, 83 Global Positioning System navigation satellites have been built: 31 are launched and operational, 3 in reserve or testing, 42 are retired, 2 were lost during launch, and 1 prototype was never launched. 4 Block III satellites have completed construction and have been declared "Available For Launch" (AFL). The next launch is GPS III SV07, originally scheduled for June 2024, currently NET January 2025. The constellation requires a minimum of 24 operational satellites, and allows for up to 32; typically, 31 are operational at any one time. A GPS receiver needs four satellites to work out its position in three dimensions. SVNs are "space vehicle numbers" which are serial numbers assigned to each GPS satellite. PRNs are the "pseudo-random noise" sequences, or Gold codes, that each satellite transmits to differentiate itself from other satellites in the active constellation. After being launched, GPS satellites enter a period of testing before their signals are set to "Healthy". During normal operations, certain signals may be set to "Unhealthy" to accommodate updates or testing. After decommissioning, most GPS satellites become on-orbit spares and may be recommissioned if needed. Permanently retired satellites are sent to a higher, less congested disposal orbit where their fuel is vented, batteries are intentionally depleted and communication is switched off.

Satellites

Satellites by launch date

Satellites by block

Orbital slots (by SVN)

Refer to GPS Constellation Status for the most up-to-date information. Numbers in parentheses refer to non-operational satellites. Once launched, GPS satellites do not change their plane assignment but slot assignments are somewhat arbitrary and are subject to change.

PRN status by satellite block

, 31 of 32 PRNs are in use; PRN 01 is unassigned. Two additional satellites are designated as on-orbit spares. Legend:

PRN to SVN history

This section is for the purpose of making it possible to determine the PRN associated with a SVN at a particular epoch. For example, SVN 049 had been assigned PRNs 01, 24, 27, and 30 at different times of its lifespan, whereas PRN 01 had been assigned to SVNs 032, 037, 049, 035, and 063 at different epochs. This information can be found in the IGS ANTEX file, which uses the convention "GNN" and "GNNN" for PRNs and SVNs, respectively. For example, SVN 049 is described as: BLOCK IIR-M G01 G049 2009-014A TYPE / SERIAL NO 2009 3 24 0 0 0.0000000 VALID FROM 2011 5 6 23 59 59.9999999 VALID UNTIL BLOCK IIR-M G24 G049 2009-014A TYPE / SERIAL NO 2012 2 2 0 0 0.0000000 VALID FROM 2012 3 14 23 59 59.9999999 VALID UNTIL BLOCK IIR-M G24 G049 2009-014A TYPE / SERIAL NO 2012 8 9 0 0 0.0000000 VALID FROM 2012 8 22 23 59 59.9999999 VALID UNTIL BLOCK IIR-M G27 G049 2009-014A TYPE / SERIAL NO 2012 10 18 0 0 0.0000000 VALID FROM 2013 5 9 23 59 59.9999999 VALID UNTIL BLOCK IIR-M G30 G049 2009-014A TYPE / SERIAL NO 2013 5 10 0 0 0.0000000 VALID FROM whereas for PRN 01 the following excerpt is relevant: BLOCK IIA G01 G032 1992-079A TYPE / SERIAL NO 1992 11 22 0 0 0.0000000 VALID FROM 2008 10 16 23 59 59.9999999 VALID UNTIL BLOCK IIA G01 G037 1993-032A TYPE / SERIAL NO 2008 10 23 0 0 0.0000000 VALID FROM 2009 1 6 23 59 59.9999999 VALID UNTIL BLOCK IIR-M G01 G049 2009-014A TYPE / SERIAL NO 2009 3 24 0 0 0.0000000 VALID FROM 2011 5 6 23 59 59.9999999 VALID UNTIL BLOCK IIA G01 G035 1993-054A TYPE / SERIAL NO 2011 6 2 0 0 0.0000000 VALID FROM 2011 7 12 23 59 59.9999999 VALID UNTIL BLOCK IIF G01 G063 2011-036A TYPE / SERIAL NO 2011 7 16 0 0 0.0000000 VALID FROM A table extracted out of the ANTEX file is made available by the Bernese GNSS Software.

Planned launches

Block III

Block IIIF