WA8LMF Mirror of WB4APR Website - 21 July 2008 REX-II

REX-II is a unique opportunity for the Naval Academy Satellite Lab to gain operational experience on an on-orbit spacecraft. REX is operated by Prof Boden via daily command schedules prepared during weekly planning sessions. Like any real program it comes complete with its LOGO and PATCH.

The Naval Academy took over control of REX-II in July of 1999 and faced the first task of the Y2K problem. Because the processor on REX-II was not Y2K compliant, its clock had been reset back from 1999 to 1995. Thus its ground station is operated on current UTC time minus 4 years. The amazing thing is that the real-time clock on REX-II is still operating within a fraction of a second of correct time and we have not touched it since 1999.

The REX-II ground station performs an overhead contact about twice a day with no anomolies, though we recently went through a hard disk failure on the original PC and fortunately, recovered the drive long enough to make several backup systems. We are currently operating on a rack-mount Pentium PC. As of January 2003, the REX-II clock is running fine as 1999. At the end of this year, we will have to again address the Y2K issue by resetting the REX-II clock back to 1995.

Bob Bruninga (webmaster)

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USNA Satellite Ground Station

Midshipmen Amateur Radio Club

WA8LMF Mirror of WB4APR Website - 21 July 2008