Heat treatment straightens out MARSIS boom
Flight controllers on the Mars Express mission successfully deployed the troublesome first boom of the MARSIS experiment. All it needed was a little bit of heat.
When the first antenna began to open on 4 May, all but one of the 13 segments locked into position correctly. One section, probably the 10th, had unfolded, but was not locked in place. It was almost as though the boom had a crick in its neck after being folded up for so long en-route to, and in orbit around, Mars.
The mission engineers reasoned that since the cold of space can affect the Kevlar and fibre glass of the boom, they needed to heat the area in the hopes that it would expand the cold part, forcing the segment to lock out properly. So they swung the spacecraft around so that the cold side of the boom faced the distant sun. After an hour, the data suggested that the plan had worked, and the final piece had locked into place.
Mission controllers had postponed deployment of the second and third booms, until the problem with the first could be rectified. Mission scientists are still working on a thorough analysis of what exactly happened with boom one, but now that everything is in place, the rest of the unfurling should be resumed within the next few weeks.
The MARSIS experiment, full name Mars Express Sub-Surface Sounding Radar Altimeter experiment, is designed to map the Martian sub-surface structure to a depth of a few kilometres. It is one of seven scientific experiments on board the craft. ®