ANSR-2, July 28, 2001 This was the first flight of the payload computer and real operation of the camera control computer.  We experienced near nominal performance.  The following are the problems encountered during the mission and solutions that will be implemented on future flights.

Bundle of wires between packages requires time to setup and configure before launch. Wires and connectors easily broken during decent, i.e. cut down mechanism suffered numerous failures.

Solution - Utilize Bluetooth modules for inner package communications. Bluetooth is a frequency hopping 2.4 GHz standard built for short haul, reliable communications.

The handheld Kenwood DJ-7 radio/TNC was unable to receive package data from payload computer.

Solution - Payload computer software fix to AX.25 packet data. Need additional testing to verify interoperability of various radio/TNC combinations.

Commands sent to payload computer sometimes not processed.

Solution - Software update to support connected mode TNC operation. Connected mode guarantees delivery of packet data. AFSK modulation requires a high SNR (25dB) for operation which is not always available in a moving payload package.

Time display on ATV overlay board stopped. The NMEA sentence contains a flag that indicates if the GPS data is valid. If the GPS looses lock, the flag is cleared and the data is ignored.

Solution - Software update to hold the last valid GPS position and set the data valid flag true all the time.

GPS lost lock during decent. During the decent, the internal temperature of the payload computer dipped causing the lithium battery pack voltage to sag. This sag caused a change in the power converter duty cycle and additional switching noise. The additional electrical noise caused the GPS receiver to loose lock.

ANSR-2 Flight Data

Shown below is a temperature vs. time chart from the ANSR-2 flight.

 ANSR-2 flight data.