NASA on Friday released stunning new photographs from Perseverance, including one of the rover being gently lowered to the surface of Mars by a set of cables, the first time such a view has been captured.
The photo was released less than 24 hours after the Perseverance rover successfully touched down near an ancient river delta, where it will search for signs of ancient life and set aside the most promising rock samples for return to Earth in a decade. NASA equipped the spacecraft with a record 25 cameras and two microphones, many of which were turned on during Thursday’s descent.
The high-resolution still was extracted from a video taken by the descent stage of the spacecraft that had transported the rover from Earth.
At that moment, the descent stage was using its six-engined jetpack to slow to a speed of about 1.7 miles (2.7 kilometers) per hour as part of the “skycrane maneuver,” the final phase of landing.
The rover is shown in extraordinary detail just 6 1/2 feet (2 meters) off the ground, being lowered by cables attached to an overhead sky crane, the red dust kicked up by rocket engines. NASA’s Jet Propulsion Laboratory in Pasadena, California, promises more photos in the next few days and possibly also an audio recording of the descent.
“This is something that we’ve never seen before,” flight system engineer Aaron Stehura noted at a news conference. “It was stunning, and the team was awestruck. There’s just a feeling of victory that we were able to capture these and share it with the world.”
Chief engineer Adam Steltzner called the picture “iconic,” putting it right up there with photos of Apollo 11’s Buzz Aldrin on the moon, Saturn as seen by Voyager 1, and the Hubble Space Telescope’s “pillars of creation” shot.
A number of thumbnail images have been beamed down so far, too many to count, said Pauline Hwang, strategic mission manager for surface operations. “The team went wild” at seeing these first pictures, she said.
The picture is so clear and detailed that deputy project scientist Katie Stack Morgan at first thought she was looking at a photo from an animation. “Then I did a double take and said: `That’s the actual rover!’ ”
The vehicle is healthy, according to officials, after landing on a flat, safe surface in Jezero Crater with just 1 degree of tilt and relatively small rocks nearby. For now, the systems still are being checked. It will be at least a week before the rover starts driving.
The river delta — awash 3 billion to 4 billion years ago — is just over 1 mile (2 kilometers) away. Scientists consider it the most likely place to find rocks with evidence of past microscopic life.
Another photo of Perseverance’s front right wheel, near rocks full of holes, already has scientists salivating. They’re eager to learn whether these rocks are volcanic or sedimentary.
It’s the ninth time that NASA has successfully landed on Mars — and the fifth rover.
As it did with 2012’s Curiosity rover — still roaming 2,300 miles (3,750 kilometers) away — NASA’s Mars Reconnaissance Orbiter photographed Perseverance descending beneath its massive parachute. In each case, the spacecraft and chute resembled specks.
Curiosity’s cameras caught a stop-motion movie of the last two minutes its descent, but the images were small and fuzzy. NASA loaded up the heftier Perseverance and its descent stage with more and better cameras, and made sure they were turned on for the entire seven-minute plunge through the Martian atmosphere.
China will attempt to land its own much smaller rover in late spring. It’s been orbiting Mars for 1 1/2 weeks. The United Arab Emirates also put a spacecraft into Martian orbit last week.
Atmospheric entry
Ten minutes before entering the Martian atmosphere, the spacecraft shed its cruise stage that supplied the fuel tanks, radios and solar panels on the voyage.
It was left with just a protective aeroshell, carrying the rover and descent stage, and it fired thrusters to make sure its heat shield was forward-facing.
At about 80 miles (130 kilometers) altitude, it careened into the atmosphere and things started to get hot: Peak heating occurred about 80 seconds in, when the heat shield surface reached 2,370 degrees Fahrenheit (about 1,300 degrees Celsius).
Perseverance was tucked away safely in the aeroshell, only experiencing room temperature.
Parachute deployment
Once the spacecraft slowed down to less than 1,000 miles (1,600 kilometers) an hour, it was time to deploy the 70.5 feet (21.5 meters) wide supersonic parachute at an altitude of seven miles (11 kilometers).
Perseverance deployed a new technology called Range Trigger that decides the precise moment to deploy, based on the craft’s position relative to the landing site.
Asked to name the single most critical event, NASA’s EDL lead Allen Chen said: “Obviously there’s a lot of concentrated risk in supersonic parachute opening.”
To try out its new design, NASA had to carry out extensive supersonic parachute testing from high altitudes here on Earth, a field of research that had been dormant since the 1970s.
Heat shield separation
Next, the spacecraft jettisoned its heat shield, around 20 seconds after the parachute was deployed. The rover was exposed to the atmosphere for the first time, and used a landing radar to bounce signals off the surface and calculate its precise altitude.
The mission also saw another technology deployed for the first time: The “Terrain Relative Navigation” (TRN) system that uses a special camera to identify surface features and compare them to an onboard map where engineers pre-programmed the safest landing sites.
Illustration of the Perseverance rover, with its heat shield facing the planet, as it begins its descent through the Martian atmosphere. (NASA/JPL-Caltech via AP)
“That gives our vehicle eyes, and the ability to really see where she’s going and figure out where she is,” said Chen.
Powered descent
In the thin atmosphere of Mars, the parachute only got the vehicle down to 200 miles (300 kilometers) per hour — so Perseverance had to cut the chute loose, dispense with its back shell, and use rocket thrusters to ease itself down.
It did this using an eight-engined jetpack that’s installed directly above the rover and fired up at around 6,900 feet (2,100 meters) above the surface.
The vehicle had to tilt right away in order to avoid the falling parachute and back shell, then used its sophisticated systems to continue its descent.
Skycrane
With 12 seconds to go, at a height of 66 feet (20 meters), the rocket-powered descent stage lowered the rover down to the ground using long cables in a maneuver called “skycrane.”
The rover locked its legs and wheels into a landing position and touched the ground at a little less than two miles (1.2 kilometers) an hour, as the descent stage flew off and made its own controlled landing.
A full-scale model of the Mars 2020 Mission Perseverance Rover is displayed for the media at NASA’s Jet Propulsion Laboratory (JPL) Wednesday, Feb. 17, 2021, in Pasadena, California (AP Photo/Damian Dovarganes)
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2021-02-20 09:49:24Z
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