
SATCAT no.	37798
Mission duration	15 years planned Launch failure
Spacecraft properties
Bus	EADS Astrium
Manufacturer	Eurostar-3000
Launch mass	5,775 kilograms (12,732 lb)
Power	14 kilowatts
Start of mission
Launch date	17 August 2011, 21:25:01 (2011-08-17UTC21:25:01Z) UTC[1]
Rocket	Proton-M/Briz-M
Launch site	Baikonur 200/39
Contractor	Khrunichev
End of mission
Disposal	Deorbited
Decay date	25 March 2012 (2012-03-26)
Orbital parameters
Reference system	Geocentric
Regime	Medium Earth Geostationary planned
Longitude	80° east planned
Perigee altitude	695 kilometres (432 mi)
Apogee altitude	20,239 kilometres (12,576 mi)
Inclination	51.1 degrees
Period	6.04 hours
Epoch	25 August 2011[2]

Launch

The Ekspress AM4 satellite was launched on 18 August 2011 on a Russian Proton rocket from Kazakhstan, which included a Briz-M stage.[4] It was just after launch that the Briz-M stage did not separate from the Ekspress satellite, causing it to fall into the wrong orbit.[5]

Spacecraft

The total mass of the Ekspress AM4 satellite was 5,800 kg, and the spacecraft had 64 transponders. The onboard antennas were capable of broadcasting in the C, K_u, L, and Ka bands. The satellite's orbit was measured at 1,007 by 20,317 km altitude, with an inclination orbit of 51.3 degrees. Though the satellite was placed in the wrong orbit, there was no damage to the satellite, meaning that it became the subject of numerous reuse proposals.

Reuse proposals

One of the most notable reuse proposals came from a company called Polar Broadband Systems, which was established in December 2011. Its objectives were to submit proposals for the reuse of semi-retired and retired satellites for use with communications over the Antarctic. The company notes that it would not have been feasible to build a dedicated satellite for the region as the population would not justify the expense, however Ekspress AM4 would suffice as it could have been maneuvered into the required orbit. There was enough fuel on board for it to be operational for ten years, with giving the Antarctic region 16 hours of broadband access a day. Similarly, Australian company Antarctic Broadband [6] proposed a similar scheme for Antarctic communications, however neither were successful.[7]

Deorbit

Dennis Pivnyuk, chief financial officer of the Russian Satellite Communications Co, informed on 15 March 2012 that the satellite would be decommissioned and deorbited. He stated that the descent phase would start on 20 March, with the spacecraft reentering over the Pacific Ocean around 26 March. The spacecraft was destroyed during reentry on 28 March.[8]

References

1. McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 30 October 2013.
2. McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 30 October 2013.
3. "Second Life for Failed Russian Satellite." Retrieved 1 April 2012
4. Parfitt, Tom (18 August 2011). "Russian satellite missing within hours of takeoff". The Guardian. ISSN 0261-3077. Retrieved 31 December 2018 – via www.theguardian.com.
5. "Repurposing Express-AM4: Mission Possible: Recycling Space Junk into Antarctic Science Treasure." Retrieved 1 April 2012
6. "Antarctic Broadband"
7. "Lost Russian Communications Satellite Found in Wrong Orbit." Retrieved 1 April 2012
8. "Dead Russian Satellite to Fall From Space." Archived 23 February 2013 at Archive.today Retrieved 1 April 2012

External links

• IMS Official provider's site