Citizen Explorer Update Katie Dunn Scott Miller 7/12/02 University of Colorado Space Grant

Original CX-I Problems Communication System-Critical Decoder locking up Insufficient Testing Had not used flight software to control hardware on satellite No day in the life Mission Operations testing Hardware (Peak Power Trackers with solar panels)

Solutions Using Terminal Node Controller (TNC) instead of modem Critical Decoder redesigned and rebuilt, de-scoping packetizing function (TNC now performs this function)

Solutions (cont.) Testing Minor Power Distribution and Control Unit (PDCU) improvements Peak Power Tracker (PPT) and solar panel testing Flight software nearing completion with new capabilities Updating scheduling software, almost ready for Mission Operations testing with flight hardware

Current Status Flight version of the Critical Decoder being tested with TNC in preparation for full End to End Data System test occurring by the end of the summer Phase two of PPT testing completed end of July Begin Mission Operations testing with completed flight hardware by the end of the summer

Spacecraft Completion Timeline Flight hardware done-end of summer First possible ship date-October 2002 (with on-site access to spacecraft for software uploads and functional testing) Software and full Mission Operations testing completed-December 2002 *if launch vehicle is not a Delta II, new payload adapter assembly will need to be built