Ekspress

Ekspress (Russian: Экспресс meaning Express), is a series of geostationary communications satellites owned by Russian State Company for Satellite Communications. The first satellite of this kind was launched on October 13, 1994. The satellites are produced by the company ISS Reshetnev.

Overview

The Ekspress series of communication satellites (industry code 11F639) was developed by the satellite company NPO PM as a replacement for the old Gorizont series of comsats. The first satellite of the series, Ekspress 1, was launched in 1994. It had a mass of 2.5 tons, 17 channels and an operational lifetime of at 5–7 years.

Starting in the mid-1990s, NPO PM started to make significant effort to close the technology gap between Russian and Western communication satellites.[1] Cooperation with the French company Alcatel (now Thales Alenia Space) was begun in 1995.[2] The first satellite of a new second series, Ekspress A-1, had 12 Alcatel-built transponders. It was lost in a rocket failure in 1999, but a replacement, Ekspress A-2 was successfully launched in March, 2000.

A major improvement was the Ekspress AM version, first launched in 2003. It has an operational lifetime of 12–15 years and is able to carry 38 channels, including digital TV, radio, broadband and internet.[3] The launch of the Ekspress AM-3 spacecraft in June, 2005 completed the modernization of Russia's communications satellite network.[4]

Other versions of include the Ekspress 2000, which has a mass of 3.2 tonnes. It has up to 60 transponders, power of 25 kW and a lifetime of 15 years. Satellites using this platform are called the Ekspress AT series and the Ekspress AM30 and AM40 series. Ekspress 1000 is smaller than the 2000 version; 700 kg to 1,400 kg, 10 to 12 transponders, 2 kW of power and a lifetime of 15 years. Satellites based on Ekspress 1000 are called Ekspress AK or in its navigational version GLONASS K.[1]

The developer NPO PM later changed its name to ISS Reshetnev. From 1999 to 2005, nine Ekspress-A and Ekspress-AM satellites were manufactured by the company.[5]

On August 28, 2008 Ekspress-AM1 switched to DVB-S2 broadcasting system and became the first DVB-S2 satellite in CIS countries.[6]

The Ekspress-AM4 satellite was launched on August 17, 2011, but an anomaly with the Proton-M/Briz-M rocket left it in a useless orbit.[7][8] The satellite was intentionally deorbited March 26, 2012,[9][10] despite proposals to place the satellite into a higher-inclination orbit to provide coverage of the Antarctic.[11] The Ekspress-MD2 satellite was lost in a similar failure in August 2012, when the Briz-M failed at the start of its third burn.

Satellites

Between 2000 and 2015, the following Ekspress satellites were launched. All launched were conducted from Baikonour Cosmodrome using the Proton rocket.[3]

On 29 March 2006, the AM11 was struck by an unknown object which rendered it inoperable. Luckily, the engineers had enough time in contact with the spacecraft to send it to a parking orbit out of GEO.[12]

The Ekspress AM4R was launched 16 May 2014 on a Russian Proton M launch vehicle. The launch vehicle exploded 540 s into the flight, shortly before the end of the third-stage engine firing. Ekspress AM4 was a total loss.[13]

The Ekspress AM8 was launched successfully on 14 September 2015.[14] It uses the Ekspress-1000NTB bus.

References

  1. 1 2 Harvey, Brian (2007). The Rebirth of the Russian Space Program: 50 Years After Sputnik, New Frontiers. Springer. p. 277. ISBN 978-0-387-71354-0.
  2. ↑ "Thales Alenia Space And NPO-PM To Finalize An Industrial Cooperation Agreement". Space Mart. 2007-12-11. Retrieved 2009-05-19.
  3. 1 2 3 Harvey, Brian (2007). The Rebirth of the Russian Space Program: 50 Years After Sputnik, New Frontiers. Springer. p. 86. ISBN 978-0-387-71354-0.
  4. ↑ Zak, Anatoly. "Express communications spacecraft". Russianspaceweb.com. Retrieved 2009-06-21.
  5. ↑ "Achievements in space activity". NPO PM.
  6. ↑ "Сетьтелеком перевел действующую сеть на стандарт DVB-S2". 2008-08-28. Retrieved 2008-08-28.
  7. ↑ "Russia loses contact with new satellite". RIA Novosti. 18 August 2011. Archived from the original on 19 August 2011. Retrieved 19 August 2011.
  8. ↑ Second Life for Failed Russian Satellite? (23 March 2012)
  9. ↑ "Satellite to burn in atmosphere above Pacific". March 25, 2012.
  10. ↑ "Russia Intentionally Crashes Failed Express AM4 Satellite". March 27, 2012.
  11. ↑ Gramling, Carolyn (March 23, 2012). "Second Life for Failed Russian Satellite?". Archived from the original on 2012-03-27.
  12. ↑ "Notification for Express-AM11 satellite users in connection with the spacecraft failure." Russian Satellite Communications Company, 19 April 2006.
  13. ↑ Another Disaster for Russia’s Space Workhorse, Popular Mechanics, 16 May 2014, accessed 16 May 2014.
  14. ↑ Proton rocket takes off with Express AM8 communications bird, Spaceflight Now, 14 September 2015, accessed 6 March 2016
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.