Space Surveillance Telescope


Space Surveillance Telescope
SST in Australia.png
Space Surveillance Telescope
Alternative namesSST Edit this at Wikidata
Location(s)Exmouth, Western Australia, AUS
Coordinates21°53′44″S 114°05′24″E / 21.89566938°S 114.08989072°E / -21.89566938; 114.08989072Coordinates: 21°53′44″S 114°05′24″E / 21.89566938°S 114.08989072°E / -21.89566938; 114.08989072 Edit this at Wikidata
Observatory code G45 Edit this on Wikidata
First light2011, 2020 Edit this on Wikidata
Telescope styleoptical telescope Edit this on Wikidata
Diameter3.5 m (11 ft 6 in) Edit this at Wikidata
Space Surveillance Telescope is located in Earth
Space Surveillance Telescope
Location of Space Surveillance Telescope
Related media on Wikimedia Commons

The Space Surveillance Telescope (SST) is a military telescope for detecting, tracking and cataloguing satellites, near-earth objects and space debris.

SST achieved first light in 2011 at the White Sands Missile Range, New Mexico, United States. In 2017, SST was dismantled and moved to the Harold E. Holt Naval Communication Station, Exmouth, Western Australia.[1][2] From there it will observe the Southern Celestial Hemisphere and collect data for the US Space Surveillance Network. SST achieved first light in Australia on March 5, 2020.[3] SST will be ready for observations again in 2022, operated by the Royal Australian Air Force, 1 Remote Sensor Unit under the command and control (C2) of the U.S. Space Force.[2][4][5][6]


SST enables the military to better track and identify objects and threats in space including space debris, as well as predict and avoid potential collisions.[7] Whether it is space traffic management or the protection of critical space-based capabilities, SST will improve the ability to maintain real-time awareness of the space domain to facilitate the broader needs of both the U.S. and Australia.[8] The discovery and tracking of space debris is noted as a growing problem in the 21st century. One problem is that among the 20-30 thousand large objects in orbit that are tracked, and an estimated 100 million debris as small as paint flecks, it is difficult to find objects that are harder to track than the big objects, but big enough to be harder to shield against if they collide with a space asset.[9] Even paint flecks are known to cause damage because of the extreme speeds at which objects travel in orbit.[9] In other words, there are objects too big to easily shield against, but too small to track.[9] Another concern is the Kessler syndrome, a chain reaction of collisions, creating far more space debris dangerous for working satellites.[10] Another concern are near-Earth asteroids, and the SST can detect these objects as part of its mission.[11]

Earth from space, surrounded by small white dots
A computer-generated image representing space debris as could be seen from high Earth orbit. The two main debris fields are the ring of objects in geosynchronous Earth orbit (GEO) and the cloud of objects in low Earth orbit (LEO).
Space Surveillance Telescope


The SST was sponsored by DARPA and designed by the Massachusetts Institute of Technology Lincoln Laboratory.

SST has a 3.5 meter (138″) aperture mirror.[12][13][14] Two noted design features include a Mersenne-Schmidt type optics and curved CCD.[15] The large curved focal surface array sensors are considered to be an innovative design. It encompasses improvements in detection sensitivity, has short focal length, wide field of view, and improvements in step-and-settle abilities. [note 1]

SST detects, tracks, and can discern small, obscure objects, in deep space with a "wide field of view system". It is a single telescope with the dual abilities. First the telescope is sensitive enough to allow for detection, also, of small, dimly lit objects (low reflectivity). Second it is capable of quickly searching the visible sky. This combination is a difficult achievement in a single telescope design.[16][17]

It is a Mersenne-Schmidt design with an F/1.0 aperture and a 3.5 meter primary mirror. It uses an array of charge-coupled device (CCD) sensors, arranged on a curved focal plane array. The SST mount uses an advanced servo-control technology, that makes it one of the quickest and most agile telescopes of its size. It has a field of view of 6 square degrees and can scan the visible sky in 6 clear nights down to apparent magnitude 20.5. These features allow the system to conduct multiple searches throughout the night, including the entire geostationary belt within its field.

As a telescope system, it can give precise locations of discovered objects, extrapolate the course of the object, and indicate the objects stability.[16][17][18]

The SST is notable in the number of observations it makes and is currently listed by the Minor Planet Center as the world record holder for making the most observations in a single year. In 2015 it made a record 6.97 million observations, significantly more than any other telescope, including Pan-STARRS which is currently in second place, having recorded 5.25 million observations in its best year so far (2014).[19]

See also


  1. ^ "U.S. Air Force takes control of the Space Surveillance Telescope ahead of Australian move". Digital Trends (in American English). 2016-10-22. Retrieved 2018-01-27.
  2. ^ a b Erwin, Sandra (2020-04-23). "U.S. Space Force deploying surveillance telescope in Australia". SpaceNews. Retrieved 2020-04-24.
  3. ^ "The Space Surveillance Telescope in Western Australia captures its first image | MIT Lincoln Laboratory". Retrieved 2021-08-17.
  4. ^ "Exmouth telescope facility takes next step". The West Australian. 2019-05-23. Retrieved 2019-06-08.
  5. ^ "CASG takes over space surveillance telescope - Australian Defence Magazine". Retrieved 2019-10-10.
  6. ^ Defence, Department of (2021-07-07). "Keeping an eye on space traffic". Retrieved 2021-08-19.
  7. ^ Defence, Department of (2020-04-24). "Space Surveillance Telescope captures first images of space". Retrieved 2021-08-19.
  8. ^ "Space Surveillance Telescope Sees First Light: through US & Australian Partnership". United States Space Force (in American English). Retrieved 2021-08-19.
  9. ^ a b c "Space agencies join forces to tackle problem of small debris in low Earth orbit" (in American English). 2018-01-19. Retrieved 2018-01-27.
  10. ^ "Space Junk Could Cause Catastrophic Satellite Collisions, Making Space Travel Impossible". International Business Times. 2017-04-27. Retrieved 2018-01-27.
  11. ^ Davenport, Christian. "Pentagon's new telescope is designed to track space junk, watch out for asteroids". (in American English). Retrieved 2018-01-27.
  12. ^ "Space Surveillance Telescope to Provide Enhanced View of Deep Space" (Press release). DARPA. Archived from the original on 15 April 2011. Retrieved 12 April 2011.
  13. ^ Dickey Zakaib, Gwyneth (2011). "Telescope will track space junk". Nature. doi:10.1038/news.2011.254. Retrieved 22 April 2011.
  14. ^ Ackermann, Mark R.; McGraw, John T. "Large-Aperture, Three-Mirror Telescopes for Near-Earth Space Surveillance: A Look from the Outside In" (PDF).
  15. ^ Report, Science World (2013-12-09). "New Space Surveillance Telescope Set to Locate Space Debris From Australia". Science World Report (in American English). Retrieved 2018-01-27.
  16. ^ a b Pike, John (2010). "Space Surveillance Telescope" (Basic overview). Retrieved 2010-05-20.
  17. ^ a b Major Travis Blake, Ph.D., USAF, Program Manager (2010). "Space Surveillance Telescope (SST)" (Public Domain see Notes section). DARPA. Retrieved 2010-05-20.{{cite web}}: CS1 maint: multiple names: authors list (link)
  18. ^ "SST Australia: Signed, Sealed and Ready for Delivery" (Press release). DARPA. Archived from the original on 10 August 2014. Retrieved 18 August 2014.
  19. ^ "Residuals". Minor Planet Center. International Astronomical Uniion. Retrieved 22 October 2018.


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External links

  • Asteroid Detection with the Space Surveillance Telescope