8/17/2011 – SCHREIVER AIR FORCE BASE, Colo. — Demonstrating the strength of the Global Positioning System constellation of satellites, the 2nd Space Operations Squadron is set to swap out an underperforming satellite with a handy spare this week.

During late May, 2 SOPS analysts began noticing signs that SVN-30, a GPS IIA vehicle, was no longer maintaining the gold standard of performance. Engineers in 2 SOPS, along with their civilian partners from Boeing and the Aerospace Corporation began developing a plan to recall SVN-35 back into service to replace the ailing SVN-30.

“The vehicle we’re replacing has a clock that’s malfunctioning,” said Capt. Frankie Reddick, 2 SOPS assistant director of operations and previously an analysis flight commander within the squadron. “When its clock started to show signs of going out, our engineers knew we needed to do something because it wasn’t suitable for our global users.”

SVN-35, also a Block IIA satellite, was decommissioned from active service back in 2009 to make room in the constellation for the launch and eventual deployment of the latest new GPS Block IIR vehicle.

Meanwhile, SVN-35’s timing and navigation signal kept ringing true, so when the need arose for a spare, 2 SOPS analysts knew just where to go.

“We keep on-orbit spares for exactly this purpose,” said Lt. Col. Jennifer Grant, 2 SOPS commander. “The robustness of our current constellation and the recent completion of the Expandable 24 architecture provide us with the flexibility to perform replacements like this with minimal impact to global users. Expandable 24 increases global GPS coverage by optimizing the location of GPS satellites in space. SVN-35 will replace a satellite residing in an expanded slot of the constellation.”

This event marks the second time in the more than 25-year history of the GPS program that operators will transition a decommissioned vehicle back to active status.

“We’ve started moving SVN-35 from its decommissioned location to an active slot,” Reddick said. “During the next week, we’ll test the vehicle and if it’s still performing like it was when we turned it on back during June, we’ll set it healthy to users as it is moving.”

Reddick noted that all of the extra work is being performed by engineers, analysts and operators here, who have really put some elbow grease into making the transition seamless for worldwide military and commercial application users.

Lt. Col. Dean Holthaus, 2 SOPS director of operations, said that SVN-35 has surpassed its designed lifespan by 11 years. Not bad for a spacecraft that was constructed during an era when people were still using typewriters and analog telephones.

“SVN-35 was launched in 1993, with a design life of 7.5 years,” Holthaus said. “My hat goes off to our operators, analysts, and contractor support personnel — their superior care and feeding of our constellation is the reason SVN-35 is still viable for operations 18 years after launch.”