InSight will make similar course corrections on its way to Mars. The lander, with its spindly legs and round solar panels on either side, looks kind of like a mosquito. It will delve deeper than previous missions, which were concerned mostly with the Martian surface, like canyons, rocks, and soil, and investigate the planet’s interior, its crust, mantle, and core.
After landing, the lander’s 7-foot-long arm will extract two instruments and place them on the surface in front of it. A seismometer will track quakes, which on Mars are called, appropriately, Marsquakes. Scientists believe quakes could be produced by meteorites hitting the surface or tectonic activity beneath the surface. A “heat probe” will measure the planet’s interior temperature. Back on the spacecraft, two radio antennas will track how the interior affects the planet’s motion around the sun.
And there will be a camera, ready to capture the lander’s little workspace millions of miles away from Earth.
Scientists hope the InSight mission will help them learn more about the formation of the solar system’s rocky planets, including Earth. Of course, InSight has to survive the journey and then stick the landing before any of that happens. And sending a spacecraft to Mars is easier than gently setting it down on the surface.
Only one country, the United States, has successfully landed something on Mars (though there have been failures, and as recently as 1999). Several landers launched by the Soviet Union in the 1970s all failed, either during descent or minutes after landing. The last attempt to put a lander on Mars was in 2016 by the Europeans. The spacecraft, named Schiaparelli after a 19th-century astronomer, crashed. In images taken by Mars orbiters afterward, Schiaparelli appears as a charcoal-colored splat against the rusty-red terrain.
When the time for landing comes for InSight, Matt Golombek will get brought in. Golombek is “the landing site guy” at NASA’s Jet Propulsion Laboratory in California; he’s spent 20 years picking out and evaluating potential sites for Mars missions, including the first successful rover, Sojourner, which reached the planet in 1997. The landing site for every Mars mission is always “a smooth, flat, boring place,” Golombek said. Rocky terrain, sharp outcrops, and sloped areas could all damage or tip over spacecraft. And since InSight doesn’t have roaming powers, the team has little room for error. The landing procedures are automated, so there’s not much they can do as the spacecraft makes it descent.
“It’s sort of like launch,” Golombek said. “You’re sitting there, the rocket’s all preprogrammed, and all you can do is pray that it does its job.”
I asked him if he ever gets impatient during the months-long wait until this nail-biting moment.
“No, I think I’ve done this enough times to know that it doesn’t matter,” he said. “You’re just gonna have to wait.”