NASA (ABC4) – The biggest rover ever has been sent to another planet and has a critical manufacturing experiment from Utah on board. Perseverance is pulling up to Mars, ending its approach phase.
The landing will happen on Feb 18.
What happens when you start a landing at 12,100 mph? NASA engineers call it “7 minutes of terror” There is a delay in what is happening on MARS and being able to monitor it here on Earth of 11 minutes and 22 seconds.
According to NASA, “The intense entry, descent, and landing (EDL) phase begin when the spacecraft reaches the top of the Martian atmosphere. EDL ends about seven minutes later, with the rover stationary on the Martian surface.”
Utah’s OxEon Energy is responsible for a device that will manufacture oxygen on the alien planet that will go through the descent. Their V.P. of engineering Joseph Hartvigsen says: “From what I understand, and as the MOXIE team we’re just passengers along for the ride, there are many challenges but those responsible are making statements of confidence.”
According to NASA, Perseverances landing is the most difficult because the rover is landing in the “most challenging terrain ever targeted.” The Jezero Crater is a 28-mile-wide impact basin with an intriguing ancient river delta as well as cliffs, dunes, boulder fields, and smaller impact craters.”
In a statement sent out by NASA, here’s what’s going to happen at about 1:38 p.m. Utah time when the Rover lands. Even though there is a delay, cameras will be on to document the landing.
“10 minutes before entering the Martian atmosphere – the Mars 2020 spacecraft will shed the cruise stage that helped fly Perseverance and Ingenuity to Mars. The spacecraft will manipulate its descent into Mars’ atmosphere using a technique called guided entry to reduce the size of the targeted ellipse-shaped landing area on Mars while compensating for variations in the density of the Martian atmosphere and drag on the vehicle. During guided entry, small thrusters on the back of the aeroshell will adjust the angle and direction of lift, enabling the spacecraft to control how far downrange it is flying.”
“Peak heating occurs about 75 seconds after atmospheric entry when the temperature at the external surface of the heat shield will reach about 2,370 degrees Fahrenheit (about 1,300 degrees Celsius). About three minutes later, Perseverance’s parachute is expected to deploy with the help of a new technique called Range Trigger.”
Range Trigger is astonishing technology that calculates the distance to the landing target and opens the parachute at just the right time. The spacecraft has now slowed to 940 mph.
When the parachute deploys, it will slow down the Rover through the atmosphere, 20 seconds after, the heat shield separates.
Hartvigsen adds, “The spacecraft has cameras and microphones to capture this sequence for the first time. We’ll all have a front-row seat to the 7-minutes of terror, but it will all be over before the data gets to earth.”
After the parachute sequence, just like it’s straight out of Star Wars, eight retro-rockets will fire. They’re called Mars landing engines. They will help the aircraft fly to a safe landing site and help slow the spacecraft.
NASA notes when the motors turn on; the spacecraft has slowed to 190 mph, it slows to 1.7 mph with 66 feet left to land.
Nylon cords suddenly fire out, and the land is lowered to the martian surface. Once it is on the ground, pyrotechnically fired blades sever the ropes, and the descent state flies a safe distance, impacting the Martian surface.
A final thought about the landing from Hartvigsen, “One concern is being damaged or stranded on landing. This mission uses a new technology called TRN for terrain relative navigation. Cameras on board identify the location, compare it to a map in memory and then maneuver to a safe touchdown spot. We don’t want to land on a rock or in a crater where we can’t move or on a steep slope where the rover could roll. The exact location of the landing won’t be known until it arrives, but there is an expected landing ellipse of approximately 10 km across that has a ~99% probability of containing the landing site. The project scientists are placing their guesses of the location for bragging rights, a nerdy equivalent to putting odds on a sporting event. The map looks a bit like a dartboard with all the guesses. Once down safely, the process of checking out all the systems will take weeks, during which time the Ingenuity helicopter will be making its own history.
11 minutes later, we know on earth if Perseverance made it through the seven minutes of terror.