If you aren’t nervous for NASA’s InSight Mars probe, you probably should be.
Getting a rocket ride to the red planet is the easy part.
It’s touching down on Mars that aerospace engineers consider to be one of the greatest challenges in the solar system; in fact, about a third of missions successfully launched to the red planet don’t survive a landing.
“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,” Rob Manning, the chief engineer at NASA’s Jet Propulsion Laboratory, said in a video.
The 789-lb lander will officially begin its descent to Mars at 7:40 pm UTC (2:40 pm EST) on Monday and touch down by 7:54 pm UTC. After that, NASA hopes to use InSight to decode the internal structure of Mars, among other mysteries.
Here’s a minute-by-minute look at the biggest moments of InSight’s landing sequence — any of which could doom the robot.
7:40 pm UTC: The InSight lander, tucked inside an entry capsule, separates from the spacecraft that carried the mission to Mars.
7:41 pm UTC: The entry capsule turns to orient itself for atmospheric entry at just the right angle — about 12 degrees relative to the surface.
7:47 pm UTC: The capsule begins to plow through the first layers of the Martian atmosphere at about 12,300 mph.
7:49 pm UTC: The spacecraft’s protective heat shield reaches its maximum temperature of about 1,500 degrees Celsius. This is hot enough to melt steel.
15 seconds later: InSight slows down at its most rapid pace. The intense heating may cause a temporary radio-communications blackout.
7:51 pm UTC: InSight unfurls its supersonic parachute.
15 seconds later: Six explosive charges blow off the spacecraft’s heat shield.
10 seconds later: InSight’s three legs pop out after pyrotechnic charges explode.
7:52 pm UTC: A landing radar turns on to constantly measure InSight’s distance to the ground.
7:53 pm UTC: The first radar signals are received and processed, helping InSight tweak its approach to Mars.
20 seconds later: InSight detaches from its back shell and parachute, then begins to free-falling toward the ground.
Half a second later: The lander’s retrorockets (or descent engines) fire up.
2.5 seconds later: The falling robot uses its retrorockets to make a slight turn and orient for landing.
22 seconds later: The probe slows down to 5 mph.
7:54 pm UTC: Touchdown! InSight safely reaches the surface of Mars — NASA’s first spacecraft to land on the red planet in six years.
8:01 pm UTC: The first “I’m alive and well” signal beeps from InSight’s radio system reach Earth.
8:04 pm UTC (though possibly many hours later): InSight takes its first photo on the surface of Mars.
8:35 pm UTC: NASA’s Mars Odyssey orbiter confirms that InSight’s solar arrays have deployed, ensuring the two-Earth-year-long surface mission is ready to begin.
You can watch NASA’s live landing coverage below starting around 7 pm UTC on Monday.
This article was originally published by Business Insider.
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