Perseverance, the centrepiece of NASA’s $2.7 billion Mars 2020 mission, touched down inside the Red Planet’s Jezero Crater on February 18th, 2021. Once it’s fully up and running, the car-sized robot will search for evidence of past microbial life and collect several samples for future return to Earth, among other ambitious tasks.
A key objective of Perseverance’s mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterise the planet’s geology and past climate, paving the way for human exploration of Mars. It will be the first mission to collect and cache Martian rock and regolith. NASA’s Perseverance rover carries eleven metal additively manufactured parts.
Andre Pate, the group lead for Additive Manufacturing at NASA’s Jet Propulsion Laboratory (JPL) in Southern California, commented, “Flying these parts to Mars is a huge milestone that opens the door a little more for Additive Manufacturing in the space industry.” NASA explains that Curiosity, Perseverance’s predecessor, was the first mission to take Additive Manufacturing to Mars when it landed in 2012 with an additively manufactured ceramic part inside the rover’s oven-like Sample Analysis at Mars (SAM) instrument. NASA has since continued to test AM for use in spacecraft to ensure the parts’ reliability is well understood.
NASA’s JPL is managed by Caltech in Pasadena, Southern California, which builds and manages operations of the Perseverance and Curiosity rovers.
Of the eleven metal additively manufactured parts travelling to Mars, five are within Perseverance’s Planetary Instrument for X-ray Lithochemistry (PIXL). This device helps the rover seek out signs of fossilised microbial life by aiming X-ray beams at rock surfaces to analyse them.
To make that instrument as light as possible, the JPL team designed PIXL’s two-piece titanium shell, a mounting frame, and two support struts that secure the shell to the end of the arm to be hollow and extremely thin. The parts, which were additively manufactured by Carpenter Additive, are reported to have three or four times less mass than if they’d been produced conventionally.
“In a very real sense, 3D printing made this instrument possible,” stated Michael Schein, PIXL’s lead mechanical engineer at JPL. “These techniques allowed us to achieve a low-mass and high-precision pointing that could not be made with conventional fabrication.”
Perseverance’s six other metal additively manufactured parts can be found in an instrument called the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE). This device will test technology that, in the future, could produce industrial quantities of oxygen to create rocket propellant on Mars, helping astronauts launch back to Earth. To create oxygen, MOXIE heats Martian air up to nearly 800°C. Within the device are six heat exchangers – palm-size nickel-alloy plates that protect key parts of the instrument from the effects of high temperatures. NASA explains that while a convention¬ally machined heat exchanger would need to be made out of two parts and welded together, MOXIE’s were each additively manufactured as a single piece.