What determined whether data were downlinked live or recorded on the shuttle?
All data was recorded onboard the shuttle. Appropriate communications links were available about once per day to downlink the data. This once-a-day opportunity was shared by both the X-band and C-band, and data was played back in real time if it was collected at that time, or tape-recorded data was played back. The C-band and X-band shared the link time according to mutually agreed on priorities established during mission planning. The downlinked data was used to verify the performance of the sensor.
