No. 40 - First In-flight test of Near Sun Hibernation Mode
25 April 2005 09:46Report for period 8 to 22 April 2005
The main activity in the reporting period was the successful first in-flight test of the Near Sun Hibernation Mode (NSHM), during which the spacecraft spent five days in this special low activity mode, with attitude controlled via Star Tracker and thrusters only (gyroscopes and reaction wheels are inactive).
The NSHM test started on 11 April and ended on 15 April, with a transition back into the normal GSEP attitude control mode. During the five days of test daily monitoring of the spacecraft performance confirmed the attitude control worked as expected. This test validated the NSHM approach that will be applied in the next few weeks for a full scale commissioning of the mode.
On 19 April a pass was dedicated to a MIDAS health check, following the commanding problems that occurred during the Passive Checkout (see report #39). The result of the activity was the confirmation that MIDAS is fully functional. Taking advantage of this activity, new versions of the MIDAS switch ON and OFF OBCPs (On-Board Control Procedures), modified according to a request by the PI Team, were uploaded and verified.
No other payload operations were carried out, with the exception of SREM, which is active continuously for radiation monitoring.
A total of 10 New Norcia passes of a fixed duration of 7 hours commanding were taken at three passes per week. In one case, on 21 April, the pass duration was reduced to less than 3 hours to cover an unplanned support request by SMART-1.