Science & Technology

Helps ensure a safe landing for the Mars 2020 Rover

The Mars 2020 Perseverance Rover is equipped with a lander vision system based on terrain-relative navigation. This is an advanced way to autonomously compare real-time images with preloaded maps to determine the position of the rover against danger in the landing area. The detour guidance algorithm and software can point the rover around these obstacles as needed. Credit: NASA / JPL-Caltech

How Two New Technologies Help Patience NASALanding on the surface of the most sophisticated rover ever Mars this month.

After nearly seven months of travel to Mars, NASA’s Perseverance Lance will land on the Jezero Crater on Red Planet on February 18, 2021. It is a steep expanse chosen for its scientific research and sampling potential.

But the very feature that makes this place attractive to scientists is that it is also a relatively dangerous place to land. This is a challenge that motivated rigorous testing on Earth for the Lunar Module Vision System (LVS), which expects Rover to land safely.

“Jezero is 28 miles wide, but within that range there are many potential dangers that Rover may encounter, such as hills, rocks, dunes, and the walls of the crater itself,” said the Lord. Robotics Andrew Johnson said. System engineer at NASA’s Jet Propulsion Laboratory in Southern California. “Therefore, landing on one of these dangers can have a devastating impact on the entire mission.”

enter Terrain-relative navigation (TRN) takes real-time photographs of Martian terrain, compares them to the onboard map of the landing area, and autonomously directs the rover to bypass known dangers and obstacles as needed. Is a mission-critical technology at the heart of LVS.

Masten Xombie VTVL system

Masten’s Xombie VTVL system was installed at Ranchpad in Mojave, CA in December 2014 to prepare for flight tests to help prove the capabilities of the Mars 2020 Patience Rover Mission lander vision system. Credit: Masten Space Systems

“For Mars 2020, LVS uses location information to figure out where the rover is relative to a safe place between these dangers, and one of those safe places is the rover. Is the place to land, “explained Johnson.

If Johnson seems confident that LVS will work to land patience safely, it will allow the rover to determine its position with respect to the ground. Accuracy About 200 feet or less. This low tolerance and high assurance is by design and is the result of extensive testing both in the lab and in the field.

“We have what we call a three-game winning streak in the test,” he explained. JPLSwatimohan, guidance, navigation, and control operations are leading Mars 2020.

A 2014 flight test on Masten’s Xombie VTVL system demonstrated the terrain-relative navigation and fuel-optimized large detour guidance (G-FOLD) capabilities of the lander vision system. The flight proved the ability of the system to autonomously divert to avoid danger during descent and adopt a newly calculated route to a safe landing site. Successful field testing has made it possible to turn the technology into a green light for inclusion in NASA’s Mars 2020 mission. Credit: NASA / JPL-Caltech

Mohan said the first two test areas (hardware and simulation) were done in the lab.

“Here we test all possible conditions and variables. Vacuum, vibration, temperature, electrical compatibility – we’ve matched the hardware to that pace,” Mohan said. “Next, we use simulations to model the various scenarios that software algorithms may encounter on Mars (too sunny, very dark days, windy days), and the system is irrespective of those conditions. Make sure it works as expected. “

However, the third, third field test requires actual flight to process the lab results more rigorously and provide a high degree of technical readiness for NASA’s mission. In early LVS flight tests, Johnson and his team installed the LVS on a helicopter and used it to automatically estimate the position of the vehicle in flight.

“The system was able to monitor a wide range of terrain, so it was technically prepared to some extent, but it didn’t have the same kind of descent as Perseverance,” Johnson said. “We also needed to demonstrate LVS with a rocket.”

This need was met by NASA’s Flight Opportunities program. The program facilitated two flights in 2014 in the Mojave Desert at Xombie of Masten Space Systems. This is a vertical takeoff and vertical landing (VTVL) system that functions like a lander. Flight tests have demonstrated LVS’s ability to autonomously divert and instruct Xombie to avoid dangers when descending by adopting a newly calculated route to a safe landing site. .. The early flight of Masten’s VTVL system also helped validate the algorithms and software used to calculate the optimal fuel orbit for planetary landings.

“The rocket test solved almost all the remaining questions and answered the key questions of LVS operation positively,” said the payload and pointing control system, which worked closely with Masten in the 2014 field test. Nikolas Trawny of JPL, an engineer, said. “At that time, we found that LVS worked during the high-speed vertical descent typical of a Mars landing.”

Johnson added that the in-orbit test actually raised the level of technical readiness and gave the final green light of acceptance for the Mars 2020 mission.

“The tests set up by Flight Opportunities were unprecedented within NASA at the time,” said Johnson. “But it has proven to be so valuable that it is now expected to perform these types of flight tests. For LVS, these rocket flights are our technology. It was the cornerstone of development efforts. “

With the technology accepted at Mars 2020, the mission team has begun building the final version of LVS flying in Perseverance. In 2019, a copy of the system flew in another helicopter demonstration in Death Valley, California, facilitated by NASA’s Technology Demonstration Mission Program. Helicopter flight provided the final check of multiple field tests over 6 years.

However, Mohan pointed out that even with these successful demonstrations, there would be more work to be done to ensure a safe landing. She is in mission control for landing and monitors the status of the system at every stage.

“In real life, you can always throw a curve ball, so during the cruising phase, monitor everything and check the camera’s power supply to make sure the data is flowing as expected.” Mohan said. “And when you get a signal from the rover,’I’m landing and on stable ground,’ you can celebrate. “

About flight opportunities

The Flight Opportunity Program is funded by NASA’s Space Technology Mission (STMD) and is managed by NASA’s Armstrong Flight Research Center in Edwards, California. NASA’s Ames Research Center in Silicon Valley, California, manages the solicitation and evaluation of technologies tested and demonstrated on commercial aircraft.

About technology demonstration mission

Also under the umbrella of STMD, the program is based at NASA’s Marshall Space Flight Center in Huntsville, Alabama. This program bridges the gap between scientific and engineering challenges and the technological innovations needed to overcome them, enabling powerful new space missions.

Mission details

The main purpose of Perseverance’s mission on Mars is astrobiology, including the search for signs of life of ancient microorganisms. Rover will be the first mission to characterize the geology and past climate of the planet, pave the way for human exploration of the Red Planet, and collect and cache Martian rocks and regoliths (broken rocks and dust). ..

Subsequent missions currently under consideration by NASA in collaboration with the European Space Agency will send spacecraft to Mars, collect these cached samples from the surface, and return them to Earth for further analysis.

The Mars 2020 mission is part of a larger program that includes a mission to the Moon as a way to prepare for human exploration of the Red Planet. NASA will be responsible for returning astronauts to the Moon by 2024, and through NASA will establish a sustainable human presence on and around the Moon by 2028. Artemis Moon Exploration Program..

JPL, managed by California Institute of Technology Caltech for NASA, builds and manages the operation of the Perseverance Rover.

Helps ensure a safe landing for the Mars 2020 Rover Helps ensure a safe landing for the Mars 2020 Rover

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