This will be a test drive like no other.
An SUV-size rover will roll across a seemingly alien red landscape this week, climbing slopes and maneuvering over rocks and other obstacles for the sake of exploration.
But it’s happening in Pasadena, California – on Earth, not Mars.
The NASA Perseverance rover launched in July and is currently on its way to Mars, with an expected landing date of February 18, 2021. Considered NASA’s first astrobiology mission, Perseverance will search for signs of ancient microbial life on Mars and collect the first samples to be returned from Mars to Earth.
Its nearly identical twin on Earth, named OPTMISM, arrived at the Mars Yard last week. This red dirt field acts like a replica of the Martian landscape, and it’s located on the NASA Jet Propulsion Laboratory campus in Pasadena.
The OPTIMISM rover has hardware and software similar to Perseverance, so it’s a chance for the Mars rover engineers and drivers to run through tests on Earth before they use commands from Earth to drive Perseverance on Mars.
The Earth version of the rover moved into its garage next to the Mars Yard and passed its first driving test on a smooth surface last week. This week, it will face the Mars Yard, a hilly, uneven terrain designed to mimic the Mars landscape.
“Perseverance’s mobility team can’t wait to finally drive our test rover outside,” said Anais Zarifian, mobility test bed engineer at JPL, in a statement. “This is the test robot that comes closest to simulating the actual mission operations Perseverance will experience on Mars - with wheels, eyes, and brains all together - so this rover is going to be especially fun to work with.”
The OPTIMISM rover is incredibly similar to Perseverance in many ways. Both rovers have the same head, or remote sensing mast, top driving speed of 0.094 miles per hour (for reference, mosquitoes fly at about one mile per hour), mobility system and size.
Early next year, OPTIMISM will be outfitted with the same science instruments, rock and soil sample collection system, camera “eyes” and computer “brains” that Perseverance is carrying to Mars.
Driving on another planet
On Mars, Perseverance will be truly alone – apart from the Ingenuity helicopter. And the helicopter isn’t exactly a handyman that can fix any issues that pop up with the rover.
By testing the rover’s hardware and software on Earth in a similar landscape, engineers can test out commands they anticipate sending to Perseverance.
And as they discover things in the software, the rover team can even send software patches to Perseverance as it travels through space or once it lands on Mars.
But one key difference is that OPTIMISM isn’t going to Mars, so it can be plugged in for power rather than relying on the nuclear battery Perseverance carries. This means that OPTIMISM also has ethernet capabilities to send and receive data between itself and the engineers, rather than relying on the radios Perseverance uses to send and receive data across space.
And OPTIMISM will have to endure the heat of summer in Southern California, rather than the cold temperatures Perseverance will face on Mars, so it has a cooling system.
While Perseverance was named during a competition earlier this year by Alex Mather, a middle school student in Virginia, the name OPTIMISM comes from the team that put together the rover.
On the one hand, it’s an acronym: Operational Perseverance Twin for Integration of Mechanisms and Instruments Sent to Mars. But it’s also a bit of a mantra for the team.
“The Mars 2020 Perseverance test bed team’s motto is ‘No optimism allowed,’” said Matt Stumbo, the lead for the Vehicle System Test Bed rover on the test bed team, in a statement.
“So we named the test rover OPTIMISM to remind us of the work we have to do to fully test the system. Our job is to find problems, not just hope activities will work. As we work through the issues with OPTIMISM, we gain confidence in Perseverance’s capabilities and confidence in our ability to operate on Mars.”
The OPTIMISM rover is in good company in its new home at the Mars Yard, where the Curiosity rover’s twin MAGGIE also lives. Also known by its full name, the Mars Automated Giant Gizmo for Integrated Engineering test bed rover, MAGGIE has helped the Curiosity team determine driving and drilling strategies for the rover since it landed on Mars in 2012.
“Missions that are operating require high-fidelity replicas of their systems for testing,” Stumbo said. “The Curiosity mission has learned lessons from MAGGIE that were impossible to learn any other way. Now that we have OPTIMISM, the Perseverance mission is well equipped to learn what they need to succeed on Mars.”