Mars's large temperature variations and the microscopic expansion and contraction of Perseverance's arm could throw off PIXL's aim, so the hexapod automatically adjusts the instrument to get very close to the rock without touching it.
“To get the precision we need, we need to get down to the micrometre,” Allwood says, “getting close enough to the rock to make the hairs on the back of an engineer's neck stand up.”
Creating a mineral map
Once PIXL is in place, it opens the door for another AI system to step in. PIXL scans a postage-stamp-sized area of rock, firing its X-ray beam thousands of times to create a grid of microscopic dots, each of which reveals information about the chemical composition of the minerals present.
Minerals are crucial for answering important questions about Mars: In some rocks, scientists might be looking for carbonates, which could provide clues about how water formed the rocks, or phosphates, which could have nourished microbial life if it existed in Mars' past.
Scientists have no way of knowing in advance which of the hundreds of X-ray shots will find a particular mineral, but once the instrument finds a particular mineral, it can automatically stop and collect more data, a process called “long dwell.” As the system improves through machine learning, the list of minerals PIXL can focus on with long dwells continues to grow.
“PIXL is kind of a Swiss Army knife in that it can be configured depending on what scientists are looking for at any particular time,” said JPL's David Thompson, who helped develop the software. “Mars is the perfect place to test the AI, because there's regular, daily communication and the opportunity to make tweaks along the way.”
Future missions going deeper into the solar system will experience longer periods without contact than current missions at Mars, so there is strong interest in increasing autonomy for missions to explore and do science for the benefit of humanity.
Mission Details
The primary objective of the Perseverance mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the Martian geology and past climate, pave the way for human exploration of Mars, and will be the first mission to collect and store Martian rocks and regolith (broken rock and dust).
A subsequent NASA mission, in partnership with the European Space Agency (ESA), will send a spacecraft to Mars to collect sealed samples from the surface and bring them back to Earth for detailed analysis.
The Mars 2020 Perseverance mission is part of NASA's Moon-to-Mars exploration approach, which also includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet.
JPL is managed for NASA by the California Institute of Technology in Pasadena, California, and builds and operates the Perseverance rover.
For more information about Perseverance, please visit:
Mars Rover
