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ILRS Mission Priorities as of November 25, 2024

The ILRS has ordered its tracking priority list according to satellite orbital parameters and special project needs.Tracking priorities have been ordered as follows:

  • Priorities decrease with:
    • increasing orbital altitude; and
    • increasing orbital inclination (at a given altitude).
  • Priority of some satellites may then be increased to intensify support for:
    • active missions (such as altimetry);
    • special campaigns (such as IGEX 98); or
    • post-launch intensive tracking phases; and
  • Some slight reordering may be done to give higher priority to missions with increased importance to the analysis community.

Stations may adjust priorities to accommodate local conditions such as system capabilities, weather, and special program interests.

The ILRS priority list includes several high priority GNSS satellites. All of the remaining GNSS satellites, included on the Current or Past/Other satellites lists, can be tracked by the stations on an as time available basis; selection of targets should be determined by the stations for data yield, but stations are asked to try to diversify among all three constellations because we need some data on all three.

Satellite sponsors request for tandem mission satellites be tracked on alternate passes.

Related Links:

Current Priority List


Priority Mission ILRS
Name		 COSPAR
ID		 SIC Sponsor Altitude
(km)		 Inclination
(degrees)		 Comments
1 GRACE-FO-1/2 gracefo1
gracefo2		 1804701
1804702		 0123
0124		 NASA JPL and the German Research Centre for Geosciences (GFZ) 500 89 1-month campaign
2 ICESat-2 icesat2 1807001 6873 NASA 496 92 Restricted tracking; authorization required
3 CryoSat-2 cryosat2 1001301 8006 ESA 450-720 92  
4 PAZ paz 1802001 2501 HISDESAT 514 97.44  
5 TanDEM-X tandemx 1003001 6202 Infoterra/ DLR/GFZ/CSR 514 98 Tandem with TerraSAR-X
6 TerraSAR-X terrasarx 0702601 6201 Infoterra/ DLR/GFZ/CSR 514 97.44 Tandem with TanDEM-X
7 ALOS-4 alos4 2412301 1560 JAXA 628 97.9 Restricted tracking; authorization required
8 Sentinel-3B sentinel3b 1803901 8011 ESA/EUMETSAT 814.5 98.65

Restricted tracking; authorization required
9 Sentinel-3A sentinel3a 1601101 8010 ESA/EUMETSAT 814.5 98.65

Restricted tracking; authorization required
10 SWOT swot 2217301 4381 NASA/CNES 857 then 890 77.6  
11 Swarm-A/C swarma
swarmc		 1306702
1306703		 8007
8009		 ESA 460
530		 88.35
88.95		  
12 Swarm-B swarmb 1306701 8008 ESA 460 88.35  
13 SARAL saral 1300901 3201 CNES and ISRO 814 98.55  
14 HY-2D hy2d 2104301 2211 China 971 66  
15 HY-2C hy2c 2006601 2209 China 957 66  
16 HY-2B hy2b 1808101 2208 China 971 98.55  
17 Sentinel-6A/Jason-CSA sentinel6a 2008601 4380 NASA, ESA, EUMETSAT, NOAA, CNES 1339.4-1355.9 66.042  
18 Jason-3 jason3 1600201 4379 NASA, CNES, Eumetsat, NOAA 1,336 66.0  
19 Geo-IK-2 geoik2 1603401 5561 JSC ISS 943.5 - 973.5 99.47  
20 LARES-2 lares2 2208001 5988 ASI 5,899 70.16  
21 Larets larets 0304206 5557 IPIE 691 98.204  
22 Starlette starlette 7501001 1134 CNES 815-1,100 49.8  
23 Stella stella 9306102 0643 CNES 815 98.6  
24 LARES lares 1200601 5987 ASI 1,450 69.5  
25 LAGEOS-2 lageos2 9207002 5986 ASI/NASA 5,625 52.6  
26 LAGEOS-1 lageos1 7603901 1155 NASA 5,850 109.8  
27 Etalon-1 etalon1 8900103 0525 Russia 19,100 65.3  
28 Etalon-2 etalon2 8903903 4146 Russia 19,100 65.2  
29 Ajisai ajisai 8606101 1500 JAXA 1,485 50  
30 IRNSS-1J irnss1j 2307601 3310 ISRO 35,790 5  
31 GLONASS-141 glonass141 1908801 9141 Russia 19,140 65  
32 Galileo-102 galileo102 1106002 7102 ESA 23,220 56  
33 BeiDou-3M2 beidou3m2 1706902 2014 China Satellite Navigation Engineering Center 21,500 55  
34 IRNSS-1I irnss1i 1803501 3309 ISRO 35,786 29  
35 GLONASS-143 glonass143 2007501 9143 Russia 19,140 65  
36 Galileo-201 galileo201 1405001 7201 ESA 23,220 56  
37 Galileo-202 galileo202 1405002 7202 ESA 23,220 56  
38 BeiDou-3M3 beidou3m3 1801802 2015 China Satellite Navigation Engineering Center 21,500 55  
39 IRNSS-1C irnss1c 1406101 3303 ISRO 42,293 5  
40 GLONASS-140 glonass140 1903001 9140 Russia 19,140 65  
41 Galileo-209 galileo209 1507901 7209 ESA 23,220 56  
42 BeiDou-3M9 beidou3m9 1802901 2019 China Satellite Navigation Engineering Center 21,500 55  
43 IRNSS-1F irnss1f 1601501 3306 ISRO 35,786 29  
44 GLONASS-133 glonass133 1403201 9133 Russia 19,140 65  
45 Galileo-211 galileo211 1603001 7211 ESA 23,220 56  
46 BeiDou-3M10 beidou3m10 1802902 2020 China Satellite Navigation Engineering Center 21,500 55  
47 QZS-3 qzs3 1704801 1583 Cabinet Office, Government of Japan 36,000 0  
48 QZS-2 qzs2 1702801 1582 Cabinet Office, Government of Japan 32,000-40,000 km 45  
49 QZS-4 qzs4 1706201 1584 Cabinet Office, Government of Japan 32,000-40,000 km 45  
50 QZS-1R qzs1r 2109601 1585 Cabinet Office, Government of Japan 32,000-40,000 45  
51 Beacon-C beaconc 6503201 0317 NASA 950-1300 41  

Lunar Tracking Priorities

Priority Retroreflector Array ILRS
Name		 COSPAR
ID		 SIC Sponsor Altitude(km)
1 Apollo15 apollo15 0000103 N/A NASA 356,400
2 Apollo11 apollo11 0000100 N/A NASA 356,400
3 Apollo14 apollo14 0000102 N/A NASA 356,400
4 Luna21 luna21 0000101 N/A Russian Federation 356,400
5 Luna17 luna17 0000104 N/A Russian Federation 356,400