When the successful landing of NASA's InSight lander was confirmed, the control room erupted in applause and cheering. What makes the spacecraft's arrival at Mars so special and what will we learn from the mission?
“Touchdown confirmed!” After this simple transmission was broadcast live over NASA TV, the control room at NASA’s Jet Propulsion laboratory erupted in applause, hugs, and scientists fist bumping. On Monday, November 26th, 2018, NASA’s Insight Lander successfully landed on Mars with the mission of exploring the planet’s interior.
A few hours after landing, scientists still didn’t know the full state of the vehicle, but the lander sent its first communications back to Earth in a so-far best case scenario that its instruments are in working order. InSight has even already posted its first photo on Twitter. So why is the successful landing of InSight so interesting and what will we learn from the mission?
1. The InSight landing was an incredible accomplishment.
We’ve landed complicated (and expensive) spacecraft on Mars several times now so the successful arrival of InSight at the red planet may seem like old hat by now but I assure you, it is a very big deal.
For starters, InSight traveled 301 million miles after being launched 205 days ago from the west coast of the United States on the Atlas V rocket. The spacecraft approached Mars at a speed of roughly 13,000 miles per hour before having to decelerate on its approach to the red planet to 1,000 miles per hour (a change in 12Gs in 2 minutes). In the process, the heat shield reached temperatures higher than 2700 degrees F, hot enough to melt steel.
The spacecraft also had to enter the Martian atmosphere at just the right angle of 12 degrees. Too much steeper and temperatures would have been too hot for the spacecraft’s survival. Too much shallower and the spacecraft would have bounced off the atmosphere and headed back out to space.
On approach all of the landing gear had to work and work together. The parachute had to deploy, little explosions blew off the heat shield, and the craft’s legs had to pop out once the spacecraft’s radar detected the ground was 1 kilometer away. Finally, retroboosters came to life to slow the lander to 5 miles per hour before it plunked down onto the surface of the planet. Twelve engines worked to keep the lander going at a constant velocity as it approached the ground in hopes that none of the equipment was too badly bruised in the final jolt at touchdown.
Of 43 missions to Mars, only 18 have made it. NASA crashed a craft into the Martian south pole in 1999, only a year after the Mars Climate Orbiter disintegrated upon entering the Martian atmosphere. The European Space Agency lost its Schiaparelli Lander in 2016 after it didn’t survive the crash to the surface. So, like I said, landing successfully on Mars is still a very big deal.
2. The InSight Mars Lander is different from the Rovers.
Why another mission to Mars? Well, unlike the Mars Exploration Rovers, Spirit and Opportunity, or the Mars Science Laboratory Rover, Curiosity, that were designed to travel the red planet to learn about different types of surface terrain, the InSight Lander is built to stay put once it lands. That’s because InSight’s main purpose will be to dig. The Curiosity Rover which landed on Mars in 2012 dug down only a few inches while InSight is prepared to explore as far down as 16 feet or about 5 meters below the surface.
The InSight team has chosen Elysium Planitia as its landing site specifically because it is flat and boring and thus a good place to explore what is beneath the surface.