Author: GPS World Staff

News compiled with the assistance of CANSPACE listserv.

After a brief delay due to concerns over solar radiation trends, the GPS IIF-5 satellite was successfully launched at the end of the designated launch window at 01:59 UTC on February 21. The satellite, attached to the launch rocket’s upper stage, was initially placed in a highly elliptical orbit. Following a third burn of the rocket, the satellite was released into its assigned orbit at about 05:37 UTC today.

Here is a video showing highlights of the launch:

GPS IIF-5 will replace the aging spacecraft known as GPS IIA-28 in Plane A, Slot 3 of the constellation.The GPS IIA-28 satellite was launched aboard Delta 249 on November 5, 1997, as the final member of the Block IIA series. It will go into a reserve role in the network for the remainder of its useful life.

This is the first of three GPS launches planned through July to replace aging craft in the constellation. GPS IIF-5 incrementally upgrades the constellation with improved accuracy, enhanced internal atomic clocks, better anti-jam resistance, a civil signal for commercial aviation, and a longer design life, all features of the Boeing-build Block IIF series. This will be the fifth of 12 Block IIF spacecraft being built to form the backbone of the GPS fleet for the next 15 years.

According to the Air Force, the new capabilities of the IIF satellites will provide greater navigational accuracy through improvements in atomic clock technology, a more robust signal for commercial aviation and safety-of-life applications, known as the new third civil signal (L5), a second civil signal (L2C) available for the dual-frequency GPS receivers and a 12-year design life providing long-term service. These upgrades improve anti-jam capabilities for the warfighter and improve security for military and civil users around the world.

“I am pleased with the outcome of today’s launch. The new capabilities provided by the IIF satellites will improve operations, sustainment and overall GPS service for the warfighter, international, commercial and civil communities,” said Col. Bill Cooley, director of the Space and Missile Systems Center’s Global Positioning Systems Directorate.

“The modernized capabilities that are coming on board with the successful launch of GPS IIF-5 will support the worldwide GPS community for years to come. I would like to recognize the outstanding commitment and the superb dedication to mission success from the 45th and 50th Space Wings, our industry partners: Boeing and United Launch Alliance, and the GPS IIF and Delta IV program teams at the Space and Missile Systems Center,” said he said.

The GPS Block IIF satellites are built by Boeing, and are operated by the United States Air Force following their launch by United Launch Alliance, using Evolved Expendable Launch Vehicles.

• The first GPS IIF satellite was launched on May 27, 2010, and entered service on Aug. 26, 2010.
• The second satellite, which launched on July 16, 2011, entered service on Aug. 22, 2011.
• The third satellite launched on Oct. 4, 2012, and entered service 22 days later.
• The fourth IIF was launched May 15, 2013, and entered service on June 21, 2013.

Every modern GPS satellite was launched from Cape Canaveral Air Force Station.

Each GPS IIF satellite delivers:

• Greater navigational accuracy through improvements in atomic clock technology,
• A new civilian L5 signal to aid commercial aviation and search and rescue operations,
• Improved military signal and variable power for better resistance to jamming in hostile environments,
• A 12-year design life providing long-term service and reduced operating costs,
• An on-orbit, reprogrammable processor that can receive software uploads for improved system operation.

“Once again, a group of talented mission partners rose to the challenge of launching another successful mission from the Cape,” said Col. Douglas Schiess, commander, 45th Operations Group, who served as the Launch Decision Authority. “Those mission partners include the 45th Space Wing, the Space and Missile Systems Center, the 50th Space Wing, United Launch Alliance, Boeing, and our other industry partners with the Delta IV and GPS IIF launch teams.”