NASA is evaluating a first human stay on the surface of Mars that would last 30 Earth days or so.
Scientists and engineers are debating how to best use that month on the Red Planet. Should the Mars explorers plant a flag, just try to stay alive, conduct valuable science work or prioritize setting up equipment for the next human Mars landing team? However that epic mission shakes out, site selection will be critical, and hauling select gear on the first outing will likely set the framework for future human exploration of the Red Planet.
Last month, NASA held a Science Objectives for Human Exploration of Mars Workshop to discuss the highest-priority science objectives for a crewed expedition to the Red Planet. The agency has also begun outlining several different potential concepts of operation that will enable that science.
One outcome from the meeting is the identification of certain categories of science work that could take advantage of a crewed surface mission, whether or not the astronauts actually need to operate the equipment. As it turns out, there's lots of science that can be done, even if the astronauts have to spend most of their time working to stay alive and stay healthy.
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Pre-positioned robotic assets
"My impression from the workshop was that, while 30 days provides a very tight constraint on science operations, if we effectively utilize pre-positioned robotic assets, we can potentially reduce the risk to achieving science objectives which is inherent in such a short surface mission," said Paul Niles, a planetary scientist within the Astromaterials Research and Exploration Science Division at NASA's Johnson Space Center (JSC) in Houston.
"There remains a lot of work to do to better understand whether the types of missions we discussed are feasible," Niles told Space.com.
The workshop, which was held from May 4 to May 6 in Denver, brought scientific and engineering expertise together, said Michelle Rucker, leader of the Mars Integration Group that is developing crewed Mars mission concepts at JSC.
"We brought the communities together to talk about how to optimize the science return for a shorter-duration mission," Rucker said.
Mars: What we know about the Red Planet
'A little twitchy'
Rucker said that the distance to Mars means that a crewed surface mission would last a total of at least two years roundtrip, and maybe longer.
"We've never put someone in space for two years. That's a subtlety that people miss because they see human spaceflight now as so routine," Rucker said. "We have a few data points at a year. But engineers get a little twitchy when you get out beyond their experience base."
Over the last few years, Rucker and colleagues have been challenged to look at ways to get humans to Mars and back again as speedily as possible while still carrying out substantial science work while crews are on the surface.
"We knew that there would be a lot of concern that roughly a month on Mars wouldn't be enough time to get much done," she said.
But the science work wouldn't have to end when the astronauts leave the Red Planet, Rucker advised.
"We'll have pre-deployed cargo so there are some robotic opportunities when the crew arrives to set up equipment," she said. "And then once the crew leaves, presumably, we will have a lot of assets that we can leave behind. Humans are pretty high-maintenance. We need a lot of power, communication infrastructure … and all that infrastructure would be available to continue the science after the crew comes back to Earth."
Stephen Hoffman is a Houston-based senior engineer specialist for The Aerospace Corporation. He has years of experience in devising crewed Mars exploration scenarios, recently scoping out daily activity timelines for two astronauts occupying the Red Planet for 30 Martian days, or sols. (A sol is just a tad longer than a day on Earth, lasting about 24 hours and 39 minutes).
"If you look back at human spaceflight in the past, the first time you do something it's never the most ambitious thing," Hoffman said.
He underscored the short stay on the lunar surface of Apollo 11 in 1969, contrasting it with later Apollo "J" missions designed for longer sorties by moonwalkers. Similarly, Hoffman said, the first space shuttle mission was a scant 36-orbit flight that appraised the vehicle's performance, whereas follow-on shuttle missions were longer and multifaceted.
"This 30-sol mission on Mars kind of fits the bill," Hoffman said. "It's long enough to test out the first time that humans are on Mars, the first time we have EVA [extravehicular activity] spacesuits on Mars, the first time we have pressurized rovers on Mars. There's always a first time on Mars," Hoffman said.
Such newer studies represent a departure, he added. Planners of potential astronaut missions to Mars have generally investigated long surface stays on the very first try — 300 sols or 18 months of crew time, for example.
What has to be taken into account is that crews won't perform work outside their habitats 24/7, experts have stressed. First, Red Planet explorers will need to adapt to Mars gravity, which is about 40% that on Earth's surface, after a lengthy trek in microgravity. (It currently takes about eight months to fly from our planet to Mars.)
Mars astronauts will also need to eat, sleep, talk to doctors, and unplug and listen to music and relax at the end of the day, Rucker added. "Is it important to just dip your toe in the water and start exploring, or wait until it is perfect?"
Rucker senses a "culture change" between the science community, robotic exploration aficionados and the fact that Mars is becoming increasingly in sight as a human destination. "I think the fact is that we know more about Mars today than we knew about the moon when we first landed humans there."
The recent Denver workshop was a step forward in shaping a consensus that a month on Mars "is not a throwaway, not a 'plant the flag, take a picture and go home' kind of a thing," Hoffman said. A vital question to be fleshed out, he said, is what is being asked of that first Mars landing crew as groundwork in preparation for many more, and longer-term, human stays on the Red Planet.
Leonard David is author of the book "Moon Rush: The New Space Race," published by National Geographic in May 2019. A longtime writer for Space.com, David has been reporting on the space industry for more than five decades. Follow us on Twitter @Spacedotcom or on Facebook.