On July 30, 2020, an Atlas V-541 rocket lifted off from Florida's Cape Canaveral carrying the Mars 2020 mission and its Perseverance rover on an approximately five-month journey to the red planet. After the rover lands on the Jezero Crater Feb. 18, 2021, the 2,260-pound (1,025 kilogram), 10-foot-long (3-meter-long) robotic vehicle will roam the crater, extracting chalk-sized pieces of Martian rock that eventually could reveal whether life once existed on the solar system's fourth planet from the sun.
Perseverance is the latest in a succession of Mars rovers that has included Spirit, Opportunity and Curiosity, which since arriving on the Martian surface in August 2012 has traveled 14.27 miles (22.97 kilometers) and in 2019 found evidence of an ancient oasis on the seemingly arid planet's Gale Crater.
NASA's plans for Perseverance to operate for at least one Martian year — 687 Earth days — and cover a distance of between 3 and 12 miles (5 and 20 kilometers).
Perseverance's most attention-getting scientific goal is to search for evidence of ancient microbial life on Mars. But as two NASA scientist explain, the mission is much more complex.
"The most significant aspect of this mission is that the mission represents the evolution of studying Mars — follow the water, understand habitability, and now search for the signs of ancient life," Michael Meyer, lead scientist for the Mars Exploration Program, and Mitch Schulte, a Mars 2020 Program Scientist, write in a joint message via email.
"However, we don't know what we will find until we get there, and that will be the most significant," the two scientists note. "Among the mission goals are to understand the geologic environment of the landing site and the search for biosignatures, and the rover is ably equipped to either find or at least identify the most promising samples that might have preserved biosignatures, and the extremely promising part, cache them to be brought back to Earth to be examined by the best instruments in the world."
NASA had to complete preparations for the launch in the middle of the COVID-19 pandemic. As NASA's website details, that situation required the project team to limit the number of personnel working together at any one time at the Jet Propulsion Laboratory in Pasadena, California, to the minimum needed, and workers had to practice social distancing, wear protective equipment and use hand sanitizer and other cleaning supplies. But on the science end, NASA workers were more concerned about maintaining the cleanliness of the planetary probe's sampling and caching system, which will handle Martian soil and rock samples
"The contamination control levels are unprecedented for any spacecraft and unachievable in most laboratories on Earth," Meyer and Schulte explain. "To build a sampling system to such ultra-clean standards, and keep the system clean, has been a real achievement. Of course, the proof of the pudding will be when the samples are returned to Earth. Technically, the rover is the most complex spacecraft sent to Mars, and designing and building the sample caching system was a substantial challenge. The only challenge posed by the pandemic has been keeping the team assembling the spacecraft and launch vehicle safe, which has been successful."
Perseverance will land on Jezero Crater, an area that researchers believe is a likely spot to find evidence of ancient microscopic organisms.
"Our orbital studies show that Jezero Crater was an ancient crater lake with a recognizable delta deposit, indicative of water flowing into a standing body of water," Meyer and Schulte write. "Life as we know it requires a liquid water environment to exist. In addition, a critical aspect is that the same site shows a high diversity of environments, a great place to sample multiple rock types that can tell us about the climate and geological history of the crater and the planet. On Earth, a delta is one type of deposit you would expect to have signs of life preserved. Furthermore, there are other tantalizing mineral deposits like the purported lakeshore has carbonate rocks, also a good place to have preserved evidence of life, if there was any."
While Perseverance's instruments will gather some data about the area from which Martian soil and rock samples are gathered, the samples eventually will be retrieved by a future mission and transported back to Earth for more extensive analysis.
The two NASA scientists explain that while the retrieval details are still being worked out, "the general plan is that in 2026 NASA and the European Space Agency will launch two missions, one a lander that will carry a fetch rover to get the samples and a rocket for lifting the samples off the red planet. The other mission will be an orbiter for capturing the sample container launched from the surface of Mars and then bringing the contained samples to Earth. Of course, we will know a fair amount about the samples and the area of Jezero Crater from which they come because of the science instruments on board the rover. Perseverance is well equipped to explore the region to understand the present and ancient environment, the details of each site explored, and specifically each rock or regolith from which the sample will have been collected."
We're likely to see some spectacular pictures of the Martian surface, since the rover is equipped with more cameras — 23 in all — than any previous Mars mission. "The premier imaging instrument, MastCam-Z, is a marked improvement to the impressive camera that's on Curiosity," the scientists write. "MastCam-Z has two 12-inch (30-centimeter) color filter wheels and, importantly, is able to zoom in up to 3 times on any object near and far."