While the first satellite awaits its payload, Lockheed Martin has been doing as much bus testing as possible so as not to waste time.
The GPS nonflight satellite testbed (GNST) is now about three months from completing its pathfinder work for the first tranche of GPS III satellites, Jackson says. It is now in the final stages of trials in the anechoic chamber. Lockheed Martin hopes to have completed a run-through of pre-launch processing activities at Cape Canaveral in the third quarter of the year. The pathfinder will complete its task when it has been used for demonstrating stacking and pre-launch integration.
Then, the GNST will be used as a testbed for a series of upgrades that would be included in Space Vehicles 9 and beyond. Key assets included in this next set of GPS III satellites are the capability to “dual launch” the spacecraft from United Launch Alliance Atlas V rockets, an advanced search-and-rescue payload, and digital waveform generators that allow for signal upgrading after a satellite is launched, Jackson says. Work on these technologies is in the formative stages. The Air Force is considering buying as many as 12 of these satellites, but a strategy has not yet been refined.
A long-desired “spot-beam” capability that would allow for a high-power signal, impervious to current GPS jamming, has been dashed for now. This spot beam was originally eyed for a third block of satellites, and it could come back into play in a later tranche.