AngoSat 1


AngoSat 1
Mission typeCommunications
OperatorAngola Ministry of Telecommunication and Information Technology
COSPAR ID2017-086A
SATCAT no.43087
Mission duration15 years (planned)
(contact lost permanently
after 3 days in orbit)
Spacecraft properties
SpacecraftAngoSat 1
BusUSP Bus
ManufacturerRKK Energia
Launch mass1647 kg
Start of mission
Launch date26 December 2017
19:00:00 UTC [1]
RocketZenit-3F / Fregat-SB
Launch siteBaikonur, Site 45/1
Entered serviceNever (failure in orbit)
End of mission
DisposalLost contact
Last contact29 December 2017 [2]
Orbital parameters
Reference systemGEO
Longitude14° E (planned)
Frequency7 Ku band and 16 C band
AngoSat 2 →

AngoSat 1 was a geostationary communications satellite operated by Angosat and built by the Russian company RKK 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.[2] The satellite suffered a power problem in the first hours of flight and lost contact with ground control. After the power problem, contact was established with the satellite, but ultimately the satellite did not recover, and contact was lost permanently 3 days into the mission. After repeated failures to establish contact in the following weeks/months, the satellite was declared lost. Russia will build a replacement satellite called AngoSat 2 to be delivered in late 2019.[3]


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, 19:00:00 UTC.[1][4] The satellite was financed by Rosoboronexport with a 286.2 million euro loan.[5]


AngoSat 1 is based on RKK Energia's USP Bus of Gazprom Space Systems' Yamal-heritage. Airbus Defence and 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.[6] The AngoSat 1 payload is composed of 16 C band and 6 Ku band transponders supplied by Airbus Defence and Space.[7]

Demise and replacement

On 26 December 2017, RKK Energia announced contact with AngoSat 1 was lost while the satellite was moving to its geostationary orbit due to low onboard batteries.[8][9] On 27 December 2017, communications had been restored with the satellite after the satellite was properly aligned with the sun to allow the onboard batteries to recharge,[8][10] but it is unclear whether the satellite could fully recover its operability.[citation needed] On 29 December 2017, Roscosmos and satellite manufacturer RKK Energia confirmed that its onboard systems were in good health.[11]

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. RKK Energia issued a press release on 15 January 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.[12][8] 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.[3]

The Russian government and RKK Energia have agreed to finance and provide a replacement satellite called AngoSat 2, with upgraded capabilities. The new satellite was 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.[3]

In January 2020, the Angosat-2 project's readiness status was unclear; rumors were published that the construction of the satellite had been taken away from RKK Energia and given to ISS Reshetnev. At the same time, Angolan press reported the satellite being 50% ready,[13] for a launch in December 2021.[14]


  1. ^ a b Graham, William (26 December 2017). "Zenit rocket launches with AngoSat-1". Retrieved 26 December 2017.
  2. ^ a b Clark, Stephen (2 December 2017). "Communications restored with newly-launched Angolan satellite". Spaceflight Now. Retrieved 5 September 2018.
  3. ^ 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.
  4. ^ Krebs, Gunter Dirk. "AngoSat 1". Gunter's Space Page. Retrieved 20 May 2017.
  5. ^ "Angola: U.S.$300 Million Invested in Angosat-1 Project". Angola PRESS. 21 February 2016. Retrieved 19 July 2016.
  6. ^ "AngoSat 1".
  7. ^ "Angosat 1". Satbeams. Retrieved 19 July 2016.
  8. ^ a b c Zak, Anatoly. "Zenit successfully delivers Angosat-1". Retrieved 10 January 2018.
  9. ^ Henry, Caleb (27 December 2017). "Contact Lost with Angosat-1, Manufacturer Says". Retrieved 27 December 2017.
  10. ^ "Russian Space Agency Says Contact Regained With Angolan Satellite". RadioFreeEurope/RadioLiberty. 28 December 2017. Retrieved 29 December 2017.
  11. ^ Henry, Caleb (29 December 2017). "Angosat-1 communications restored after post-launch glitch -". Retrieved 29 December 2017.
  12. ^ "No Signs of Life from Russian-built AngoSat, Troubleshooting to Resume in April". Spaceflight101. 15 January 2018. Retrieved 15 January 2018.
  13. ^ "The Angosat-2 communications satellite".
  14. ^ - 1 May 2020

External links

  • SATBEAMS page
  • AngoSat official page