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AngoSat 1 was a geostationary communications satellite operated by Angosat and built by the Russian company RSC Energia. It was the first communications satellite of Angola, designed for a 15-year mission to deliver television, Internet, and radio services to Angola and other territories.[3] The satellite suffered a power problem in the first hours of flight, and was declared lost after repeated failures to establish contact. Russia will build a replacement satellite called AngoSat 2 to be delivered in late 2019.[4]

AngoSat 1
Mission typeCommunication
COSPAR ID2017-086A
SATCAT no.43087Edit this on Wikidata
Spacecraft properties
SpacecraftAngoSat 1
BusUSP Bus
ManufacturerRSC Energia
Launch mass1,550 kg (3,420 lb)
Start of mission
Launch date26 December 2017, 19:00 UTC[1]
RocketZenit-3F / Fregat-SB
Launch siteBaikonur Site 45/1[2]
Entered serviceNever
End of mission
DisposalLost contact
Last contact29 December 2017[3]
Orbital parameters
Reference systemGEO
LongitudeDrifitng (13° E planned)[3]
Frequency44 equivalent Ku band and 16 trp C band


The project was born out of a 2009 agreement between the governments of Angola and Russia, and work started in 2012. The spacecraft was originally supposed to be launched along the Energia 100 satellite on a Zenit-3SL with SeaLaunch in 2016, but political tensions following the annexation of Crimea and SeaLaunch legal issues made the use of the Ukrainian launcher uncertain. Consequently, the launch was first moved to an Angara A5 / Blok DM-03 configuration, and finally back to a Zenit-3F version which was launched from Baikonur Cosmodrome on 26 December 2017, 19:00 UTC.[1][2] The satellite was financed by Rosoboronexport with a 286.2 million euro loan.[5][6]


AngoSat 1 is based on RKK Energiya's USP Bus of Gazprom Space Systems' Yamal-heritage. Airbus Defence & Space (formerly Astrium) provides the payload. The satellite is designed for direct insertion into the geostationary orbit by the launch vehicle upper stage and therefore does not feature an apogee engine.[7] The AngoSat 1 payload is composed of 16 C band and 6 Ku band transponders supplied by Airbus Defense and Space.[8]

Demise and replacementEdit

On December 26, RCS Energia announced contact with AngoSat 1 was lost while the satellite was moving to its geostationary orbit due to low onboard batteries.[9][10] On December 27, communications had been restored with the satellite after the satellite was properly aligned with the sun to allow the onboard batteries to recharge,[9][11] but it is unclear whether the satellite could fully recover its operability.[12] On December 29, Roscosmos and satellite manufacturer Energia confirmed that its onboard systems were in good health.[13]

In the days after the contact was regained with AngoSat-1, the satellite continued drifting westward, according to NORAD data. But independent observers became alarmed, when by mid January, the Angosat had passed over its operational point without any visible attempt to slow down and stop its drift. RSC Energia issued a press release on January 15, 2018, disclosing that the telemetry from the satellite had allowed to reveal a problem in the Angosat's power supply system. The company stated that the spacecraft would leave the range of ground control stations before any additional troubleshooting tasks can be attempted.[14][9] Since the satellite left the communications range of the mission control center in Korolev, the next attempt to contact the satellite and correct the problem was attempted in April 2018. The satellite failed to respond to signals, and was considered lost.[4]

The Russian government and RSC Energia have agreed to finance and provide a replacement satellite called AngoSat 2, with upgraded capabilities. The new satellite is expected to be completed within 18 months and delivered towards the end of 2019. In the meantime, Russia will loan Angola equivalent communications relay capacity on its existing satellite fleet.[4]

See alsoEdit

  1. ^ a b Graham, William (26 December 2017). "Zenit rocket launches with AngoSat-1". Retrieved 26 December 2017.
  2. ^ a b Krebs, Gunter Dirk. "AngoSat 1". Gunter's Space Page. Retrieved 2017-05-20.
  3. ^ a b c Clark, Stephen (2 December 2017). "Communications restored with newly-launched Angolan satellite". Spaceflight Now. Retrieved 5 September 2018.
  4. ^ a b c Blau, Patrick (27 April 2018). "Russia gives up on Silent AngoSat-1, Promises Replacement Satellite to Angola". Spaceflight 101. Retrieved 5 September 2018.
  5. ^ "Lançamento de satélite angolano volta a ser adiado, agora para 2017" [Launch of Angolan satellite delayed again, now to 2017] (in Portuguese). Radio Voz da Rusia. 2014-04-12. Archived from the original on 2015-11-19. Retrieved 2016-07-19. Cite uses deprecated parameter |dead-url= (help)
  6. ^ "Angola: U.S.$300 Million Invested in Angosat-1 Project". Angola PRESS. 21 February 2016. Retrieved 2016-07-19.
  7. ^
  8. ^ "Angosat 1". Satbeams. Retrieved 19 July 2016.
  9. ^ a b c Zak, Anatoly. "Zenit successfully delivers Angosat-1". Retrieved 10 January 2018.
  10. ^ Henry, Caleb (27 December 2017). "Contact Lost with Angosat-1, Manufacturer Says". Retrieved 27 December 2017.
  11. ^ "Russian Space Agency Says Contact Regained With Angolan Satellite". RadioFreeEurope/RadioLiberty. 28 December 2017. Retrieved 29 December 2017.
  12. ^ "Restablecen la comunicación con el satélite angoleño AngoSat-1" (in Spanish). Sputnik. 28 December 2017. Retrieved 28 December 2017.
  13. ^ Henry, Caleb (29 December 2017). "Angosat-1 communications restored after post-launch glitch -". Retrieved 29 December 2017.
  14. ^ "No Signs of Life from Russian-built AngoSat, Troubleshooting to Resume in April". Spaceflight101. 15 January 2018. Retrieved 15 January 2018.

External linksEdit