The premature shut-down of the Indian Space Research Organisation's Chandrayaan-1 lunar mission on 29 August also brought to a close an interesting joint effort with NASA's Lunar Reconnaissance Orbiter (LRO) where both agencies were deploying US-provided synthetic aperture radars for bi-static observations aimed at finding water ice at the moon's poles.
Chandrayaan-1 too carried US-supplied synthetic aperture radar.
|Artist's concept of LRO: NASA|
The experiment intended to make use of the proximity of both spacecraft to each other in their separate orbits around the moon to look down into a deep crater from slightly different angles so as to confirm the presence of ice at its bottom.
The tricky bistatic manoeuvre was carried out on 20 August over the Erlanger Crater near the moon's North Pole. It was timed to coincide with a moment when both spacecraft were only 20 kilometers (12.4 miles) apart. This proximity would provide enough of an angle for differences in the radar-reflection brightness to signify whether the source was rock or ice.
The attempt failed because of 'pointing' problems, media reports quote Stewart Nozette, principal investigator on the LRO's Mini-RF, as saying. Ground controllers, it appears, managed to get data back from both spacecraft, but it was unusable.
Both agencies agreed for a retry, but it was around this time that contact was lost with the Indian orbiter.