The Launch/Early Orbit, Anomaly Resolution, and Disposal Operations (LADO) system experts from Braxton Technologies were called in to contact the satellite and regain control, and subsequently turn the wayward IIF satellite back over to the AEP control segment.
IIF-1/SVN62 Arrives on Station
During the week of August 2, the Architecture Evolution Plan (AEP) software installed at the master control station at 50th Space Wing Space Operations Centers (SOC) temporarily lost contact with or command and control (C2) of the IIF satellite undergoing testing and initialization, during a Delta V maneuver. The Launch/Early Orbit, Anomaly Resolution, and Disposal Operations (LADO) system experts from Braxton Technologies were called in to contact the satellite and regain control, and subsequently turn the wayward IIF satellite back over to the AEP control segment.
The satellite has since — or perhaps had previously — successfully reached its orbit station.
Don Jewell, GPS World Defense PNT newsletter editor, describes the event in his monthly column, which will appear on Wednesday, August 11. As Jewell says, “Similar events have happened to the IIR and IIA satellites as well — it is not a problem with the satellite, but the control segment, and fortunately LADO has been there each time to save the day.”
At the same time, Braxton was disposing of a defunct GPS satellite. “The more I hear about Braxton and LADO, the more I think of them as a baseball manager thinks of a relief pitcher,” writes Jewell. “To quote Dan Quisenberry, ‘A [baseball] manager uses a relief pitcher like a six shooter. He fires until it’s empty then takes the gun and throws it at the villain.’ In this case the analogy works, except that Braxton never seems to run out of bullets.”
The LADO system is a modern distributed system capable of meeting the requirements of a complex multi-family satellite constellation. The GPS LADO system is deployed in both the primary 50th Space Wing Space Operations Centers (SOC) and the Backup SOC at Schriever Air Force Base, Colorado.
The AEP control segment, which became operational in September 2007, constituted a multi-year cooperative effort to achieve a seamless navigation service transition to GPS users.
On August 10, the GPS Wing announced that the first GPS IIF satellite (SVN-62) arrived on-station August 1. According to the press release, “This indicates the satellite is in its designated orbital position and ready for its final phase of on-orbit checkout and testing, to be completed before September. Then the satellite will be cleared to serve navigation and timing users as part of the operational GPS constellation.
“Our next-generation GPS IIF satellites will provide improved accuracy through advanced atomic clocks, a longer design life than legacy GPS satellites, and a new operational L5 civil signal (third civil signal) that benefits civil aviation and other safety-of-life applications. It will also continue to deploy the modernized capabilities that began with the eight modernized GPS IIR satellites, including a more robust military signal. GPS IIF satellites will provide improved signals that will enhance the precise global positioning, navigation and timing services supporting both the warfighter and the growing civilian needs of our global economy. The GPS constellation remains the most robust and capable system in the history of space.”