Axiom Space Celebrates National Moon Day, Hosts Reddit AMA on AxEMU Spacesuit

Axiom Space marked the anniversary of the Apollo 11 Moon landing by hosting a Reddit "Ask Me Anything" forum on r/IAmA dedicated to the Axiom Extravehicular Mobility Unit (AxEMU) — the spacesuit that will enable astronauts to return to the lunar surface for the first time in more than 50 years.

Answering questions were Dan Burbank, Axiom Space's Chief Technology Officer of Human Spaceflight and a former NASA astronaut, who logged 188 days in space and more than seven hours of spacewalk time across missions including STS-106, STS-115, and ISS Expeditions 29/30; and Tammy Radford, the company's Extravehicular Activity Services (xEVAS) Program Manager, who oversees the AxEMU's design, certification, and deployment and previously led development of the suit's Portable Life Support System (PLSS). Between them, the pair spent the session engaging with Redditors about the engineering behind the suit that will support astronauts on Artemis IV.

Here is a look at some of the questions they covered over the hour-and-a-half session:

Differences From Apollo-era Suits
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Q: From afar, the suit looks remarkably similar to the old one (no offense please). What makes this suit different from it? What makes it better?

Tammy Radford: "The AxEMU suit may look similar, but it has a lot more capability. It can support longer duration space walks, up to 8 hours. This is accomplished with more oxygen and providing in-suit nutrition to the crew, something that wasn't included in the past. It will protect the crew member in harsher environments like the permanently shadowed regions of moon. The boot sole provides the insulation needed to accommodate –250°F temperatures. And it will provide more mobility so the crew members can complete all the mission's tasks. The easier it is for them to work in the suit, the more geological science they will be able to accomplish during the mission."

Anthropomorphic Sizing
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Q: Thank you for your part in advancing us to the stars. Are the suits going to be custom fit for every person? Or are they going to be small, medium, large, xl...?

Dan Burbank: The “macro sizing” is based off the spacesuit “HUT” or hard upper torso and those are similar to S, M, L, XL.  We want to ensure the AxEMU fits the broadest range of crewmember sizes possible.  With several base HUT sizes, we’ll be able to accommodate 1st to 99th percentile crewmember sizes, which means that effectively anyone can be “Go for EVA”.

Manufacturing
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Q: SpaceX designed their EVA suit architecture around mass manufacturability for large crews. What is Axiom's long-term production and fleet strategy for the AxEMU — are you scaling production for dozens of units, or targeting a small fleet of customized suits servicing Artemis and commercial station missions?

Tammy Radford: "Axiom Space is currently on contract to build two qualification suits (one focused on mobility and the other focused on life support performance), one flight suit for an ISS Demonstration, two flight suits for the Artemis 4 crew, a suit for joint testing with the HLS teams, 2 spares, and we are anxiously waiting for NASA to turn on the Artemis 5 flight suits. Building space suits is a low quantity endeavor until the commercial space economy takes off. We will support Artemis and commercial stations with our fleet and plan to continue to grow our fleet as the need arises."

Lunar Environment
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Q: Did NASA lose all the other spacesuits? But seriously, what are some of the unexpected challenges or issues you've faced in the process?

Dan Burbank: "One very challenging aspect of the Moon as an EVA destination is the extremely cold temperatures at the lunar south pole. The PSRs (permanently shadowed regions) are on the one hand incredibly valuable and are extremely challenging on the other hand. The PSR surface temps are about –40 Kelvin and that's cold enough to preserve 100s of millions of tons of water from billions of years of cometary impacts and that water is invaluable as water, as oxygen and even as rocket fuel. Those temperatures make the suit materials and thermal control system very challenging to design and have been a major focus of the AxEMU development effort."

Looking Ahead

The AxEMU is on track to take its first steps on the Moon in 2028 as part of Artemis IV, representing both a continuation of five decades of spacesuit lessons learned and a fundamentally new approach to protecting and enabling astronauts on the lunar surface.

Axiom Space thanks everyone on r/IAmA who joined the conversation and looks forward to sharing more updates as the AxEMU moves toward its next milestones on the journey back to the Moon.

The complete AMA, from suit mobility to broadcast capability, is available on r/IAmA here. To stay up to date on future events, be sure to follow us on social media.

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