Wed. Sep 28th, 2022
A rover's-eye view of an ominous rocky landscape.

Panoramic image of Mars taken by Perseverance on February 20, 2021.

Never before, in all our millions of years, have humans directly observed a spacecraft on another planet. Until now.

On Monday, NASA released a video (embedded below) showing different viewpoints of Mars Perseverance’s descent to the surface of the red planet last week. A rear shell camera captured an image of the parachute deploying, and cameras on the descent platform and the rover itself captured the final seconds of the landing.

“I can and have watched those videos for hours,” said NASA’s Al Chen, the entry, descent and landing leader for Perseverance. “I find new things every time. I invite you to do the same.”

The first part of the video shows the tightly packed parachute released by mortar fire and blasted out at 160 km/h. It reaches full extension in a matter of seconds, at 50 feet above the spacecraft. It is then inflated in 0.7 seconds. There is no evidence of entanglement in the lines, a small miracle with two miles of lines in the parachute system. It is the first time scientists have observed a parachute up close in the thin atmosphere of Mars. “We will be studying this video for many, many years to come,” Chen said at a news conference.

Mars persistence lander.

Then, lower in the atmosphere, the visibility changes to show the heat shield falling away from the rover. White spots appear, probably frost. One of the eight springs connecting the heat shield to the rover is loose. The heat shield disappears and makes a smooth descent to the surface.

The final images are from a camera on the descent stage, looking down at the rover, and the rover, looking up at the descent stage. Perhaps most notable is this upward view, which shows the overhead crane maneuver where the descent brings the rover nearly to the surface and then quickly moves away. There is no exhaust plume from the thrusters on the descent stage – this is because hydrazine fuel produces a distinct plume of nitrogen and hydrogen.

Capturing these visceral images was not essential to the mission, but it was a bonus. The space agency used robust, out-of-the-box hardware to create these images. All told, about 30 GB of data was captured during the descent, totaling 23,000 images. Now that NASA has this information, it will be used to hone knowledge about future entry, descent and landing technology on Mars and other worlds in the solar system.

One landing problem highlighted in the new images is the dust that builds up through the descent phase as it approaches the surface of Mars and falls off the lander. It completely shrouds Perseverance in a thick cloud. This will be an important issue as NASA considers landing larger spacecraft and eventually human missions on the red planet.

“To my knowledge, there are no landing sites or barges on Mars,” Chen said. “This is a big challenge for us in the future, with heavier and heavier vehicles and bigger and bigger engines, which is why collecting this information is so important.”

The visual data will help scientists and engineers calibrate their models for dust, because they have accurate information about the thrust of the engines and how they pointed to the Martian surface.

More than just visual treats were released at the Perseverance press conference on Monday. For the first time, a rover recorded audio and sent it back to Earth, capturing what sounded like a gust of wind. “Who is going to compose the first piece of music with real Mars sound?” asked Thomas Zurbuchen, NASA’s chief of science. Who, indeed.

By akfire1

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