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Tap into the experiences of NASA’s technical workforce as they develop missions to explore distant worlds—from the Moon to Mars, from Titan to Psyche. Learn how they advance technology to make aviation on Earth faster, quieter and more fuel efficient. Each biweekly episode celebrates program and project managers, engineers, scientists and thought leaders working on multiple fronts to advance aeronautics and space exploration in a bold new era of discovery. New episodes are released bi-weekly on Wednesdays. 

NASA’s Tiffany Nickens discusses habitats being developed for living on the lunar surface and traveling to Mars.

As NASA prepares to land the first woman and first person of color on the lunar South Pole, the agency is working with industry to refine ideas for habitation systems and designs for the lunar Surface Habitat and the Mars Transit Habitat. The Exploration Systems Development Mission Directorate’s Habitation Systems Development team recently published Moon to Mars (M2M) Habitation Considerations, a technical memorandum that addresses ground rules and assumptions, functional allocations, and logistics for the lunar Surface Habitat and Mars Transit Habitat.

In this episode of Small Steps, Giant Leaps, you’ll learn about:

  • Surface Habitat support of robust science on the lunar surface
  • Mars Transit Habitat support of astronauts’ physical and emotional health during travel to Mars
  • Highlights of the Moon to Mars (M2M) Habitation Considerations tech memo


Related Resources


Tech Memo: Moon to Mars (M2M) Habitation Considerations


Artemis Base Camp

APPEL Courses:

Creativity and Innovation (APPEL-vC&I)

Writing for Technical Professionals (APPEL-vTW)

Requirements Development and Management (APPEL-vREQ)

Risk Management I (APPEL-vRM I)


Tiffany Nickens Credit: NASA

Tiffany Nickens
Credit: NASA

Tiffany Nickens serves as the Systems Engineering & Integration (SE&I) Lead for NASA’s Habitation Formulation Team supporting the Exploration Systems Development Mission Directorate (ESDMD). In this role, Nickens supports technical and programmatic integration of habitation government reference architectures as well as engagement with commercial partners. She previously supported Avionics/Flight Software design and development on the Space Launch System (SLS) program. Prior to joining NASA in 2017, Nickens worked in the private sector on primary flight displays for rotorcraft and fixed-wing aircraft. She received a bachelor’s in human factors and a master’s in human factors and systems engineering from Embry-Riddle Aeronautical University.


Tiffany Nickens: We’ve got to find a way to be innovative, to find new technologies, more efficient means to design and architect these habitats to kind of meet these mass challenges.

We want to do that in that lunar environment to prep, to refine and then be ready for eventually going to Mars.

Deana Nunley (Host): Welcome to Small Steps, Giant Leaps, a NASA APPEL Knowledge Services podcast where we tap into project experiences to share best practices, lessons learned and novel ideas.

I’m Deana Nunley.

As part of the Artemis Program plan to send the first woman and first person of color to the surface of the Moon, NASA is working with commercial and international partners to establish a permanent human presence on the Moon to uncover new scientific discoveries and lay the foundation for private companies to build a lunar economy.

An Artemis Base Camp on the Moon’s surface and the Gateway in lunar orbit are a couple of key elements that will allow robots and astronauts to explore more and conduct science. The agency will use what we learn on the Moon to prepare for humanity’s next giant leap – sending astronauts to Mars.

Today on the podcast we’re looking at considerations for Moon to Mars habitation. Tiffany Nickens is the Systems Engineering and Integration Lead for NASA’s Habitation Formulation Team.

Tiffany, thanks for joining us.

Nickens: Yeah, thanks for having me.

Host: Could you give us a brief overview of the Habitation Systems Development team and your role?

Nickens: Sure. Habitation Systems Development team really covers a few different areas, including Vehicle System Integration support, or VSI, for the Gateway Program. And then we also have a portion supporting what we call habitation formulation. And the Habitation Formulation team leads the agency’s concept development for habitats, including lunar Surface Habitat and the Transit Habitat that’ll take the first crew to Mars, which is a pretty exciting opportunity there. And we also engage with commercial industry through our NextSTEP Broad Agency Announcements, or NextSTEP BAA, under Appendix A as well as different Space Act agreements. My support to this is to the Habitation Formulation team as the Systems Engineering and Integration Lead, or the SE&I Lead.

Host: What are some ways that living on the Moon is different from living on say the International Space Station?

Nickens: Sure. The biggest difference is really going to come down to gravity. Living on the Moon, crew will now operate in 1/6 gravity. And so there will certainly be very similar challenges to operating on ISS but maybe with a slightly different twist. You think about operating in 1/6 gravity for things like outfitting your habitats or logistics transfer. On ISS, we can kind of quickly and easily push large pieces of material back and forth but here in this kind of gravity environment we’ll have to hoist a logistics container up and down multiple floors or just kind of physically manipulate things in and out of the habitat that we maybe didn’t quite have to go through on ISS. So, how do we do that in a safe, effective way such that we aren’t putting crew in a dangerous situation.

Host: When we go back to the Moon, astronauts will be conducting more robust science on the lunar surface than what NASA did in Apollo. How will the Surface Habitat support that science mission?

Nickens: Sure. When we go back to the Moon, we’re going back in this sustained way, this long-term presence on the surface. And so, the Surface Habitat will be able to support a broader range of science and utilization capability, given the larger volume to house the equipment and for crew to come in and be able to perform those activities. We’ll also be able to have the opportunity to run long duration studies over maybe weeks or months or even years, since we’ll have that again, kind of sustained presence for up to 15 years. Of course, we still have work to do to kind of understand what types of exploration science and utilization we want to do. But having that Surface Habitat there will really kind of open the door to the possibilities of what sorts of science and exploration activities we might want to do that we just were limited in prior Apollo missions.

Host: You mentioned that your team is also working on the Mars Transit Habitat. Would you say it’s more like the lunar Surface Habitat or ISS? And what are some of the similarities and differences?

Nickens: Yeah. I think maybe one of the things that is kind of unique about the Transit Habitat is prior to going out on a Mars mission, we’ll stay docked at Gateway for the first five or more years of the Transit Habitat’s life. And so, we’ll be orbiting with the Gateway in this cislunar orbit to perform things like shakedown missions, to check out our systems, make sure everything is working the way we expected them to. But it’ll also serve as a platform to perform Mars analogs of increasing duration. In those early years, we’ll be able to operate in this microgravity environment, kind of a proving ground where we prepare for Mars and future exploration missions. In that respect, I’d say it’s probably more like ISS. ISS is this really wonderful proving ground of new technology developments, of analogs.

And so, Transit Habitat is kind of again, kind of in these early years, be very similar in that respect where we are able to really proof out those new technologies, make sure our CONOPS are locked down, that we have a good feel for what crew may see, what our systems may operate like prior to heading out into Mars. But ultimately, they all carry capabilities and technologies and knowledge base that feed forward to Mars. In that respect, maybe they are Surface Habitat and Transit and ISS definitely have that common thread with them, too.

Host: And so, on the way to Mars, astronauts will be confined to the spacecraft for the entire months-long journey there and back. How will the Transit Habitat support not only their physical well-being but their emotional health as well?

Nickens: Yeah. Great question. And I think sometimes that is lost when we’re designing these really complex pieces of hardware and software, these systems of systems. Sometimes we lose sight of the most complex system on board, which is the crew. So, yeah, absolutely. We need to ensure that from a physical well-being, we have sufficient exercise capability and food. That’s another really key piece is crew will be going out for multiple years. You think about food fatigue. We’re going to be somewhat limited on what we can take with them. Looking at opportunities to just ensure crew are getting the nutrition, that they maintain a good, healthy appetite while they’re in transit.

But as far as their emotional health, absolutely. It really comes down to, do they have meaningful work to do, things that continue to inspire them to get out of bed? To want to continue on and persevere because they’ll be in a constrained volume for a long period of time and those can certainly have some effects to your mental, your emotional health. Being able to offer them ways to just exercise their mind in different ways, having crew activities, having maybe movie nights, having potentially even dedicated holidays, whether they’re made-up holidays or real holidays, they seem like kind of, I don’t know, maybe silly things, but they are important things that they can celebrate and look forward to as some little milestone to reach.

And so being able to communicate with home too, that’s another important key is enabling them to continue making those connections to family and friends at home. All of those things together play back into the systems we build, the way we design and architect these habitats. And so, keeping those things in mind, that it’s not just about hardware and software, that there’s also this kind of ‘crew-ware,’ if that’s a word. These crew that we’ve got to kind of take into consideration as well.

Host: So interesting, Tiffany. And no one has lived in these places before. How are the assumptions made about what people will need to survive there?

Nickens: We perform studies. We study, we refine our assumptions and then we study again. Like that old saying, measure twice, cut once. It’s not easy the thing that we’re doing. Rocket science isn’t easy. Space travel isn’t easy. We’re exploring these new places that we’ve never been before, technologies we’ve never used before. Study, study, refine our assumptions. Looking at ways that we can do these analog missions on Earth, as much as we can. Leverage ISS and one day maybe even the new commercial LEO Destinations platform and eventually use the Moon to be that crossover. That place where we can continue growing our knowledge base. That’s really why we’re going back to the Moon is using it as a staging that we can exercise technologies that would be used in the Mars environment. The CONOPS, just the day-to-day motion of what crew may do and perform. We want to do that in that lunar environment to prep, to refine and then be ready for eventually going to Mars.

Host: And I understand that your team recently developed and released a technical memorandum on ground rules and assumptions for the lunar Surface Habitat and Mars Transit Habitat. What are some of the highlights? And what will the document be used for?

Nickens: Yeah. We’re pretty excited about this tech memo. For a while, we’ve wanted to really get out there the government’s latest thinking on ground rules and assumptions, on functional allocations and even logistics assumptions for both habitats. And embedded in the document, we’ve also put in little pieces here and there on current concept of operations, our current CONOPS that we know today just to help provide some contextual information to better inform industry partners’ concepts. And so there’s lots of great nuggets kind of embedded throughout the technical memo. I think some of the things the community will find are, we have pretty major mass constraints. As probably all things do, we’ve got to find a way to be innovative, to find new technologies, more efficient means to design and architect these habitats to kind of meet these mass challenges.

Of course, that’s one of our many technical challenges we need to figure out. But this, so the tech memo is really trying to just kind of lay that groundwork. And ultimately that’s why we developed the document. So, we’re already engaging with some commercial partners, but we saw this as an opportunity to provide further outreach to potential partners interested in habitation or even habitation systems because at the end of the day, we aren’t a black box. This isn’t one big habitat black box. We are made up of many, many hundreds of components and subsystems that all need to be, to some extent, new technologies need to be designed and developed, but integrated and brought together to build this habitat. And so that’s really what we’re hoping to do is just get that latest thinking of where we are out there into community so they can start refining and building their own concepts.

Host: What has been the biggest challenge in creating a document like this?

Nickens: The biggest challenge I think, is finding the right level of detail to go into the document, specifically around the ground rules and assumptions. You don’t want to overtly constrain or overly constrain your assumptions, something that could stifle innovation and preclude thinking outside the box. But at the same time, you want to dial it in enough such that the assumptions and bounding conditions really align to some degree with the NASA, the government’s assumptions so we’re not off building the wrong thing. In the end, you really try to find that right balance to get a reasonable baseline. And then you iterate, iterate, iterate. And to some degree, that iteration is informed by NASA studies. And then to some degree, it’s informed by that engagement with our commercial industry and eliciting feedback from our partners.

Host: And we’re still in the very early phases of the Artemis Program. Why is it important to be doing this work now?

Nickens: Well, we’ll be reliant on technologies that either don’t currently exist or maybe are at a low Technology Readiness Level, a low TRL, or even some where we’re looking to leverage heritage ISS equipment or maybe equipment from Orion or SLS, some prior program that might need a slight modification to meet the environmental needs or performance needs that we require for Surface and Transit Habitats. And so, these technologies are necessary to close the architectures, to ensure we achieve a successful mission. If you think of technologies to address dust penetration and operating in extreme environments with shadowed periods lasting days at a time, both Surface and Transit Habitat will have those periods where we’ll be in complete darkness and need to rely on backup power systems, power storage systems.

Kind of working through those CONOPS and understanding where we have gaps in technologies, and are there technologies that exist to meet those gaps? And if not, go through those technology development cycles, which can take time. To do the design, the development, the certification of new hardware, those are generally years in the making. The earlier we can kind of get in and understand the playing field, understand what sort of capability needs we require to again, have a successful mission, the better off we are and more likely we’ll be successful in the long run.

Host: What are the next steps?

Nickens: Continuing to work the unknowns. We again, we are kind of venturing out into new environments, new concept of operations, new ways of working with systems and crew. Really decomposing those. Again, kind of going back to the prior question, understanding what sort of capability needs are required and aligning those to the technologies that are either currently available or need to be developed. Looking for opportunities to infuse new technologies as well. Maybe that thinking outside the box. Are there opportunities we can reduce mass in some way? Maybe looking at ways to drive down our sparing profile by introducing, I don’t know, some new in-space manufacturing capability. Just kind of looking at that bigger picture, refining our architectures, refining our concept of operations. Just so again, we study, study, study. Measuring twice, cut once, and can ultimately be successful in sending crew to the lunar surface in the sustained long-term presence way and then ultimately sending our first crew to Mars.

Host: Many thanks to Tiffany for joining us on the podcast. Tiffany’s bio and links to topics discussed during our conversation are available at along with a show transcript.

We’d love to hear your suggestions for future guests or topics on the podcast. If you have a suggestion, please share your idea with us on Twitter at NASA APPEL – that’s app-el – or contact us via the NASA APPEL Knowledge Services website.

As always, thanks for listening to Small Steps, Giant Leaps.