December 16, 2024 saw the very low-key and somethat hush-hush launch of GPS III SV-07 from Space Launch Complex 40 at Cape Canaveral Space Force Station aboard a SpaceX FALCON 9 Block 5 booster. The original contract for this launch was allocated to a United Launch Alliance (ULA) VULCAN rocket, but due to uncertainties regarding VULCAN's readiness, the mission was shifted to SpaceX. As a result, the GPS III SV-10 mission, originally allocated to SpaceX, will now be launched by ULA's VULCAN booster, planned for later in 2025.
The SV-07 space vehicle had been sitting in a Lockheed Martine warehouse in Colorado after having been declared as status "launch ready" in August of 2021. The satellite had to be refitted to integrate with a FALCON 9 booster after having been originally configured for the VULCAN rocket.
Adding to the problems, the satellite was transported to Florida via truck instead of the usual military transport aircraft, which were being tied up in hurricane HELENE recovery operations. Ground transportation required special equipment such as a climate-controlled enclosure and shock absorbers. A military caravan accompanied the transport truck along the multi-day drive.
The GPS III SV-07 is the seventh of ten GPS III series modernized GPS satellites which have increased signal power and use M-code to help overcome jamming. The GPS III satellites also provide the new L1C and L2C civilian signals, and transmit the L5 high-accuracy signal intended for aviation users.
In a very rapid transition, on January 22, 2025 GPS III SV-07 was declared "operational." It is orbiting in slot D2 and transmitting PRN 01, replacing the GPS IIF-2 satellite launched in July 2011 which had been in that orbit and using that PRN and was retired in August 2023.
There are three more GPS-III series satellites ready for launch. These will be followed by the GPS IIIF series, which will add further improvements. GPS IIIF will also carry a new 406-MHz search-and-rescue transponder, expanding the global medium-earth-orbit (MEO) segment for SARSAT.
The first launch of a GPS III satellite occurred in December 2018. See
GPS III Scheduled for Launch December 2018
https://continuouswave.com/forum/viewto ... =12&t=4066
The initial plan estimates called for the GPS III series of ten satellites to be in service by 2025, with GPS IIIF to follow. Current estimates anticipate the first GPS IIIF to be delayed until 2027.
For more about MEO 406-MHz SARSAT, see
SARSAT MEO 406-MHz System on GALILEO FOC Satellites
https://continuouswave.com/forum/viewto ... =12&t=2951
and
SARSAT MEO 406-MHz Systems on GPS Satellites
https://continuouswave.com/forum/viewto ... =12&t=2952