After nearly six years of development and 80 million miles cruising through space, NASA's Mars InSight finally touched down on the red planet on Nov. 26. Unlike other robotic science labs on Mars, Insight — which stands for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport — will stay put, using its various instruments to probe the planet's internal secrets.
"We know a lot about the surface of Mars, we know a lot about its atmosphere and even about its ionosphere," said Bruce Banerdt, the mission's principal investigator, in a video. "But we don’t know very much about what goes on a mile below the surface, much less 2,000 miles below the surface."
Below are a few highlights for a mission that, if successful, will provide us with the first internal vital signs of an alien world.
InSight's '7 minutes of terror'
On Nov. 26 shortly before 3 p.m. EST, InSight began its 80-mile-high journey through Mars' atmosphere and to its surface — a trial referred to by NASA engineers as "7 minutes of terror." During this critical moment in its mission, any number of missteps can doom the spacecraft.
"Although we've done it before, landing on Mars is hard, and this mission is no different," Rob Manning, chief engineer at NASA's Jet Propulsion Laboratory in Pasadena, California, said in a video. "It takes thousands of steps to go from the top of the atmosphere to the surface, and each one of them has to work perfectly to be a successful mission."
While NASA itself has a strong track record of landing spacecraft on Mars, the success rate across all missions to the red planet is still only 40 percent.
After hitting the Martian atmosphere at precisely the right angle of 12 degrees, Insight's heat shield protected the spacecraft from temperatures over 1,800 degrees Fahrenheit as it slowed from 13,000 mph to 1,000 mph. A supersonic parachute then deployed, the heat shield jettisoned, and then — at an altitude of about a mile — its descent engines fired.
"The last thing that has to happen is that, on the moment of contact, the engines have to shut down immediately," Manning said. "If they don't, the vehicle will tip over."
With all of this taking place over the course of less than seven minutes, it's no wonder that everyone at NASA was holding their breath during the descent phase.
It's based off the Mars Phoenix Lander
InSight builds upon the successful engineering behind the Phoenix Mars Lander. That mission, the first to successfully land in a Martian polar region, lasted from May 2008 to November 2008.
While Phoenix was designed to seek out water and environments suitable for microbial life on Mars, InSight will probe Mars' internal secrets. By touching down near the equator, it's also hoped that the lander's two 7-foot-wide solar panels will benefit from longer days and higher angles of sunlight. To that end, NASA expects InSight to last at least one Martian year (two Earth years) before possibly succumbing to the region's harsh environment.
"Hopefully it will last a lot longer than that," Tom Hoffman, InSight project manager from NASA's Jet Propulsion Laboratory, told the AFP.
Home will be 'the biggest parking lot on Mars'
While NASA generally chooses regions with intriguing surface geology to study, for the first time they're much more interested in what they can't see. InSight descended on an 81-mile-long, 17-mile-wide region on Mars called Elysium Planitia. According to InSight principal investigator Bruce Banerdt, the site is perfectly unremarkable.
"If Elysium Planitia were a salad, it would consist of romaine lettuce and kale – no dressing," he said in a statement. "If it were an ice cream, it would be vanilla."
Elysium Planitia was chosen from 22 finalists, ultimately beating out the competition thanks to its low elevation, relative flatness, low wind and relative lack of surface rocks. As Banerdt adds, the real excitement will come from studying what's happening beneath the lander.
"While I'm looking forward to those first images from the surface, I am even more eager to see the first data sets revealing what is happening deep below our landing pads," he said. "The beauty of this mission is happening below the surface. Elysium Planitia is perfect."
Taking the pulse of Mars
Almost immediately after InSight touches down and unfurls its solar arrays, an 8-foot robotic arm will begin unpacking a variety of scientific instruments to analyze Mars' vital signs. These include a seismometer (the first placed on another planet) for tracking Marsquakes and a self-hammering "mole" that will burrow up to 16 feet into the ground and record Mars' internal temperature.
"Ninety-nine-point-nine percent of this planet has never been observed before," Banerdt told NPR. "And we're going to go and observe it with our seismometer and with our heat flow probe for the very first time."
In addition to sensors to record wind and temperature at Elysium Planitia, as well as two cameras for monitoring both the site and the lander's instruments, InSight will also use its X-band radio to provide precise measurements of Mars' rotation and build on previous estimates regarding its core. Scientists are hopeful this data will further help our understanding of how terrestrial planets form.
"How we get from a ball of featureless rock into a planet that may or may not support life is a key question," Banerdt told CBS News. "And these processes that do this all happen in the first few tens of millions of years. We'd like to be able to understand what happened, and the clues to that are in the structure of the planet that gets set up in these early years."
2.4 million names on InSight
Accompanying InSight to Mars will be no less than 2.4 million names. Over the course of two campaigns, NASA asked the public to submit either their own names, or names of loved ones, to be etched onto two microchips embedded on the surface of InSight. A total of 2,429,807 names ended up being gathered, with each etched using an electron beam to cut letters only 1/1000 the width of a human hair.
"Mars continues to excite space enthusiasts of all ages," Banerdt said. "This opportunity lets them become a part of the spacecraft that will study the inside of the Red Planet."
Editor's note: This article has been updated since it was originally published in November 2018.