Mars 2020’s Perseverance rover is geared up with a lander vision system based upon terrain-relative navigation, a sophisticated approach of autonomously comparing real-time images to preloaded maps that figure out the rover’s position relative to risks in the landing location. Divert assistance algorithms and software application can then direct the rover around those challenges if required. Credit: NASA/JPL-Caltech
How 2 brand-new innovations will assist Perseverance, NASA’s most advanced rover yet, touch down onto the surface area of Mars this month.
After an almost seven-month journey to Mars, NASA’s Perseverance rover is slated to land at the Red Planet’s Jezero Crater on February 18, 2021, a rugged stretch picked for its clinical research study and sample collection possibilities.
But the really includes that make the website interesting to researchers likewise make it a reasonably unsafe location to land – a difficulty that has actually inspired extensive screening here on Earth for the lander vision system (LVS) that the rover will depend on to securely touch down.
“Jezero is 28 miles wide, but within that expanse there are a lot of potential hazards the rover could encounter: hills, rock fields, dunes, the walls of the crater itself, to name just a few,” stated Andrew Johnson, primary robotics systems engineer at NASA’s Jet Propulsion Laboratory in Southern California. “So, if you land on one of those hazards, it could be catastrophic to the whole mission.”
Enter Terrain-Relative Navigation (TRN), the mission-critical innovation at the heart of the LVS that records images of the Mars surface in genuine time and compares them with onboard maps of the landing location, autonomously directing the rover to divert around understood risks and challenges as required.
Masten’s Xombie VTVL system rests on a launchpad in Mojave, California in December 2014, gotten ready for a flight test that would assist show lander vision system abilities for the Mars 2020 Perseverance rover objective. Credit: Masten Space Systems
“For Mars 2020, LVS will use the position information to figure out where the rover is relative to safe spots between those hazards. And in one of those safe spots is where the rover will touch down,” described Johnson.
If Johnson sounds positive that LVS will work to land Perseverance securely, that’s since it enables the rover to identify its position relative to the ground with an precision of about 200 feet or less. That low margin of mistake and high degree of guarantee are by style, and the outcome of substantial screening both in the laboratory and in the field.
“We have what we call the trifecta of testing,” described JPL’s Swati Mohan, assistance, navigation, and control operations lead for Mars 2020.
2014 flight tests on Masten’s Xombie VTVL system showed the lander vision system’s terrain-relative navigation and fuel-optimal big divert assistance (G-FOLD) abilities. The flights showed the system’s capability to autonomously alter course to prevent risks on descent and embrace a freshly determined course to a safe landing website. The effective field tests allowed the innovation to be greenlighted for addition on NASA’s Mars 2020 objective. Credit: NASA/JPL-Caltech
Mohan stated that the very first 2 screening locations – hardware and simulation – were performed in a laboratory.
“That’s where we test every condition and variable we can. Vacuum, vibration, temperature, electrical compatibility – we put the hardware through its paces,” stated Mohan. “Then with simulation, we model various scenarios that the software algorithms may encounter on Mars – a too-sunny day, very dark day, windy day – and we make sure the system behaves as expected regardless of those conditions.”
But the 3rd piece of the trifecta – the field tests – need real flights to put the laboratory results through additional rigor and supply a high level of technical preparedness for NASA objectives. For LVS’s early flight tests, Johnson and group installed the LVS to a helicopter and utilized it to approximate the car’s position immediately as it was flying.
“That got us to a certain level of technical readiness because the system could monitor a wide range of terrain, but it didn’t have the same kind of descent that Perseverance will have,” stated Johnson. “There was also a need to demonstrate LVS on a rocket.”
That requirement was satisfied by NASA’s Flight Opportunities program, which helped with 2 2014 flights in the Mojave Desert on Masten Space Systems’ Xombie – a vertical departure and vertical landing (VTVL) system that works likewise to a lander. The flight tests showed LVS’s capability to direct Xombie to autonomously alter course and prevent risks on descent by embracing a freshly determined course to a safe landing website. Earlier flights on Masten’s VTVL system likewise assisted verify algorithms and software application utilized to compute fuel-optimal trajectories for planetary landings.
“Testing on the rocket laid pretty much all remaining doubts to rest and answered a critical question for the LVS operation affirmatively,” stated JPL’s Nikolas Trawny, a payload and pointing control systems engineer who worked carefully with Masten on the 2014 field tests. “It was then that we knew LVS would work during the high-speed vertical descent typical of Mars landings.”
Johnson included that the suborbital screening in truth increased the innovation preparedness level to get the last thumbs-up of approval into the Mars 2020 objective.
“The testing that Flight Opportunities is set up to provide was really unprecedented within NASA at the time,” stated Johnson. “But it’s proven so valuable that it’s now becoming expected to do these types of flight tests. For LVS, those rocket flights were the capstone of our technology development effort.”
With the innovation accepted for Mars 2020, the objective group started to construct the last variation of LVS that would fly on Perseverance. In 2019, a copy of that system flew on another helicopter presentation in Death Valley, California, helped with by NASA’s Technology Demonstration Missions program. The helicopter flight supplied a last look at over six-years of numerous field tests.
But Mohan mentioned that even with these effective presentations, there will be more work to do to guarantee a safe landing. She’ll be at Mission Control for the landing, keeping an eye on the health of the system every action of the method.
“Real life can always throw you curve balls. So, we’ll be monitoring everything during the cruise phase, checking power to the camera, making sure the data is flowing as expected,” Mohan stated. “And once we get that signal from the rover that says, ‘I’ve landed and I’m on stable ground,’ then we can celebrate.”
About Flight Opportunities
The Flight Opportunities program is moneyed by NASA’s Space Technology Mission Directorate (STMD) and handled at NASA’s Armstrong Flight Research Center in Edwards, California. NASA’s Ames Research Center in California’s Silicon Valley handles the solicitation and assessment of innovations to be checked and shown on industrial flight automobiles.
About Technology Demonstration Missions
Also under the umbrella of STMD, the program is based at NASA’s Marshall Space Flight Center in Huntsville, Alabama. The program bridges the space in between clinical and engineering obstacles and the technological developments required to conquer them, allowing robust brand-new area objectives.
More About the Mission
A crucial goal for Perseverance’s objective on Mars is astrobiology, consisting of the look for indications of ancient microbial life. The rover will identify the world’s geology and previous environment, lead the way for human expedition of the Red Planet, and be the very first objective to gather and cache Martian rock and regolith (damaged rock and dust).
Subsequent objectives, presently under factor to consider by NASA in cooperation with the European Space Agency, would send out spacecraft to Mars to gather these cached samples from the surface area and return them to Earth for thorough analysis.
The Mars 2020 objective belongs to a bigger program that consists of objectives to the Moon as a method to get ready for human expedition of the Red Planet. Charged with returning astronauts to the Moon by 2024, NASA will develop a continual human existence on and around the Moon by 2028 through NASA’s Artemis lunar expedition strategies.
JPL, which is handled for NASA by Caltech in Pasadena, California, developed and handles operations of the Perseverance rover.
