Perseverance mission scientist outlines rover’s instruments, mission
One month before the scheduled launch of NASA’s Perseverance Mars rover, Roger Wiens, who serves as both principal investigator of its SuperCam laser instrument and as co-investigator of its SHERLOC team, discussed the mission’s science instruments and its purpose in a virtual webinar presented by the Lunar and Planetary Institute (LPI).
In a presentation titled “NASA’s Perseverance Rover and the Prospect of Round-Trip Robotic Missions,” Wiens, of the Los Alamos National Laboratory, outlined the details of the first-ever Mars sample return mission in the context of the space agency’s decades-long exploration of the Red Planet.
Perseverance and the History of Mars Rover Exploration:
Beginning with Sojourner, NASA’s first Mars rover, which landed on the Red Planet in 1997, and continuing with Spirit and Opportunity in 2004 and Curiosity in 2012, Mars rover missions have progressed from focusing on simple to more complex aspects of the planet’s surface. Wiens described Curiosity as a “precursor to Perseverance,” noting the former carried over 150 pounds of payload, made up of 10 science instruments and a drill.
Perseverance, which will be collecting soil samples and storing them on the Martian surface for return by a future mission, is equipped with seven instruments, a helicopter, and caches to collect the samples. Its primary mission is to assess Mars’ biological potential, search for organic and biological materials, characterize the geology of the landing site, study past habitability and the role played by ancient surface water, and characterize hazards human astronauts will face on the planet.
Scheduled to land on Mars on February 18, 2021, Perseverance will touch down in Jezero Crater, where a lake existed 3.5 billion years ago. This crater is smaller than Gale Crater, Curiosity‘s landing site, but its inlet and outlet valleys and delta region make it an ideal place to search for life.
“We need to optimize the instruments on the rover because of the limits in time and size,” Wiens explained, noting the various instruments will conduct a range of rapid to slow and detailed analyses. A large number of samples collected will be subject to rapid analysis while a smaller number of samples will undergo more careful analysis and just a few samples will be analyzed in great detail.
First Helicopter on Mars:
The initial idea of sending a helicopter with the rover was rejected in proposal reviews. The helicopter was added only after the director of
NASA’s Jet Propulsion Laboratory (JPL) requested it be sent as a technical demonstration for future missions.
Mounted on the rover’s underside, the helicopter, named Ingenuity, will be capable of flying once a day for up to 300 meters. It can fly for at least one and one half minutes and operate autonomously.
“Helicopters open up new ways to explore the Red Planet,” Wiens emphasized, noting the presence of caves on the Martian surface. These are lava tubes that stretch for miles, and their main openings are holes at the top through which no rover can enter. A helicopter can study these caves, and Wiens expects they will be used on future missions to search the caves for organic materials.
On Earth, most life forms in caves are so primitive that they do not use photosynthesis. This is why caves are an ideal place to search for microbial life on Mars, Wiens said.
Similar to ChemCam on Curiosity, SuperCam, positioned on top of the rover, is equipped with three spectrometers. Capable of taking images and analyzing chemical composition and mineralogy, it will search for organic materials in surface rocks and soil.
SHERLOC, which stands for Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals, is a spectrometer that will conduct fine-scale imaging and use an ultraviolet laser to search for organic compounds. Mounted on a turret at the end of the rover’s robotic arm, it has a companion camera called WATSON, which will study rocks up close.
Placed inside the rover, the Mars Oxygen ISRU Experiment, or MOXIE, is a demonstration of technology that future astronauts can use to produce oxygen, crucial for both breathing and making rocket fuel.
MEDA, or the Mars Environment Dynamics Analyzer, will measure wind speed and direction, atmospheric pressure, relative humidity, air and ground temperatures, and ultraviolet radiation. Its sensors will be placed in various locations outside and inside the rover.
RIMFAX, the Radar Imager for Mars’ Subsurface Experiment, will use ground-penetrating radar to study layers of rock beneath the rover up to 60 meters down. Its radar antenna is placed on the rover’s lower rear.
Also mounted on the turret at the end of the robotic arm will be the Planetary Instrument for X-ray Lithochemistry or PIXR. This instrument will measure the amount and distribution of chemical elements in Martian rocks as part of the search for evidence of ancient microbial life.
MastCam-Z is the camera that will be mounted on Perseverance‘s mast. Equipped with numerous filters to cover a range of wavelengths, it is capable of zooming in on features, taking 3D pictures and video, and capturing panoramic color instruments.
Positioned at the rover’s front, the large drill will take surface samples that will be placed in hermetically sealed tubes currently installed inside the rover. At various locations, the rover will collect samples and drop the tubes on the ground. To prevent sample loss in the event the rover dies, tube samples will be dropped individually.
Locations where the tubes are placed will then be photographed extensively.
Sometime around 2027, another rover equipped with a fetch rover to collect the samples, will touch down on the site. A Mars ascent vehicle will launch the samples into low-Earth orbit, where they will be transferred to another spacecraft that will return them to Earth for study.
Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, NJ, who enjoys writing about astronomy and planetary science. She studied journalism at Douglass College, Rutgers University, and earned a Graduate Certificate of Science from Swinburne University’s Astronomy Online program. Her writings have been published online in The Atlantic, Astronomy magazine’s guest blog section, the UK Space Conference, the 2009 IAU General Assembly newspaper, The Space Reporter, and newsletters of various astronomy clubs. She is a member of the Cranford, NJ-based Amateur Astronomers, Inc. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD.