A 21-hour Canada flight was completed on December 18. The aircraft had 10% less range than Northrop Grumman had expected, probably due to the slightly higher drag of the UAVSAR configuration. This is the first time that the radar transited at altitudes above 50kft. Temperature readings of various radar components at 60kft altitude were high but within acceptable range. Six data takes were recorded but were receiving error messages which indicated active array antenna commanding fault throughout the flight. Brief post-flight testing revealed that antenna commanding fault was most likely caused by physical damage in the antenna control path, such as a broken wire. Investigation of the cause of the connection failure and corrective action will continue.
The good news is that quick fixes made to improve the Onboard Processor software robustness worked, and we were able to process radar data and save processed imagery onboard although we did not have the Ku-band satellite link for most of the flight to downlink the imagery in real time. We were able to play back the processed imagery when the Ku-band link returned an hour before landing which showed that the antenna was not transmitting during the data takes (as speculated).
Northrop Grumman would like to fund UAVSAR to repeat the Canada mission sometime this year (March or June).
Pictured is a Polarimetric color-overlay image of Owens Lake from the first engineering flight on Friday, December 13. This data take was acquired at 41 kft, comparable to G-III altitudes.