GPS Gaps Closing Up; West Coast Launches Aired

Anthony Russo, director of the U.S. National Space-Based PNT Coordination Office, told the Munich Satellite Navigation Summit last month that, regarding the May 7, 2009, U.S. General Accountability Office report that forecast gaps in constellation availability, “The GAO will revise its report somewhat. They were using a model that was a little too cautious, one used by the [GPS] Wing. But satellites on orbit have been performing past estimated life. Further, we can turn off secondary payloads to conserve energy onboard satellites [and thus extend life] if needed.”

GPS satellites have proven themselves very hardy in space, outlasting their predicted lifetimes. Relying on those longer lives, the Air Force has saved money by replenishing upon need. But the GAO report apparently used more conservative lifetimes for the mathematical models of constellation availability. When those models were projected against the real-world timelines for IIF and Block III, some gaps appeared. Now the GAO and the Wing will re-undertake this exercise, factoring instead the longer lifetimes that the satellites have proved capable of.

In a hearing before the U.S. Senate Subcommittee on Strategic Forces, Committee on Armed Services on March 10, the following exchange occurred.

Senator BEN NELSON.  “Ms. Chaplain, last year, the GAO issued a report that resulted in some significant and very negative press coverage about the health and reliability of the GPS system. Could you update us on the GAO’s assessment, now, of the GPS system?”

Ms. CHAPLAIN (Director, Acquisition and Sourcing Management,
from the Government Accountability Office (GAO)).
“Yes. We’re currently conducting a review—a follow- on review. And the two programs we looked at, on the satellite side last year, were the IIF program and the IIIA program. And the IIF program has made some progress, and it’s getting ready for a launch fairly soon.

“The IIIA program is on—it’s meeting its schedule currently. We still have concerns about the compressed nature of the schedule, and all the very difficult activities ahead for GPS IIIA, but it is not encountering any severe problems at this point.

“When we look at the health of the Constellation, our findings are pretty similar to last year’s. One thing we weren’t discussing in last year’s report, that should probably brought out more when we talk about it this year, is some of the options the Air Force has available to it to manage GPS if they do have—experience some dips in the Constellation availability. There are options that they have to get through those periods.

“Our concern is, you just—you don’t want to find yourself in a state where you’re looking at those kind of options; you want to make sure you do everything you can to keep the program healthy, resourced, and on track.”

A recent story in Spaceflight Now attributes to Gary Payton, the undersecretary of the Air Force for space, a statement that the Air Force currently has under review an option  is to move some high-inclination flights, including future GPS satellite launches from Cape Canaveral to Vandenberg Air Force Base in California.

“We would like to be able to get to the point where we can project six months or a year down the road that we’re going to have a surge of launches all ganged too close together, that we may pull a GPS launch over to Vandenberg,” the story quotes Payton as saying. “The same rocket and orbitology allows you to launch out of Vandenberg.”