PASADENA, CALIFORNIA-In the lab on Earth, the marching has already begun.
On November 27, the day after the successful landing of the NASA InSight landing gear on Mars, after the television teams left, technicians here at the Jet Propulsion Laboratory (JPL) were already working, imitating Mars for the full-size landing gear model they call ForeSight. Scientists do not yet know exactly where Mars Insight is. But the first few images sent back to Earth established its immediate environment, and that the landing gear was slightly tilted by 4 °. So yesterday, NASA engineers played on the sand, moving the fake Mars rocks. They raised ForeSight on their shoulders, pulling out small blocks under the nose of the landing pad to get his list just right.
Looking up from the gallery above, ForeSight was Matt Golombek, a JPL geologist who will lead the placement of two InSight instruments, a thermal probe and a seismometer. From several photographs that have been returned so far, he says that much has been learned about his whereabouts, which closely resembles the Martian landscapes previously investigated by the Spirit Scout.
For example, InSight landed in a so-called void, a crater that was filled with soil and leveled. In the pictures taken from the elbow of the seated robotic arm of the landing gear, the crater can be stolen. As soon as the team determines the diameter of the crater – it can be meters, maybe tens of meters – the researchers can deduce their depth and the amount of sand blown into it. In any case, it bodes well for a device with a heat probe, called HP3, which should easily penetrate the material. “This will be good news for HP3, as you might hope,” he says.
Landing in the void was successful for another reason. InSight did not quite hit the bullish eye of its target landing zone and found itself in an area that was, in general, more rocky than desired. But emptiness is largely devoid of rocks. One, about 20 centimeters in diameter, sits close to the legs of the landing module, while the three smaller ones lie further – but no one presents a threat to the placement of tools. The hollow is flat and has no sand dunes, and small pebbles indicate a surface sufficiently dense to support the weight of the tools. “We will have no problems,” says Golombek.
The biggest mystery for the collector is now finding out right where she is. The Mars orbiter, set to image the center of the landing zone on Thursday, will miss the landing module, because it missed the center a little. The tool on the InSight, called the inertial measuring unit, fixed the location within a 5-kilometer circle. The InSight entry, descent and landing command will refine this estimate to a kilometer or less. “But they haven’t done that yet because they were so happy that they landed safely, that we don’t know what they did last night,” Golombek says with a smile. "And they have not yet appeared today."
There is another technique that can help: the third InSight primary experiment, called the rotation and internal structure experiment (RISE). The primary goal of two sensitive RISE listening antennas is to detect wobblers in the Martian core. But the InSight team can also use them to match the latitude and longitude of the landing module using the radio signals of the passing orbitals. This gave geologists a place within about 100 meters or so.
Now there is a friendly competition. Golombek and his peers hope to beat the satellites in order to fix the location of InSight. They should have until December 6, when the orbiter is likely to capture it. Right now, they are stretching scant images, trying to compare their emptiness with existing high-resolution maps. Their work will be much easier next week, when the camera on the elbow of the robotic arm will be enlarged to photograph the terrain of the landing gear in detail. At the moment, the hand is laid – on Tuesday it was about simple steps, such as firing small charges that kept a hand on the deck. But later this week, after the caps of the camera come off and the hand is free, detailed reconnaissance will begin.