Three Reasons the UCS Satellite Database is Different from Other Satellite Catalogs

April 2, 2015
Laura Grego
Senior Scientist

The purpose of the UCS Satellite Database is to provide information about the on-orbit capabilities of different actors and to provide a research tool for specialists and non-specialists alike, using open-source information about operational satellites.

We try very hard to keep the list accurate and useful, so we appreciate communication from the space community and our users suggesting improvements and pointing out errors.

While some “corrections” are truly errors, many of them arise from differences in definition of terms or misunderstanding about the Database’s purpose. For example, our aim is not to provide information on all orbiting objects (many of which are debris) or to assist in collision avoidance, nor to provide a catalogue of all objects that have ever been launched.

This post is meant to provide some clarity about the differences between the UCS Satellite Database and other indexes of satellites.

The first line in our User’s Guide states that “The UCS Satellite Database is a listing of active satellites currently in orbit around the Earth.” Simple, but it helps to unpack it.

“Actively operating” satellites

The key term is “active,” by which we mean providing the user some active capability. This usually means the satellite is able to communicate and to maneuver itself on-orbit (though we make some exceptions). Ability to maneuver is not sufficient to make a satellite active under our definition, since we are interested in capability; for example, some satellites in graveyard orbits may yet be able to maneuver, but are not providing services.


Celestis capsules (above and below), which encapsulate symbolic portions of human remains to be launched into earth orbit. The UCS Satellite Database does not include passive systems like this. (Source:

In our definition, active satellites must be able to communicate: we do not include passive satellites, such as calibration spheres for laser ranging or orbiting canisters carrying human remains. We also do not count cargo modules that attach to the International Space Station (ISS) as independent satellites, because they are also not independently-orbiting spacecraft, nor do we list ISS crew and cargo transports.  The only thing we list for the ISS is the original unit, Zarya.

The active status of a satellite can be a matter of interpretation. For example, the Stars/Kukai tethered satellite was in our database as a scientific satellite, and removed from active status once its science mission concluded. It continues communications as an amateur radio satellite and thus will be returned to the database as an active satellite.

Explorers_Integration1Also, because access to valuable geosynchronous orbit communication slots is only assured by a user’s continuous occupancy of the slot with an active satellite, satellite operators have an incentive to claim that satellites continue to be operational even when they no longer provide useful capacity, and may not even be able to maintain their orbits. Whether or not a GEO satellite under these circumstances is considered “active” is a judgment about which analysts may disagree.

Additionally, operators of classified or commercial satellites may have little incentive to officially disclose “inoperational” status, and we generally try to have multiple sources of information to cross-check, so there can be some delay in taking satellites out of the database.

“Earth-orbiting satellites”

We only include satellites that orbit the earth. We do not include craft that orbit the sun, the moon, other planets, stay at the Lagrangian points, etc.

Quarterly Updates

We produce the database on a quarterly rather than continuous basis, so by construct it will have a few differences from databases that update continuously. We chose this update period to balance providing up-to-date information with the amount of work it takes to research and cross-check our data.

Occasionally, and in particular with small “cubesats” that can be launched in relatively large numbers, we do not include satellites launched in the quarterly period until the next update because it is difficult to get accurate information for them in a timely manner.

Some examples

For example, Dr. T.S. Kelso publishes a set of differences between the UCS Satellite Database and his SATCAT catalogue.  Below is an accounting of these differences, a few of which are corrections (which we are grateful for) while most of the discrepancies are due to the above types of differences. Because they are differences in approach, most of these discrepancies are likely to continue to appear.

It may be instructive to go through these once to explain:

At the end of this listing is a list of satellites launched after January 31, after the cutoff date of our most recent Database update.

Under “Satellites incorrectly shown as inoperational,” Dr. Kelso lists 78 satellites.  Of those:

  • 18 (highlighted in red in the list below) are calibration spheres. We don’t list passive satellites used for ranging, etc.
  • 23 (highlighted in orange) are not in Earth orbit. They’re out orbiting the sun, the moon, different planets, Lagrangian points, looking for asteroids, doing deep space science, etc., etc. We only list satellites in Earth orbit.
  • 7 (highlighted in purple) are associated with the ISS.
  • 2 (highlighted in green) are Celestis units –orbiting containers carrying human remains (for those people who wished to be buried in space). They can’t be communicated with or controlled. They would more accurately be listed as debris.
  • 3 satellites, Eutelsat 9A, Yaogan 25 and Spainsat are listed here as “satellites incorrectly shown as inoperational” but are in the database, have never been removed as nonoperational.
  • 3 satellites are being listed here as non-operational by Dr. Kelso which we had considered operational. We agree with his corrections, thanks. HAMSAT (VO-52), AUBIESAT-1, VELOX-PII
  • 6 satellites were not added to the database this time around. In one case we missed it and failed to add it and in the other five cases they are cubesats we didn’t have enough information for. They will be added to the next database. DUCHIFAT-1, TRITON-1, SJ-11-08, GRIFEX, EXOCUBE, KRYSAOR
  • 6 satellites we continue to believe are best categorized as inoperational. Have noted the source information that led to their removal. SIRIUS 3, ZHONGXING-20, FORMOSAT-3, HAIYANG-1B, NTS (CANX-6), IMS-1
  • 8 satellites will be returned to the database on the basis of corrected information. OPTUS B3, IRIDIUM 46, ASTRA 1D, CHINASAT 5A/Apstar 9A, ORBCOMM FM21, GLOBALSTAR M028, CUTE-1.7+APD II (CO-65), CHINASAT 11. Thank you for the information.
  • 1 satellite is being returned to the database as an amateur radio satellite. It was removed because its primary mission was completed and mission write up did not include that it would continue as an amateur radio package. STARS (KUKAI)
  • 1 satellite is listed here as having an incorrect NORAD number. We have corrected this. Thank you. SWARM C


So here is Dr. Kelso’s list of “Satellites incorrectly shown as inoperational,” color coded as noted above or with an explanation:

NORAD Number = 00900, COSPAR Number = 1964-063C, Satellite Name = CALSPHERE 1 [Calibration]

NORAD Number = 00902, COSPAR Number = 1964-063E, Satellite Name = CALSPHERE 2 [Calibration]

NORAD Number = 01361, COSPAR Number = 1965-034C, Satellite Name = LCS 1 [Calibration]

NORAD Number = 01512, COSPAR Number = 1965-065E, Satellite Name = TEMPSAT 1 [Calibration]

NORAD Number = 01520, COSPAR Number = 1965-065H, Satellite Name = CALSPHERE 4A [Calibration]

NORAD Number = 02826, COSPAR Number = 1967-053A, Satellite Name = OPS 5712 (P/L 160) [Calibration]

NORAD Number = 02872, COSPAR Number = 1967-053F, Satellite Name = SURCAL 159 [Calibration]

NORAD Number = 02874, COSPAR Number = 1967-053H, Satellite Name = OPS 5712 (P/L 153) [Calibration]

NORAD Number = 02909, COSPAR Number = 1967-053J, Satellite Name = SURCAL 150B [Calibration]

NORAD Number = 05398, COSPAR Number = 1971-067E, Satellite Name = RIGIDSPHERE 2 (LCS 4) [Calibration]

NORAD Number = 08820, COSPAR Number = 1976-039A, Satellite Name = LAGEOS 1 [Calibration]

NORAD Number = 16908, COSPAR Number = 1986-061A, Satellite Name = AJISAI (EGS) [Calibration]

NORAD Number = 22195, COSPAR Number = 1992-070B, Satellite Name = LAGEOS 2 [Calibration]

NORAD Number = 22824, COSPAR Number = 1993-061B, Satellite Name = STELLA [Calibration]

NORAD Number = 23227, COSPAR Number = 1994-055A, Satellite Name = OPTUS B3 [Confirmed by Optus]

This satellite carries no programming and is highly inclined. It is apparently being used as a slot-holder by Optus. But since Optus wants to carry it as active, it will be returned to the database.

NORAD Number = 23331, COSPAR Number = 1994-070A, Satellite Name = ASTRA 1D [Confirmed by SES]

Removed based on: 

However, a further post to this website corrects this. Will be returned to database.

NORAD Number = 23333, COSPAR Number = 1994-071A, Satellite Name = WIND []

NORAD Number = 23726, COSPAR Number = 1995-065A, Satellite Name = SOHO []

NORAD Number = 24905, COSPAR Number = 1997-043C, Satellite Name = IRIDIUM 46 [Confirmed by Iridium]

Thank you.

NORAD Number = 24912, COSPAR Number = 1997-045A, Satellite Name = ACE []

NORAD Number = 25160, COSPAR Number = 1998-007D, Satellite Name = CELESTIS-02 & TAURUS R/B [Memorial]

NORAD Number = 25354, COSPAR Number = 1998-033A, Satellite Name = CHINASAT 5A (ZX 5A) [Active stationkeeping at 142.0 E]

This satellite was erroneously reported as retired when in fact its name was changed to Apstar 9A and it was moved to 142E. Will be returned to database.

NORAD Number = 25475, COSPAR Number = 1998-053A, Satellite Name = ORBCOMM FM21 [Confirmed by Orbcomm]

Thank you.

NORAD Number = 25492, COSPAR Number = 1998-056B, Satellite Name = SIRIUS 3 [Active stationkeeping at 51.2 E]

This satellite is not listed as active on the SES website. It carries no programming.

NORAD Number = 25575, COSPAR Number = 1998-069F, Satellite Name = ISS (UNITY) [Active part of ISS]

NORAD Number = 25875, COSPAR Number = 1999-041D, Satellite Name = GLOBALSTAR M028 [Verified active via analytical review of constellation orbits]

Information confirmed through several sources – the satellite will be returned to the database.

NORAD Number = 26034, COSPAR Number = 1999-070C, Satellite Name = CELESTIS-03 & TAURUS R/B [Memorial]

NORAD Number = 26400, COSPAR Number = 2000-037A, Satellite Name = ISS (ZVEZDA) [Active part of ISS]

NORAD Number = 26700, COSPAR Number = 2001-006B, Satellite Name = ISS (DESTINY) [Active part of ISS]

NORAD Number = 27816, COSPAR Number = 2003-022A, Satellite Name = MARS EXPRESS [Orbiting Mars:]

NORAD Number = 27871, COSPAR Number = 2003-038A, Satellite Name = SPITZER (SIRTF) []

NORAD Number = 28082, COSPAR Number = 2003-052A, Satellite Name = ZHONGXING-20 [Active stationkeeping at 103.2 E]

Removed on the basis of:

NORAD Number = 28169, COSPAR Number = 2004-006A, Satellite Name = ROSETTA [Orbiting Comet 67P/Churyumov-Gerasimenko:]

NORAD Number = 28391, COSPAR Number = 2004-030A, Satellite Name = MESSENGER [Orbiting Mercury:]

NORAD Number = 28650, COSPAR Number = 2005-017B, Satellite Name = HAMSAT (VO-52) [No longer transmitting:]

Thank you.

NORAD Number = 28788, COSPAR Number = 2005-029A, Satellite Name = MRO []

NORAD Number = 28945, COSPAR Number = 2006-007A, Satellite Name = SPAINSAT [Active stationkeeping at 30.0 W]

This satellite is in the database as an operational satellite – it has never been removed as non-operational.

NORAD Number = 28946, COSPAR Number = 2006-007B, Satellite Name = EUTELSAT 9A [Confirmed by Eutelsat]

This satellite is in the database as an operational satellite – it has never been removed as non-operational.

NORAD Number = 29049, COSPAR Number = 2006-011C, Satellite Name = FORMOSAT-3 FM5 [Confirmed by CDAAC-UCAR]

Removed based on: – This satellite has been dead since 2010.

NORAD Number = 29510, COSPAR Number = 2006-047A, Satellite Name = STEREO A []

NORAD Number = 29511, COSPAR Number = 2006-047B, Satellite Name = STEREO B []

NORAD Number = 30581, COSPAR Number = 2007-004B, Satellite Name = ARTEMIS P1 (THEMIS B) [Orbiting Moon:]

NORAD Number = 30582, COSPAR Number = 2007-004C, Satellite Name = ARTEMIS P2 (THEMIS C) [Orbiting Moon:]

NORAD Number = 31113, COSPAR Number = 2007-010A, Satellite Name = HAIYANG-1B []

Removed on the basis of:

NORAD Number = 32784, COSPAR Number = 2008-021B, Satellite Name = NTS (CANX-6) []

This satellite is listed as retired on the company’s website:

NORAD Number = 32785, COSPAR Number = 2008-021C, Satellite Name = CUTE-1.7+APD II (CO-65) []

This satellite was shown as non-operational on one online database. However, it will be returned to the database on the basis of provided information

NORAD Number = 32786, COSPAR Number = 2008-021D, Satellite Name = IMS-1 []

Removed on the basis of:   End of life listed as 12/28/13

NORAD Number = 33498, COSPAR Number = 2009-002G, Satellite Name = STARS (KUKAI) []

This had been in our database as a science mission (tether experiment) which came to a mission end. We will return it to the database as an amateur radio satellite.

NORAD Number = 35315, COSPAR Number = 2009-031A, Satellite Name = LRO [Orbiting Moon:]

NORAD Number = 36086, COSPAR Number = 2009-060A, Satellite Name = POISK [Docked to ISS]

NORAD Number = 36576, COSPAR Number = 2010-020D, Satellite Name = AKATSUKI (PLANET-C) []

NORAD Number = 36577, COSPAR Number = 2010-020E, Satellite Name = IKAROS []

NORAD Number = 37773, COSPAR Number = 2011-040A, Satellite Name = JUNO []

NORAD Number = 37854, COSPAR Number = 2011-061E, Satellite Name = AUBIESAT-1 (AO-71) []

Not operational:   Thank you

NORAD Number = 38077, COSPAR Number = 2012-006A, Satellite Name = LARES [Calibration]

NORAD Number = 39157, COSPAR Number = 2013-020A, Satellite Name = CHINASAT 11 (ZX 11) [Active stationkeeping at 98.0 E]

Thank you.

NORAD Number = 39268, COSPAR Number = 2013-055D, Satellite Name = POPACS 1 [Calibration]

NORAD Number = 39269, COSPAR Number = 2013-055E, Satellite Name = POPACS 2 [Calibration]

NORAD Number = 39270, COSPAR Number = 2013-055F, Satellite Name = POPACS 3 [Calibration]

NORAD Number = 39370, COSPAR Number = 2013-060A, Satellite Name = MARS ORBITER MISSION [Orbiting Mars:]

NORAD Number = 39378, COSPAR Number = 2013-063A, Satellite Name = MAVEN [Orbiting Mars:]

NORAD Number = 39427, COSPAR Number = 2013-066M, Satellite Name = TRITON-1 []

This was one of the cubesats on the large Dnepr launch. Added to database.

NORAD Number = 39438, COSPAR Number = 2013-066Y, Satellite Name = VELOX-PII [INACTIVE]

Nonfunctioning. See      Thank you

NORAD Number = 39441, COSPAR Number = 2013-066AB, Satellite Name = NEE-02 KRYSAOR [Confirmed with EXA]

This was one of the cubesats on the large Dnepr launch. Added to database.

NORAD Number = 39453, COSPAR Number = 2013-067C, Satellite Name = SWARM C [Wrong NORAD Catalog Number]

Thank you.

NORAD Number = 39479, COSPAR Number = 2013-074A, Satellite Name = GAIA []

NORAD Number = 40021, COSPAR Number = 2014-033M, Satellite Name = DUCHIFAT-1 []

NORAD Number = 40246, COSPAR Number = 2014-057A, Satellite Name = SOYUZ-TMA 14M [Docked to ISS]

NORAD Number = 40286, COSPAR Number = 2014-066A, Satellite Name = SJ-11-08 [Maneuvered 2015 Jan 7]

Added to database – missed for this last update.

NORAD Number = 40292, COSPAR Number = 2014-067A, Satellite Name = PROGRESS-M 25M [Docked to ISS]

NORAD Number = 40312, COSPAR Number = 2014-074A, Satellite Name = SOYUZ-TMA 15M [Docked to ISS]

NORAD Number = 40319, COSPAR Number = 2014-076A, Satellite Name = HAYABUSA 2 []

NORAD Number = 40320, COSPAR Number = 2014-076B, Satellite Name = SHIN EN 2 [Launched with HAYABUSA 2]

NORAD Number = 40321, COSPAR Number = 2014-076C, Satellite Name = DESPATCH (ARTSAT 2) [Launched with HAYABUSA 2]

NORAD Number = 40322, COSPAR Number = 2014-076D, Satellite Name = PROCYON [Launched with HAYABUSA 2]

NORAD Number = 40340, COSPAR Number = 2014-080C, Satellite Name = YAOGAN 25C [Maintaining active stationkeeping relative to 25A and B]

Is already listed in database and has never been removed as non-operational.

NORAD Number = 40379, COSPAR Number = 2015-003D, Satellite Name = GRIFEX []

Launched 1/31/15. Inadequate information at time of release – will add to next database

NORAD Number = 40380, COSPAR Number = 2015-003E, Satellite Name = EXOCUBE []

Launched 1/31/15. Inadequate information at time of release – will add to next database


The following objects were launched/deployed after the end of the period covered by the last Database update, and so will be included in the next Database update.

NORAD Number = 40381, COSPAR Number = 2015-004A, Satellite Name = IGS 9A [Launched 2015-02-01]

NORAD Number = 40384, COSPAR Number = 2015-005A, Satellite Name = INMARSAT 5-F2 [Confirmed by Inmarsat]

NORAD Number = 40389, COSPAR Number = 1998-067FM, Satellite Name = AESP 14 [Deployed from ISS 2015-02-05]

NORAD Number = 40390, COSPAR Number = 2015-007A, Satellite Name = DSCOVR [Launched 2015-02-11]

NORAD Number = 40392, COSPAR Number = 2015-008A, Satellite Name = PROGRESS-M 26M [Docked to ISS]

NORAD Number = 40420, COSPAR Number = 2015-009A, Satellite Name = COSMOS 2503 [Launched 2015-02-27]

NORAD Number = 40422, COSPAR Number = 1998-067FN, Satellite Name = FLOCK 1B-27 [Confirmed by Planet Labs]

NORAD Number = 40423, COSPAR Number = 1998-067FP, Satellite Name = FLOCK 1B-28 [Confirmed by Planet Labs]

NORAD Number = 40424, COSPAR Number = 2015-010A, Satellite Name = ABS-3A [Currently in early orbit operations]

NORAD Number = 40425, COSPAR Number = 2015-010B, Satellite Name = EUTELSAT 115 WEST B [Currently in early orbit operations]

NORAD Number = 40427, COSPAR Number = 1998-067FQ, Satellite Name = FLOCK 1B-21 [Confirmed by Planet Labs]

NORAD Number = 40428, COSPAR Number = 1998-067FR, Satellite Name = FLOCK 1B-22 [Confirmed by Planet Labs]

NORAD Number = 40429, COSPAR Number = 1998-067FS, Satellite Name = FLOCK 1B-10 [Confirmed by Planet Labs]

NORAD Number = 40430, COSPAR Number = 1998-067FT, Satellite Name = FLOCK 1B-9 [Confirmed by Planet Labs]

NORAD Number = 40451, COSPAR Number = 1998-067FU, Satellite Name = FLOCK 1D-1 [Confirmed by Planet Labs]

NORAD Number = 40452, COSPAR Number = 1998-067FV, Satellite Name = FLOCK 1D-2 [Confirmed by Planet Labs]

NORAD Number = 40453, COSPAR Number = 1998-067FW, Satellite Name = FLOCK 1B-5 [Confirmed by Planet Labs]

NORAD Number = 40454, COSPAR Number = 1998-067FX, Satellite Name = FLOCK 1B-6 [Confirmed by Planet Labs]

NORAD Number = 40455, COSPAR Number = 1998-067FY, Satellite Name = TECHEDSAT 4 [Just deployed from ISS]

NORAD Number = 40456, COSPAR Number = 1998-067FZ, Satellite Name = GEARRS-1 [Just deployed from ISS]

NORAD Number = 40457, COSPAR Number = 1998-067GA, Satellite Name = MICROMAS [Just deployed from ISS]

NORAD Number = 40458, COSPAR Number = 1998-067GB, Satellite Name = LAMBDASAT [Just deployed from ISS]

NORAD Number = 40459, COSPAR Number = 1998-067GC, Satellite Name = FLOCK 1B-11 [Confirmed by Planet Labs]

NORAD Number = 40460, COSPAR Number = 1998-067GD, Satellite Name = FLOCK 1B-12 [Confirmed by Planet Labs]