UNITED STATES NAVAL OBSERVATORY (USNO) BLOCK II SATELLITE INFORMATION GPS OPERATIONAL SATELLITES (BLOCK II/IIA/IIR/IIR-M/IIF) =================================================== The operational GPS satellites are designated BLOCK II, BLOCK IIA, BLOCK IIR, BLOCK IIR-M, and BLOCK 11F. The BLOCK II satellites, space vehicle numbers (SVN) 13 through 21, are the first full scale operational satellites developed by Rockwell International. Block II satellites were designed to provide 14 days of operation without contact from the Control Segment (CS). The Block IIs were launched from February 1989 through October 1990. The BLOCK IIA satellites, SVNs 22 through 40, are the second series of operational satellites, also developed by Rockwell International. Block IIA satellites were designed to provide 180 days of operation without contact from the CS. During the 180 day autonomy, degraded accuracy will be evident in the navigation message. The Block IIAs were launched November 1990 through November 1997. The design life of the Block II/IIA satellite is 7.3 years; each contain four atomic clocks: two Cesium (Cs) and two Rubidium (Rb); and have the Selective Availabity (SA) and Anti-Spoof (A-S) capabilities. The Block II/IIA satellites were launched from Cape Canaveral Air Force Station, Florida, aboard the Delta II medium launch vehicle (MLV). The BLOCK IIR satellites, SVNs 41 through 61, are the operational replenishment satellites developed by Lockheed Martin and will carry the GPS well into the next century. Block IIR satellites are designed to provide at least 14 days of operation without contact from the CS and up to 180 days of operation when operating in the autonomous navigation (AUTONAV) mode. Full accuracy will be maintained using a technique of ranging and communication between the Block IIR satellites. The cross- link ranging will be used to estimate and update the parameters in the navigation message of each Block IIR satellite without contact from the CS. The design life of the Block IIR satellite is 7.8 years; each contains three Rb atomic clocks and have the SA and A-S capabilities. Launching of the Block IIRs began in January 1997. The BLOCK IIR-M satellites transmit a second civil signal L2C on the L2 frequency and the military M signal on the L1 and L2 frequencies. SVN 49 also transmits on the L5 frequency. The BLOCK IIF satellites transmit all signals including on the L5 freqency, intended for safety-of-life applications. Launching of the Block IIFs began in May 2010. Projected Future: 11 more BLOCK IIF satellites and 30 BLOCK III. LAUNCHES ======== GPS IIF-1 (SVN62/PRN25) was launched on 28 MAY 2010 at 0300 UT from Cape Canaveral, Florida. CURRENT BLOCK II/IIA/IIR/IIR-M SATELLITES ========================================= LAUNCH LAUNCH FREQ US SPACE ORDER PRN SVN DATE STD PLANE COMMAND ** ----------------------------------------------------------------- *II-1 14 14 FEB 1989 19802 *II-2 13 10 JUN 1989 20061 *II-3 16 18 AUG 1989 20185 *II-4 19 21 OCT 1989 20302 *II-5 17 11 DEC 1989 20361 *II-6 18 24 JAN 1990 20452 *II-7 20 26 MAR 1990 20533 *II-8 21 02 AUG 1990 20724 *II-9 15 01 OCT 1990 20830 IIA-10 32 23 26 NOV 1990 Rb E5 20959 *IIA-11 24 04 JUL 1991 Cs 21552 *IIA-12 25 23 FEB 1992 Rb 21890 *IIA-13 28 10 APR 1992 21930 IIA-14 26 26 07 JUL 1992 Rb F5 22014 IIA-15 27 27 09 SEP 1992 Cs A6 22108 *IIA-16 32 22 NOV 1992 22231 *IIA-17 29 18 DEC 1992 22275 *IIA-18 22 03 FEB 1993 22446 *IIA-19 31 30 MAR 1993 22581 *IIA-20 37 13 MAY 1993 22657 IIA-21 09 39 26 JUN 1993 Cs A1 22700 IIA-22 30 35 30 AUG 1993 Rb B5 22779 IIA-23 04 34 26 OCT 1993 Rb D4 22877 IIA-24 06 36 10 MAR 1994 Rb C6 23027 IIA-25 03 33 28 MAR 1996 Cs C2 23833 IIA-26 10 40 16 JUL 1996 Cs E6 23953 IIA-27 30 30 12 SEP 1996 Cs B2 24320 IIA-28 08 38 06 NOV 1997 Cs A3 25030 ***IIR-1 42 17 JAN 1997 IIR-2 13 43 23 JUL 1997 Rb F3 24876 IIR-3 11 46 07 OCT 1999 Rb D5 25933 IIR-4 20 51 11 MAY 2000 Rb E1 26360 IIR-5 28 44 16 JUL 2000 Rb B3 26407 IIR-6 14 41 10 NOV 2000 Rb F1 26605 IIR-7 18 54 30 JAN 2001 Rb E4 26690 IIR-8 16 56 29 JAN 2003 Rb B1 27663 IIR-9 21 45 31 MAR 2003 Rb D3 27704 IIR-10 22 47 21 DEC 2003 Rb E2 28129 IIR-11 19 59 20 MAR 2004 Rb C3 28190 IIR-12 23 60 23 JUN 2004 Rb F4 28361 IIR-13 02 61 06 NOV 2004 Rb D1 28474 IIR-14M 17 53 26 SEP 2005 Rb C4 28874 IIR-15M 31 52 25 SEP 2006 Rb A2 29486 IIR-16M 12 58 17 NOV 2006 Rb B4 29601 IIR-17M 15 55 17 OCT 2007 Rb F2 32260 IIR-18M 29 57 20 DEC 2007 Rb C1 32384 IIR-19M 07 48 15 MAR 2008 Rb A4 32711 *IIR-20M 49 24 MAR 2009 Rb 34661 IIR-21M 05 50 17 AUG 2009 Rb E3 35752 IIF-1 25 62 28 MAY 2010 Rb B2 36585 IIF-2 01 63 16 JUL 2011 Rb D2 36585 * Satellite is no longer in service. ** US SPACE COMMAND, previously known as the NORAD object number; also referred to as the NASA Catalog number. Assigned at successful launch. Catalog numbers retrieved from SPACEWARN Bulletins: http://nssdc.gsfc.nasa.gov/spacewarn/ *** Unsuccessful launch. HISTORY OF BLOCK II/IIA/IIR/IIR-M/IIF SATELLITES AND STATUS ======================================================= SVN PRN 13 02 Launched 10 JUN 1989; usable 10 AUG 1989; decommissioned 12 MAY 2004 Set unusable 22 Feb 2004 at 1037 UT (NANU 2004025) Decommissioned from active service 12 MAY 2004 at 1701 UT. 14 14 Launched 14 FEB 1989; usable 15 APR 1989; decommissioned 14 APR 2000 Unusable 29 AUG 1992 2030 UT to 01 SEP 1992 1425 UT due to the failure of its operational frequency standard and change to its second Cs frequency standard. Unusable 26 JAN 2000 0130 UT to 03 FEB 2000 1816 UT due to change in operational frequency standard from Cs to Rb. Set unusable 26 MAR 2000 at 2348 UT. Decommissioned from active service 14 APR 2000 at 1347 UT. 15 15 Launched 01 OCT 1990; usable 15 OCT 1990; decommissioned 15 MAR 2007 Unusable 10 NOV 1992 1604 UT to 13 NOV 1992 1910 UT due to change in operational Cs frequency standards. Set as a test vehicle on 17 NOV 2006. Decommissioned from active service 14 MAR 2007. 16 16 Launched 18 AUG 1989; usable 14 OCT 1989; decommissioned 13 OCT 2000 Unusable 07 JAN 1991 1200 UT to 09 JAN 1991 1639 UT due to change in operational frequency standard from Rb to Cs. Unusable 06 FEB 1996 0556 UT to 21 FEB 1996 1648 UT due to change in operational Cs frequency standards. Unusable 04 MAR 2000 0955 UT to 07 APR 2000 2112 UT due to change in operational frequency standard from Cs to Rb. Decommissioned from active service 13 Oct 2000 at 0045 UT. 17 17 Launched 11 DEC 1989; usable 06 JAN 1990; decommissioned 23 FEB 2005 Unusable 06 APR 2001 1848 UT to 16 APR 2001 2253 UT due to change in operational frequency standard from Cs to Rb. Unusable 07 OCT 2002 0110 UT to 15 OCT 2002 1626 UT due to change in operational frequency standard from Rb to Cs. Unusable 26 JUN 2003 1942 UT to 22 JUL 2003 1600 UT due to change in operational frequency standard from Cs to Rb. Decommissioned from active service 23 Feb 2005 at 2200 UT. 18 18 Launched 24 JAN 1990; usable 14 FEB 1990; decommissioned 18 AUG 2000 Unusable 07 MAY 1996 0406 UT to 09 MAY 1996 1737 UT due to change in operational Cs frequency standards. Decommissioned from active service 18 Aug 2000 at 0742 UT. 19 19 Launched 21 OCT 1989; usable 23 NOV 1989; decommissioned 11 SEP 2001 Unusable 16 OCT 1994 0545 UT to 19 OCT 1994 1354 UT due to change in operational frequency standard from Cs to Rb. The course acquisition (C/A) code deficiency problem on PRN19 was corrected effective 04 JAN 1994 at 0000 UT; performance no longer degraded. Unusable 30 DEC 1994 0536 UT to 04 JAN 1995 1740 UT due to change in operational Rb frequency standards. Unusable 22 SEP 1999 1715 UT to 04 OCT 1999 1727 UT due to change in operational frequency standard from Rb to Cs. Unusable beginning 16 MAR 2001 at 0126 UT and will remain unusable until further notice. Decommissioned from active service 11 SEP 2001 at 2200 UT. 20 20 Launched 26 MAR 1990; usable 18 APR 1990; decommissioned 13 DEC 1996 Unusable 06 AUG 1994 0000 UT to 17 AUG 1994 1908 UT due to change in operational frequency standard from Cs to Rb. Unusable 13 JAN 1996 0937 to 1355 UT due to change in operational frequency standard from Rb to Cs. Set unusable 21 MAY 1996 at 2242 UT and will not return to service. Boosted out of the GPS constellation 13 Dec 1996. 21 21 Launched 02 AUG 1990; usable 22 AUG 1990; decommissioned 27 JAN 2003 Unusable 07 OCT 1996 1430 UT to 10 OCT 1996 2152 UT due to change in operational Cs frequency standards. Set unusable 25 SEP 2002 at 1830 UT and decommissioned from active service 27 JAN 03 at 2200 UT. 22 22 Launched 03 FEB 1993; usable 04 APR 1993; decommissioned 06 AUG 2003 Unusable 07 OCT 1998 1102 UT to 14 OCT 1998 2229 UT due to change in operational frequency standard from Cs to Rb. Unusable 28 JUL 2001 2358 UT to 11 AUG 2001 0413 UT due to change in operational Rb frequency standards. Unusable 05 NOV 2002 1756 UT to 18 NOV 2002 1403 UT due to change in operational frequency standard from Rb to Cs. Set unusable 03 DEC 2002 at 1402 UT and decomissioned from active service 06 AUG 2003 at 2200 UT. 23 23 Launched 26 NOV 1990; usable 10 DEC 1990; decommissioned 13 FEB 2004 Unusable 04 JAN 1991 1600 UT to 06 JAN 1991 2049 UT due to change in operational Cs frequency standards. Unusable 13 NOV 2003 0121 UT to 25 NOV 2003 2104 UT due to change in operational frequency standard from Cs to Rb. Set unusable 05 FEB 2004 at 2030 UT and decommissioned from active service 13 FEB 2004 at 2200 UT. 23 32 Launched 26 NOV 1990; Usable 26 FEB 2008; Operates on Rb std An initial assessment period for SVN23 utilizing PRN32 was accomplished 01 DEC to 06 DEC 2006; SVN23 is no longer transmitting L-band. During this assessment period SVN23 was broadcasting L-band and set unhealthy. SVN23 was not included in the operational constellation almanac. (NANU 2006155) On 02 APR 2007, SVN23 will resume transmitting L-band utilizing PRN32. At L-band activation, SVN23/PRN32 will be unusable until further notice. Additionally, no broadcast almanancs will include SVN23/PRN32. (NANU 2007051) On 27 JUN 2007, after 2200 ZULU, GPS will transition SVN23/PRN32 into the broadcast almanacs for all satellites. Before, during, and after transition, PRN32/SVN23 will remain unusable until further notice. (NANU 2007081) Set usable 26 FEB 2008 at 1801 UT (NANU 2008024) Anyone experiencing problems with PRN32 should contact the appropriate agency listed below: CIVILIAN - NAVCEN AT COMM 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV MILITARY - GPS OPERATIONS CENTER AT DSN 560-2541 OR COMM 719-567-2451, HTTP://GPS.AFSPC.AF.MIL/GPSOC/ MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-9994 OR COMM 805-606-9994, EMAIL: JSPOC_COMBAT_OPS@VANDENBERG.AF.MIL 24 24 Launched 04 JUL 1991; usable 30 AUG 1991; Operates on Cs std Unusable 23 JAN 1994 1745 UT to 01 FEB 1994 1516 UT due to change in operational frequency standard from Cs to Rb. Unusable 01 JUL 1995 0750 UT to 07 JUL 1995 2223 UT due to change in operational Rb frequency standards. Unusable 07 SEP 2000 1742 UT to 11 SEP 2000 2020 UT due to change in operational frequency standard from Rb to Cs. Will be transitioned out of the broadcast almanac after 12 Sept 2009 at 2200 UT (NANU 2009065) Unusable 12 Sept 2009 at 2017 UT until further notice (NANU 2009066) 25 25 Launched 23 FEB 1992; usable 24 MAR 1992; Operates on Rb std Unusable 01 DEC 1993 1904 UT to 05 DEC 1993 1941 UT due to change in operational frequency standard from Rb to Cs on 02 DEC 1993. Unusable 07 JAN 1995 1938 UT to 12 JAN 1995 1821 UT due to change in operational Cs frequency standards. Unusable 22 Mar 2006 0149 UT to 28 Mar 2006 0144 UT due to change in operational frequency standard from Cs to Rb. Set unusable 20 Aug 2009 at 1514 UT and decommissioned from active service 20 Aug 2009 at 1514 UT. Will be transitioned into the broadcast almanac after 12 Sept 2009 at 2200 UT; Usable during transition (NANU 2009065) Set usable 12 Sept 2009 at 2212 UT (NANU 2009067) Set unusable 18 Dec 2009 at 1522 UT and decommissioned from active service 18 Dec 2009 at 2228 UT. (NANU 2009131) 26 26 Launched 07 JUL 1992; usable 23 JUL 1992; Operates on Rb std Unusable 10 Mar 1998 1541 UT to 16 Mar 1998 1818 UT due to change in operational frequency standard from Cs to Rb. 27 27 Launched 09 SEP 1992; usable 30 SEP 1992; Operates on Cs std Unusable 10 Jun 2002 1516 UT to 20 Jun 2002 1402 UT due to change in operational frequency standard from Cs to Rb. Unusable 14 MAY 2005 1955 UT to 31 MAY 2005 1749 UT due to change in operational frequency standard from Rb to Cs. 28 28 Launched 10 APR 1992; usable 25 APR 1992; decommissioned 15 AUG 1997 Unusable beginning 04 NOV 1996 1634 UT and will remain unusable until further notice (NANU 179-96309) Removed from broadcast almanac of all GPS satellites 15 AUG 1997. 29 29 Launched 18 DEC 1992; usable 05 JAN 1993; decomissioned 23 OCT 2007 Unusable 21 MAY 1997 1504 UT to 31 MAY 1997 0355 UT due to change in operational frequency standard from Cs to Rb. Unusable 01 MAR 2007 1445 UT to 12 MAR 2007 2124 UT due to change in operational frequency standard from Rb to Cs. 30 30 Launched 12 SEP 1996; usable 01 OCT 1996; Operates on Cs std Unusable 29 Aug 2001 2102 UT to 04 Sep 2001 2055 UT due to change in operational frequency standard from Cs to Rb. Unusable 02 JUN 2006 to 07 JUN 2006 due to change in operational frequency standard from Rb to Cs. 31 31 Launched 30 MAR 1993; usable 13 APR 1993; decommissioned 24 OCT 2005 Unusable 17 JAN 1995 1705 UT to 25 JAN 1995 2013 UT due to change in operational frequency standard from Cs to Rb on 18 JAN 1995. The MCS and P-code users experienced intermittent lock on the L2 navigation signal of PRN31 from 13 Apr 1993 2053 UT to 16 Jun 1993 0824 UT. Since corrective maintenance was performed on 16 Jun 1993, the MCS has not experienced lock problems on PRN31's L2 navigation signal. Change in operational frequency standard from Rb to Cs on 23 JUL 1997. Unusable 15 APR 2002 1431 UT to 23 APR 2002 2018 UT due to change in operational frequency standard from Cs to Rb. Unusable 28 DEC 2004 0042 UT to 04 APR 2005 0913 UT, during the outage a change in operational frequency standard from Rb to Cs. 32 01 Launched 22 NOV 1992; usable 11 DEC 1992; decommisioned 17 MAR 2008 Unusable 28 JAN 1993 2000 to 2200 UT for maintenance and changed the Pseudo Range Number (PRN) from 32 to 01. Unusable 03 MAY 1995 0604 UT to 12 MAY 1995 1528 UT due to change in operational frequency standard from Cs to Rb. Unusable 16 AUG 1996 1655 UT to 22 AUG 1996 1620 UT due to change in operational frequency standard from Rb to Cs. Set unusable 17 Mar 2008 at 1953 UT (NANU 2008030) Decommissioned from active service 17 MAR 2008 at 2200 UT. 33 03 Launched 28 MAR 1996; usable 09 APR 1996; Operates on Cs std Unusable 18 JUN 2006 to 29 JUN 2006 due to change in operational frequency standard from Cs to Rb. Unusable 27 DEC 2006 0120 UT to 08 JAN 2007 1723 UT due to change in operational frequency standard from Rb to Cs. 34 04 Launched 26 OCT 1993; usable 22 NOV 1993; Operates on Rb std Unusable 13 Sep 1998 1728 UT to 21 Sep 1998 2214 UT due to change in operational frequency standard from Cs to Rb. 35 05 Launched 30 AUG 1993; usable 28 SEP 1993; Operates on Rb std Unusable 02 Jun 2003 1518 UT to 09 Jun 2003 1417 UT due to change in operational frequency standard from Cs to Rb. Unusable 26 Sep 2003 0745 UT to 14 Oct 2003 1633 UT due to change in operational frequency standard from Rb to Cs. Unusable 08 SEP 2005 0032 UT to 16 SEP 2005 1945 UT due to change in operational frequency standard from Cs to Rb. Set unusable 26 Mar 2009 at 1320 UT and decommissioned from active service 26 Mar 2009 at 2031 UT. 36 06 Launched 10 MAR 1994; usable 28 MAR 1994; Operates on Rb std Unusable 27 Apr 1995 1447 UT to 03 May 1995 0541 UT due to change in operational frequency standard from Rb to Cs. Unusable 17 Mar 2004 1531 UT to 29 Mar 2004 1558 UT due to change in operational frequency standard from Cs to Rb. 37 07 Launched 13 MAY 1993; usable 12 JUN 1993; decommissioned 20 DEC 2007 Unusable 20 Apr 1999 0437 UT to 26 Apr 1999 1533 UT due to change in operational frequency standard from Cs to Rb. Unusable 30 MAR 1994 0730 UT to 04 APR 1994 1330 UT due to change in operational Cs frequency standards. Unusable 20 Apr 1999 0437 UT to 26 Apr 1999 1533 UT due to change in operational frequency standard from Cs to Rb. Unusable 17 Aug 2007 0748 UT to 17 Sep 2007 2122 UT due to change in operational Rb frequency standards. 37 01 Will Resume Transmition of L-Band on PRN01 on approx 23 Oct 2008. Unusable Until Further Notice (NANU 2008031) Discontinued Trasmition of L-Band on PRN01 on 06 Jan 2009. 38 08 Launched 06 NOV 1997; usable 18 DEC 1997; Operates on Cs std Unusable 05 May 2004 0906 UT to 18 May 2004 0142 UT due to change in operational frequency standard from Rb to Cs. 39 09 Launched 26 JUN 1993; usable 21 JUL 1993; Operates on Cs std Unusable 15 Oct 1993 1200 UT to 07 Dec 1993 1940 UT due to testing Unusable 31 Oct 2005 1506 UT to 15 Nov 2005 0026 UT due to change in operational frequency standard from Cs to Rb. Unusable 19 Dec 2005 1449 UT to 24 Dec 2005 0738 UT due to change in operational Cs frequency standards. 40 10 Launched 16 JUL 1996; usable 15 AUG 1996; Operates on Cs std Unusable 28 Nov 1996 2018 UT to 01 Dec 1996 2325 UT due to change in operational frequency standard from Rb to Cs. Unusable 24 Aug 2007 1751 UT to 18 Sep 2007 2028 UT due to change in operational frequency standard from Cs to Rb. Unusable 25 Mar 2008 0230 UT to 27 Mar 2008 2349 UT due to change in operational frequency standard from Rb to Cs. 41 14 Launched 10 NOV 2000; usable 10 Dec 2000; Operates on Rb std 43 13 Launched 23 JUL 1997; usable 31 Jan 1998; Operates on Rb std 44 28 Launched 16 JUL 2000; usable 17 Aug 2000; Operates on Rb std 45 21 Launched 31 MAR 2003; usable 12 Apr 2003; Operates on Rb std 46 11 Launched 07 OCT 1999; usable 03 Jan 2000; Operates on Rb std 47 22 Launched 21 DEC 2003; usable 12 Jan 2004; Operates on Rb std 48 07 Launched 15 MAR 2008; usable 24 Mar 2008; Operates on Rb std 49 01 Launched 24 MAR 2009; ; Operates on Rb std Decommissioned from active service 06 MAY 2011 50 05 Launched 17 AUG 2009; usable 27 AUG 2009; Operates on Rb std 51 20 Launched 11 MAY 2000; usable 01 Jun 2000; Operates on Rb std 52 31 Launched 25 SEP 2006; usable 12 Oct 2006; Operates on Rb std 53 17 Launched 26 SEP 2005; usable 16 Dec 2005; Operates on Rb std 54 18 Launched 30 JAN 2001; usable 15 Feb 2001; Operates on Rb std 55 15 Launched 17 OCT 2007; usable 31 Oct 2007; Operates on Rb std 56 16 Launched 29 JAN 2003; usable 19 Feb 2003; Operates on Rb std 57 29 Launched 21 DEC 2007; usable 02 Jan 2008; Operates on Rb std 58 12 Launched 17 NOV 2006; usable 13 Dec 2006; Operates on Rb std 59 19 Launched 20 MAR 2004; usable 05 Apr 2004; Operates on Rb std 60 23 Launched 23 JUN 2004; usable 09 Jul 2004; Operates on Rb std 61 02 Launched 06 JUN 2004; usable 22 Nov 2004; Operates on Rb std 62 25 Launched 28 MAY 2010; usable 27 AUG 2010; Operates on Rb std PERIODIC MAINTENANCE AND MANEUVERS ================================== The backup cesiums on-board each Block II/IIA satellite require periodic, approximately twice per year, pumping of the beam tube to maintain working order. This maintenance requires, on average, 18 hours of unusable time for each satellite. Once per year each satellite requires a stationkeeping maneuver, also referred to as repositioning or Delta-V, to move the satellite back to its original orbital position. The satellites have a tendency to "drift" from their assigned orbital positions, one reason being the earth's gravitational pull. These maneuvers require, on average, 12 hours of unusable time for each satellite. CURRENT GPS CONSTELLATION ========================= The current GPS constellation consists of 31 Block IIA/IIR/IIR-M satellites. The first operational, Block II, satellite was launched in February 1989. For information concerning: CURRENT STATUS see file . . . . gpstd.txt GPS SYSTEM see file . . . . gpssy.txt TIME TRANSFER see file . . . . gpstt.txt BLOCK I see file . . . . gpsb1.txt -- File gpsb2.txt last updated Wed Jan 25 17:52:06 UTC 2012