NASA Perseverance landing today: When & how to watch the Mars rover

It's the big day the plucky Mars 2020 rover Perseverance has been waiting for, with NASA preparing a nail-biting descent to the red planet today. If all goes to plan, it'll be a successful end to a very long journey: Mars is currently 127 million miles away from Earth, with Perseverance blasting off to begin its trip on July 30, 2020.

Perseverance isn't the first Mars rover, of course, but it's definitely NASA's most complex and adept. Its payload of seven scientific instruments and 19 cameras will give scientists unprecedented views both of the Martian surface, and underneath, as the rover attempts to help unlock the secrets of the planet's origins. However arguably the most exciting part of the mission is designed to detached.

Perseverance will also take a helicopter, named Ingenuity, down to the surface. It's designed to come away from the rover and then take to the skies, beaming down imagery of the Jezero crater in which NASA intends to land, and helping plan for future missions. If successful, it'll be the first example of powered flight on another planet that humankind has achieved.

Though Perseverance is designed to run for some time on Mars, its legacy will be even longer-lasting. One of the mission goals is to collect samples from the surface and underneath it, package them up into special containers, and then leave them for a future Mars mission to collect. They'll then be returned to Earth for analysis, though that's not expected to take place until some time in the 2030s.

Before that, of course, the rover has to make it down in one piece. If all goes to plan, that'll begin at around 3:48pm EST (12:48pm PST) today, February 18, 2021. According to the schedule, touchdown should take place at around 3:55pm EST.

It's just a few minutes, but a fairly harrowing trip. Entry, Descent, and Landing begins when the spacecraft arrives at the Martian atmosphere, at which point it's traveling at close to 12,500 mph. For 90 seconds or so it decelerates in the atmospheric friction, with a vast parachute deploying when it's around 6-8 miles above the planet's surface. At that point it's expected to be traveling at around 940 mph.

When the speed drops to around 360 mph, at an altitude of around 4-7 miles, the heat shield separates. The spacecraft then opens the next minute or so scanning the ground to figure out a final safe landing spot, at which point the back shell separates and powered descent begins, the rover transported down on a separate craft which then lowers it to the surface with a "Sky Crane" before flying away.

That's a whole lot to get right, and Perseverance will be figuring it out on its own. The entire descent process is preprogrammed, since it would take a signal over 11 minutes to reach Mars from Earth.

You'll be able to watch the whole thing in the below video livestream: