Artist’s rendition of a GPS-IIR satellite in orbit. (Image: GPS.gov)
The U.S. Space Force has announced the decommissioning of GPS satellite SVN-47 (PRN-22), which officially took place Jan. 18. The satellite has been unusable since Dec. 2.
SVN-47 was a replacement satellite in the second generation of GPS satellites (GPS-IIR), launched Dec. 21, 2003.
The announcement was made in a Notice Advisory to NavStar Users (NANU 2022001) issued by NAVCEN, U.S. Coast Guard.
The designation PRN-22 will be used to bring SVN-41 back in to the active constellation. After 2200 Zulu on Jan. 2o, GPS will transition SVN-41 (PRN-22) into the broadcast almanac for all satellites, and SVN-41 will resume transmitting L-band signals. The almanac transition, accomplished one satellite at a time, will require approximately 24 hours to complete.
A second NANU emphasized that “Before, during, and after transition SVN-41 (PRN22) will remain unusable until further notice.”
SVN-41, the sixth of the GPS-IIR satellites, was launched on Nov. 10, 2000, and set to active service a month later on Dec. 10. It was decommissioned in July 2021.
The U.S. Coast Guard has issued a Notice Advisory to Navstar Users (NANU) detailing the changes to the constellation now that the second GPS III satellite has joined.
The U.S. Space Force Second Space Operations Squadron (2 SOPS) issued an Initial Use (USABINIT) NANU for the second of the new generation of GPS-III satellites, designated SVN-75/PRN-18.
SVN-75 was launched on Aug. 22, 2019, and — having successfully undergone rigorous operational testing on orbit — has taken its place in the active GPS constellation with the slot and plane designation of D6.
Constellation changes
Artist’s rendering of GPS IIF satellite. (Image: U.S. Air Force )
SVN-45/PRN-21 is being re-phased from D3 to D2F replacing SVN46. Upon its arrival, SVN-46/PRN-11 will then be moved to residual status in Launch, Anomaly and Disposal Operations (LADO).
SVN-60/PRN-23 was decommissioned on March 2, eight and a half years beyond its expected service life. SVN-60 was the 12th GPS-IIR to go in to orbit, and began service on July 9, 2004.
The second GPS III satellite, nicknamed Magellan, has been designated healthy and usable.
According to a Notice of Advisory to Navstar Users (NANU) issued by the U.S. Coast Guard, the satellite has been designated usable as of April 1, 1945 ZULU.
The 2nd Space Operations Squadron (2 SOPS) accepted control of the Magellan on March 27 at the Schriever Air Force Base in Colorado.
Designated Satellite Vehicle Number 75 (SVN75) in the GPS constellation, Magellan is the second GPS III satellite to be accepted into the program, and the first to be accepted during a global pandemic.
The second GPS III satellite is encapsulated before launch. (Photo: Lockheed Martin)
“We’re continuing to make major strides even while working through this pandemic, and we continue to expand our capability to further the program along,” said Lt. Col Stephen Toth, 2 SOPS commander. “This is a huge, momentous occasion for us, that we’re reaching this milestone, that our programs are being delivered, that they’re being executed and the systems are performing as expected. Ultimately, we’re all very excited that we’ve accomplished this major milestone in the program’s history, and we’re very excited for the next things to come.”
The new generation of GPS III vehicles have a 15-year design life and signals that are three times more accurate than the current generation.
“[This means users will have] better accuracy anywhere in the world, with a user’s device being able to determine their location more reliably,” said Capt. Ryan Thompson, 2nd SOPS assistant director of operations.
Additionally, the new satellites have eight times improved anti-jam capability, allowing the military warfighter to operate better in contested, degraded and operationally limited environments.
The vehicles are designed to be forward and backward compatible, which allows them to adapt to the future while remaining fully adaptable to the previous generation of vehicles.
Eight more GPS III satellites are scheduled to launch from now until 2025.
Despite any challenges that may arise, 2nd SOPS remains focused on the mission and continues to make history in space.
“As we’ve moved forward into the Space Force, we’ve taken a bigger mindset approach toward being warfighters,” Toth said. “What COVID has actually brought out of us is the full understanding of what it is to operate with a warfighter mindset. We may not be at war with an enemy per say, but we are definitely at war with the virus. My job is to ensure we continue to provide position, navigation and timing to the world. And we take that very seriously, so despite the virus, we’ll ensure that our mission continues.”
In a notice advisory to NAVSTAR Users (NANU), the U.S. Coast Guard Navigation Center announced that starting March 7, after 22:00 Zulu hours, GPS will transition satellite SVN34 (PRN18) into the broadcast almanac for all satellites.
The almanac transition, one satellite at a time, will require approximately 24 hours to complete.
Also, on approximately March 8, SVN34 will resume transmitting L-band utilizing PRN18. SVN34/PRN18 will be unusable until further notice.
Future NANUs will notify users of any changes to the above stated status.
Contact the navigation center for more information:
