Tuesday , August 20 2019
Home / unitedstates / Mars mission got lucky: NASA lander touched down in a sand-filled crater, easing study of planet's interior | Science

Mars mission got lucky: NASA lander touched down in a sand-filled crater, easing study of planet's interior | Science

Pictures from InSight show the lander sits in a flat, sand-filled crater.

JPL-Caltech / NASA

By Paul Voosen

PASADENA, CALIFORNIA-In a laboratory on Earth, the marsforming had already begun.

On November 27th, the day after the successful landing of NASA's InSight lander on Mars, after the television crews had departed, technicians here at the Jet Propulsion Laboratory (JPL) were already at work simulating Mars for a full-size lander model. , which they call ForeSight. Scientists do not yet know exactly where in Mars InSight is. But the first few images sent back to Earth have established their immediate environment and that the lander is slightly tilted by 4 °. So yesterday, NASA engineers were playing in the sand, moving fake Mars rocks into position. They heaved ForeSight up on their shoulders while shoving small blocks underneath a lander leg to get it listing just right.

Looking ahead from Forex, Matt Golombek, a JPL geologist who will lead the placement of two InSight instruments, a heat probe and a seismometer. From the few photos returned so far, he says, much has been learned about its location, which closely resembles the martian terrain previously scouted by the Spirit rover.

For example, InSight landed in what's called a hollow, a crater that was filled with soil and leveled flat. In images taken from the elbow of the lander's stooped robotic arm, the edge of the crater is visible. Once the team determines the diameter of the crater, it could be meters, maybe tens of meters-researchers can infer its depth and the amount of sand it is blown into it. Either way, this bodes well for the heat probe instrument, called HP3, which should penetrate the material with ease. "This is about as good news for HP3 as you could possibly hope," he says.

Landing in the hollow was fortunate for another reason. InSight did not quite hit the bull's-eye of its target landing zone, and it ended up in terrain that, overall, is rockier than desired. But the hollow is mostly devoid of rocks. One, about 20 centimeters across, sits close to the lander's feet, while three smaller ones are farther away-but none poses a threat to placing the instruments. The hollow is flat and has no sand dunes, and small pebbles indicate a surface that is thick enough to support the weight of the instruments. "We have no problems whatsoever," Golombek says.

The biggest mystery for the lander team right now is figuring out exactly where it is. A Mars orbiter is set to take the center of the landing zone on Thursday, because it missed the center slightly. An instrument on InSight called the inertial measurement unit has pinned the location to within a 5-kilometer-wide circle. InSight's entry, descent, and landing team will refine that estimate to a kilometer or less. "But they have not done that yet, because they were so happy to have landed safely, that we do not know what they did last night," Golombek says with a smile. "And they have not yet shown today."

There is one more technique that could help: InSight's third primary experiment, called the Rotation and Interior Structure Experiment (RISE). The main purpose of RISE's two sensitive listening antennas is to detect wobbles in the martian core. But the InSight team can also use them to map the lander's latitude and longitude by using passing orbits radio signals. That has given geologists a place to within about 100 meters or so.

Now a friendly competition is on. Golombek and his peers hope to beat the satellites to fix InSight's location. They should have until 6 December, when an orbiter will likely capture it. Right now, they're stretching out the scant images, trying to compare their hollow to existing high-resolution maps. Their job will be much easier next week, when the camera on the robotic arm's elbow will be extended to photograph the lander's terrain in detail. For now, the arm was stowed-Tuesday was about simple steps, like firing off the small charges that secure the arm to the deck. But later this week, after the camera caps come off and the arm is released, the detailed reconnaissance will begin.

Source link