On-orbit satellite servicing


On-orbit satellite servicing refers to refueling or repairing space satellites while in orbit.[1]

New commercial interest in on-orbit servicing of satellites is in large part due to the decreased costs of launching commercial satellites and the rise of low orbit, rather than geostationary, satellites for which servicing costs less.[2]


Although servicing of satellites has been theoretically considered since the early days of humans attaining the capability of spaceflight, little of it was done in the earliest decades.

The term is usually thought of as meaning autonomous or telerobotic servicing of a satellite by robotic spacecraft, but can also mean servicing that occurs by human astronauts, such as repeated and regular servicing of the International Space Station (ISS) from 1998 to the present day.

The first orbital repair was made by James van Hoften and George Nelson in 1984 during their mission to Solar Maximum Mission (SMM) satellite.

One famous sequence of servicing a satellite by astronauts was the several flights of the Space Shuttle to the Hubble Space Telescope (HST) in 1993–2009 for manual (human-assisted) subsystem-replacement to repair or extend the life of the HST. The five Hubble Space Telescope servicing missions were STS-61 in 1993, STS-82 in 1997, STS-103 in 1999, STS-109 in 2002, and STS-125 in 2009.

Orbital Express was a space mission managed by the United States Defense Advanced Research Projects Agency (DARPA) and a team led by engineers at NASA's Marshall Space Flight Center (MSFC). The Orbital Express program was aimed at developing "a safe and cost-effective approach to autonomously service satellites in orbit".[3] The system consisted of two spacecraft: the ASTRO servicing satellite, and a prototype modular next-generation serviceable satellite; NEXTSat. The mission launched from Cape Canaveral Air Force Station on 8 March 2007, aboard an Atlas V expendable launch vehicle.[4][5] The launch was part of the United States Space Force Space Test Program STP-1 mission.[6]

A collaboration was initiated in 2012 by the Defense Advanced Research Projects Agency — called DARPA Phoenix — with the aim to recycle retired satellite parts into new on-orbit satellite assets, principally focused on satellites in the geosynchronous Clarke Belt. The project was initiated in July 2012 with plans for system launches no earlier than 2016.[7][8] At the time, small satellite tests in low Earth orbit were projected to occur as early as 2015.[9] Although a number of system elements were designed and tested, the U.S. government-funded development program was not continued after 2015.

Another collaboration was initiated in 2017 by DARPA between certain researchers and U.S. government contractors to develop rules for the future commercial use of in-orbit satellite repair.[10] Although commercial launches to space are regulated by government agencies, satellite servicing protocols have not yet been developed.[10]

In 2019, MEV-1, a satellite built by SpaceLogistics. MEV-1 was designed as a servicing satellite for only one of SpaceLogistics' Intelsat 901 satellites, allowing the lifetime of the satellite to be extended by five years.[11][clarification needed] Following the success of that mission, SpaceLogistics was contracted by the U.S. government to study the possibility of servicing U.S. national security satellites.[12]

See also


  1. ^ "On-orbit satellite servicing: The next big thing in space?". SpaceNews. 17 November 2017. Retrieved 4 August 2020.
  2. ^ "Why the Market is Ready for On-Orbit Satellite Servicing – Via Satellite -". Satellite Today. 13 February 2018. Retrieved 4 August 2020.
  3. ^ "Boeing Integrated Defense Systems – Orbital Express". Boeing. Archived from the original on 12 May 2006.
  4. ^ "Look Ma! No (Human) Hands!". NASA. 5 March 2007. Archived from the original on 27 August 2009. Public Domain This article incorporates text from this source, which is in the public domain.
  5. ^ "Orbital Express Launches Successfully". NASA. Archived from the original on 14 January 2010. Public Domain This article incorporates text from this source, which is in the public domain.
  6. ^ "Orbital Express Space Operations Architecture". DARPA. Archived from the original on 13 March 2007. Public Domain This article incorporates text from this source, which is in the public domain.
  7. ^ Ferster, Warren (17 May 2013). "DARPA Cancels Formation-flying Satellite Demo". SpaceNews. Archived from the original on 1 November 2013. Retrieved 1 November 2013.
  8. ^ Graham Warwick (23 January 2013). "Darpa Touts Progress On GEO Satellite Recycling Concept". Aviation Week. Archived from the original on 1 May 2013. Retrieved 25 January 2013.
  9. ^ Gruss, Mike (21 March 2014). "DARPA Space Budget Increase Includes M for Spaceplane". SpaceNews. Archived from the original on 24 March 2014. Retrieved 24 March 2014.
  10. ^ a b Erwin, Sandra (25 November 2017). "On-Orbit Satellite Servicing: The Next Big Thing in Space?". SPACE.com. Retrieved 4 August 2020.
  11. ^ "Investment Perspectives: On-Orbit Satellite Servicing Markets Continue to Evolve". issnationallab.org. Retrieved 4 August 2020.
  12. ^ Strout, Nathan (27 February 2020). "Is this the beginning of on orbit satellite servicing?". C4ISRNET. Retrieved 4 August 2020.