Written by Steve Gorman
LOS ANGELES (Reuters) – When NASA’s Mars spacecraft, an automated astronomical biology laboratory packed inside a space capsule, reached the final stage of its seven-month journey from Earth this week, it is set to sound a radio alert as it approaches Earth. Thin Mars atmosphere.
By the time that signal reaches mission managers some 127 million miles (204 million kilometers) away at the Jet Propulsion Laboratory (JPL) near Los Angeles, the persistence will have already landed on the Red Planet – and hopefully, one piece.
The six-wheeled spacecraft is expected to take seven minutes to descend from the top of the Martian atmosphere to the surface of the planet in less time than the radio transmission time of over 11 minutes to Earth. Thus, the self-guided landing of the spacecraft is scheduled to take place on Thursday during a time interval that JPL engineers affectionately refer to as “seven minutes of terror.”
Al Chen, head of the JPL landing and landing team, described it as the riskiest and most dangerous part of the $ 2.7 billion mission.
“Success is never guaranteed,” Chen said in a recent press release. “This is especially true when we’re trying to take down the largest, heaviest, and most complex rover we’ve built at the most dangerous site we’ve ever attempted to land.”
Much depends on the result. Building on the discoveries of nearly 20 American trips to Mars dating back to the 1965 Mariner 4 flight, persistence may pave the way for scientists to definitively show whether life exists outside Earth, while paving the way for final human missions to the fourth planet from the Sun. A safe landing, as always, comes first.
Success will hinge on a complex series of events unfolding without hindrance – from the inflating of a giant supersonic parachute to the deployment of a jet-powered “sky lift” that will descend to a safe landing point and hover above the surface while the rover is lowered to the ground on a rope.
“Perseverance should do all this alone,” Chen said. “We cannot help her during this period.”
If all goes as planned, a NASA team will receive a radio tracking signal just before 1 p.m. PST confirming that the persistence has landed on Mars soil on the edge of an ancient river delta and an ancient lake bed.
Science is on the surface
From there, the battery-powered vehicle, roughly the size of a small SUV, will begin the primary goal of its two-year mission – to engage a complex set of tools in the search for signs of microbial life that may have flourished on Mars billions of years ago.
Advanced electrical tools will drill samples of Martian rocks and seal them into tubes the size of cigars and eventually return them to Earth for further analysis – the first such samples humanity has ever collected from the surface of another planet.
There are two future missions to recover those samples and return them to Earth, and they are in the planning stages by NASA, in cooperation with the European Space Agency.
Perseverance, the fifth and most advanced spacecraft that NASA has sent to Mars since Sojourner in 1997, also includes many groundbreaking features that are not directly related to space biology.
Among them is a small unmanned helicopter, dubbed Ingenuity, which will experience a surface-to-surface powered flight in another world for the first time. If successful, the four-pound (1.8 kg) rotating bird could pave the way for low-altitude aerial surveillance of Mars during later missions.
Another experiment is a device for extracting pure oxygen from carbon dioxide in the Martian atmosphere, a tool that could prove invaluable to support future human life on Mars and to produce rocket fuel to transport astronauts to their homes.
“Amazing,” but deceptive
The mission’s first hurdle after a 293 million miles (472 million km) flight from Earth was to connect the rover to the Jerezo Crater floor, a 28-mile (45 km) viewing area that scientists believe may contain a rich array of fossilized microorganisms.
“It’s an amazing landing site,” project scientist Ken Farley told reporters on a conference call.
What makes the crater’s rugged terrain – deeply carved by long-vanished streams of liquid water – so confusing as a search site also makes it a subsidence area.
The landing sequence, an upgrade from NASA’s last rover mission in 2012, begins as the Perseverance, covered in a protective shell, penetrates the Martian atmosphere at 12,000 mph (19,300 km per hour), nearly 16 times the speed of sound on Earth.
After the parachute is deployed to slow its descent, the landing capsule is scheduled to drop the heat shield to launch the jet-propelled “sky lift” hovercraft with the rover installed on its stomach.
Once the parachute is removed, the sky crane’s jet thrusters are instantly adjusted, slowing its descent to a walking speed as it approaches the crater floor and self-travels to a smooth landing site, and turns away from rocks, cliffs and sand dunes.
The sky crane hovers over the roof, due to reduced tenacity on the nylon ropes, cutting the ropes when the rover wheels reach the surface, and then flying to crash a safe distance away.
Deputy Project Director Matthew Wallace said that if all worked, post-landing abundance would fully emerge in the JPL despite COVID-19 safety protocols that kept close contacts within mission control to a minimum.
“I don’t think COVID will be able to stop us from jumping up and down and hitting the fist,” Wallace said.
(Prepared by Steve Gorman in Los Angeles; Editing by Frank McGorty and Will Dunham)