After black-out test last year, MOM overcomes ‘white-out’ phase

BENGALURU: The Indian Space Research Organisation’s (Isro) Mars Orbiter Mission (MOM) spacecraft experienced, what scientists call the ‘whiteout’ geometry, between May 18 and May 30 when MOM had no contact with the ground stations.
A ‘whiteout’ occurs when the Earth is between the Sun and Mars and too much solar radiation may make it impossible to communicate with the Earth.“The planets continuously in motion can align with the sun causing ‘whiteout’ or 'blackout' causing communication disruptions. In this particular geometry, the Earth came in between the Sun and Mars causing a whiteout,” Isro said.
The maximum duration of whiteout is around 14 days. MOM, built with full autonomy to take care of itself for long periods without any ground intervention, had experienced a blackout phase due to a solar eclipse on Mars around the same time last year and had successfully come out of it to regain communication with the ground station.
“The entire planning and commanding for the ‘whiteout’ was completed 10 days before the actual event. No commanding was carried out on the satellite in the ‘whiteout’ period. Payload operations were suspended,” Isro said.
The space agency added: “...Fault Detection, Isolation and Recovery were kept enabled, so as to take care of any contingency on the spacecraft. Master Recovery Sequencer was programmed, to acquire the attitude of the spacecraft and ensure communication with earth even in case of loss of attitude.”
The spacecraft came out of ‘whiteout’ geometry successfully on May 30, 2016 and has been normalised for regular operations.