March 26, 2006
Making a Comfortable Home on the Moon
After a grueling day climbing the mountains of the moon, astronauts will need a place to kick back and relax. Larry Toups of the Johnson Space Center talks with Astrobiology Magazine about the challenges of designing a dwelling for the future moonwalkers.
NASA -- "Home available for short-term stay. Landscape is an airless but magnificent desolation. Closest grocery store is a quarter million miles away."Not many people would jump at such an ad, but for astronauts dreaming of lunar exploration, any kind of house would be an improvement over the cramped Apollo landing capsules. NASA currently is using mockups in an attempt to design the optimum lunar living rooms.
One of the structures, called the Lunar Habitation Vertical Mockup, is a three-story design that looks like tuna cans stacked on top of each other. The other -- the Lunar Habitation Horizontal Mockup -- has a long, cylindrical shape reminiscent of the International Space Station (ISS).
Both layouts include living quarters, a hygiene area, and a galley and central area for eating and recreation. They also have enough volume to add laboratories, workshops, and crew health and exercise stations.
Larry Toups is the lead in Habitation Systems at the Constellation Program's Advanced Projects Office at the Johnson Space Center. In this interview with Astrobiology Magazine's Leslie Mullen, he talks about the limits and challenges of designing the first frontier outpost on the moon.
Astrobiology Magazine (AM): In designing the lunar habitation modules, how long do you anticipate the astronauts will stay on the moon? For a few days? For several months?
Larry Toups (LT) : The Exploration Systems Architecture Study lays out a blueprint for a return to the moon in support of going to Mars. Within that blueprint are Sortie missions, which are very short missions that would land on the lunar surface. They've been referred to as "Apollo on steroids." Right now the missions consist of four crew members going down to selected sites along the lunar surface, and staying for upwards of a week, or maybe even ten days. It's hard right now to determine how long these missions would run, because we'll be learning as we do this. The Sortie missions will scout around and could plan to deliver something more substantial like a permanent outpost. Then crews composed of four to six people could stay continuously or intermittently at that outpost. Those crews would stay on the surface from 30 days to upwards of six months, very similar to a space station expedition.
AM: Are the habitats you're developing just for the extended stay outpost, or are you designing ones for the short scouting expeditions as well?
LT: Actually, the mock-ups we've developed could be used for both. But over the next year, our office will be looking closely at the Sortie missions. What we learn from looking at those missions possibly could be applied to the permanent outpost habitat. We might be able to use the assets developed for the Sortie missions, putting together a number of things that are delivered on those missions and creating an outpost from that.
AM: For long-term stays on the moon, what sort of radiation protection will the habitats have?
LT: Radiation protection will be very important "“ I think it will be one of the primary requirements for the lunar habitat. It was not a primary requirement for space station, at least not at the very start of its design and construction. The advantage that we have, going to a planetary surface, is that we can use the local resources to provide protection. In other words, we could use the lunar regolith itself, maybe using sandbags, and put it on top of the habitat to create a radiation barrier. We also could locate the internal water stowage around perimeter areas so that the water would provide protection. Even the location of certain system equipment that's needed might be configured so that the mass of the equipment might provide us radiation protection.
AM: How will the habitats produce oxygen and water? Do you anticipate you will get those supplies from the moon itself?
LT: Initially those materials will be brought with us. Over time, there probably will be small demonstrations of extracting oxygen and water from the lunar soil, and putting them to use as a gas or a liquid to help close our life support system. But as we foresee it right now, for the first generation habitat that we put down, lunar-generated resources would only supplement what we bring there. To supply the habitat with gases for life support, the interface would be the same whether you brought it with you or whether you produce something on the surface and plugged into it. You don't want to risk endangering the habitat or the crew by not being able to provide those vital resources. I think eventually the life support system would be based on using lunar resources, but that will depend on the success of demonstrations that we do over a period of time.
AM: Will the astronauts also have to bring their entire food supply, or do the habitat designs include gardens to grow food on the moon?
LT: That's similar to the life support systems, in that, initially, the crews would bring preserved food with them. It might be supplemented by plants, using herbs and other things to enhance the flavor of the food that they've brought.
AM: Does current astrobiology research, such as how organisms survive or adapt to extreme environments, inform the design of the lunar habitat at all?
LT: It should, I think, very strongly. Our office is trying to learn from previous experience. That includes not only missions like Apollo, Skylab, Mir, ISS, and the shuttle, but also work that is more in the science realm.
AM:I would also imagine that you're taking lessons not only from astrobiology research and past space missions, but also from Antarctic outposts and potentially the Biosphere project.
LT: Antarctic, yes. Also possibly the BioPlex project that we had at Johnson Space Center a number of years ago. As for Biosphere, I think there were some issues with the controls of that project. It was hard to determine what we actually learned from that data point.
AM:You mentioned a closed life support system for the lunar habitat. What sort of biological footprint do you expect the habitat will make, what with bacteria living in human waste and so forth?
LT: That's definitely an area of emphasis. In some of our preliminary work, we've identified planetary protection as an area that we need to work on. I met with John Rummel (NASA's planetary protection officer) a few weeks ago on that very issue. How does the life support system "“ which includes waste management, atmosphere revitalization, water purification, and even plant growth and the biomass that's a result of that "“ how does all that factor into a sustainable environment? This not only involves the interior of the habitat but, like you say, the footprint that we leave on the surface. So we're very aware of that, but those are things that we're just starting to look at, to be honest with you.
AM:There's probably no life on the moon, so at least you don't have to worry about contaminating any potential lunar life with Earth life.
LT: Right. That was essentially the message I got from the Planetary Protection Office. However, we still need to be aware of any potential by-products that are produced. They need to be either stored for reuse, or brought back to Earth.
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