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Retracing the FOOTPRINTS Downloaded from http://asmedigitalcollection.asme.org/memagazineselect/article-pdf/143/3/49/6690390/me-2021-may4.pdf by guest on 24 September 2021 The landings were a water- shed moment for humanity. NASA’s new program to return to the lunar surface could well be a steppingstone to the cosmos. By Michael Abrams

he plaque left on the Sea of Tranquility by Neil Armstrong and bore a simple mes- sage: “We came in peace for all Mankind.” But the Moon Race was part of a contest between nations and ideological systems and commanded military-scale budgets from both the United TStates and the Soviet Union. Today, more than 50 years after the (and nearly 30 since the end of the USSR), NASA is engaged in a new program to send astronauts back to the lunar surface. It ought to be a cinch, as our computers, design tools, and materials are radically more advanced than they were for the first trips to the Moon. But the demands of space travel haven’t changed at all—it is still a difficult and dangerous busi- ness—and dictate the shape of more than our high-tech gadgetry. Some elements of the new program, called , will seem like carbon copies of the 1960s roadmap to the Moon. The first step—which could happen as early as this November—will be to launch an unmanned crew capsule to , dipping to within 62 miles of the surface before returning to and splashing down in the Pacific. Step two is the same as the first, but with the capsule carrying four astronauts; much like the famed mission on Christmas 1968, the astronauts will get a closeup view of the lunar surface but won’t set foot on it. The third step was intended to be different from anything that has been tried before. Unlike the Apollo missions that launched every piece of equipment all at once, the plan was for the Artemis crew to dock to an orbiting waystation. The

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An artist's rendering of a lunar designed by . The goal is to land astronauts on the Retracing the Moon by 2024. Image: Blue Origin FOOTPRINTS Downloaded from http://asmedigitalcollection.asme.org/memagazineselect/article-pdf/143/3/49/6690390/me-2021-may4.pdf by guest on 24 September 2021

0421_MEM_FEA_Moon Mission.indd 49 3/2/21 8:49 AM Technicians dressed in clean-room suits install a back shell tile panel onto the crew module. The tiles are designed to ward off the heat of re-entry. Photo: NASA Downloaded from http://asmedigitalcollection.asme.org/memagazineselect/article-pdf/143/3/49/6690390/me-2021-may4.pdf by guest on 24 September 2021

astronauts would hang out for a few orbits and then descend “The spacecraft looks similar from the outside,” said Carlos to the surface via a lander that had been prepositioned at the Garcia-Galan, Orion’s technical manager at NASA, “but from station. NASA has described the station as a an engineering perspective, it has many elements that are means to make Moon missions more sustainable, since equip- drastically different.” ment that shuttled between orbit and the surface could be By adopting the same gumdrop shape, the engineering team reused multiple times. It could even serve as a base camp for could borrow from the voluminous knowledge that NASA missions to or near-Earth asteroids. had gleaned from previous lunar visits while adding today’s That plan was revised last year: To meet a stepped-up analytical and modelling tools. “The Apollo pod people were deadline of reaching the Moon by 2024, the first landing pretty smart folks and they had solved a lot of problems,” said leapfrogged the building of the Lunar Gateway and will send Larry Price, ’s deputy program manager for everything to the surface in one fell swoop. Orion. One other, major difference between Apollo and Artemis But for all the button-downed competence we now asso- highlights the difference between the Cold War and today. ciate with the , Price said that his team discov- In the 1960s, many of NASA’s main contractors, such as ered some design decisions flirted with disaster: “We learned Grumman and North American Rockwell, built military things were a little closer to the edge than we thought before.” aircraft. For Artemis, NASA is working with space-only com- One of those edges was the . To protect the panies such as Blue Origin and SpaceX. The new race to the spacecraft on re-entry, a fiberglass honeycomb was bonded to Moon may be more leisurely than the first, but if all goes well, its skin. Apollo technicians filled each honeycomb cell with it will plant not only the American flag on the lunar surface epoxy phenol formaldehyde resin called AVCOAT and let it but also modern American capitalism. sit. The material didn’t always cure the way it was supposed to. “You couldn’t get temperature constancy through the cure Re-Engineering Re-Entry process,” Price said. Workers would have to drill out faulty In , Artemis was the twin sister of Apollo. sections and refill them. Evidence of that work is on display at It is fitting, then, that elements of the share the Smithsonian Air and Space Museum where the heat shield some DNA with its predecessor. Take the new crew capsule, on the Apollo 11 Command Module is pocked with one-inch called Orion. diameter circles.

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To get more a more predictable result, Orion engineers lightest materials, schemes to keep wiring as short as pos- switched to smaller blocks of AVCOAT-impregnated hon- sible, and jettisoning anything remotely superfluous. “I’m an eycombs, which also have the advantage of being cheaper to engineer: I want the Cadillac version in everything we do,” produce. In July 2020, NASA technicians finished gluing 180 Garcia-Galan said, “but we have to fight that urge, or you end such blocks of to the capsule’s concave surface. up working it to a point where it can never fly.” “Like every engineering solution, when you solve one For all that effort, Orion will in no way be lighter than its problem you create another,” Price said. Gaps between blocks predecessor. The Apollo command module weighed 12,251

also had to be filled. But then the behavior and performance pounds, while the crew module for Artemis comes in at Downloaded from http://asmedigitalcollection.asme.org/memagazineselect/article-pdf/143/3/49/6690390/me-2021-may4.pdf by guest on 24 September 2021 of the gap filler had to be tested and understood. “When it 21,900. Still, that is quite an achievement for a four-person erodes it changes the surface, the surface changes the local spacecraft designed to be robust enough to be reused. The aerodynamics, the local aerodynamics changes the heating, plan is to send up a crew once a year with one of four Orion which then changes the erosion,” Price added. “While we capsules while engineers and technicians refurbish the other tried to solve the problem that Apollo had in manufacturing, three. we created a challenge in engineering to show what the toler- ance was.” Lunar Logistics Re-entry isn’t the only high-energy event Orion engineers When the Lunar Modules touched down on the Moon’s have to plan for. While the Apollo missions managed to carry surface, they were met by a dusty emptiness. The plan for the its living cargo through the Van Allen belts and back with Artemis astronauts is to have resources waiting for them— minimal radiation exposure, that success was largely a matter kind of like FedExing your luggage to a hotel before you get of luck—no event sent a mission-spoiling dose their way. on the plane. But to absolutely, positively get the equipment “We have to account for solar storms,” Garcia-Galan said. to the Moon, the logistics company of choice may well be “We took a survey of solar storms over the last 50 years, took Astrobotic. The Pittsburgh-based space robotics company the worst radiation levels from the worst storm and said ‘We is scheduled to deliver 28 (including a microprint need to be able to sustain an event like that.’ ” The Orion cap- edition of Wikipedia) to the flat Lacus Mortis via its Peregrine sule has storage compartments that can be emptied and used lander later this year. The company also has a contract to land as a temporary refuge in the case a radiation event. a NASA rover in 2023. Needless to say, Orion’s engineers have scoured the vehicle “We are building a lunar delivery service,” said CEO John looking for ways to minimize weight. That means using the Thornton.

A test of the Orion's abort system in 2019 was a step toward a full lunar mission later this year. Photo: NASA

0421_MEM_FEA_Moon Mission.indd 51 3/2/21 8:49 AM BASE CAMP IN LUNAR ORBIT he Apollo Moon landings were virtually touch-and-go missions lasting as little as one day on the Tsurface. The Lunar Gateway is designed to serve as a base camp for longer expeditions. “The indi- viduals who did things like go to Mount Everest, or go to the North or South Poles—they went there very lean and very quickly,” said William “Rod” Jones, manager of the Gateway Vehicle Systems Integration Office for NASA. “They didn’t have an infrastructure to support them along the way. Now we have base Downloaded from http://asmedigitalcollection.asme.org/memagazineselect/article-pdf/143/3/49/6690390/me-2021-may4.pdf by guest on 24 September 2021 camps and stations.” The Lunar Gateway borrows much of its architecture from the International but pared down and simplified. Instead of ISS’s ungainly agglomeration of modules, the Gateway is essentially two cans: The Habitation and Logistics Outpost, where astronauts will spend their time, and a 60-kilowatt Power and Propulsion Element. The Gateway’s loopy, seven-day orbit will range out as far as 70,000 km above the power swooping in to within 3,000 km as it passes over the . “We could go lower,” Jones said, “but we picked that as a really good altitude for nominal operations. When you get close to a large body like the moon, your vehicle starts to have different heating and cooling characteristics.” Initially dreamt up when NASA’s eyes were for Mars only, the Gateway can still serve as a staging area for manned voyages farther out in the . “Gateway is an aggregation point in cislunar space,” Jones said. “It’s away from the Earth’s gravity, far enough away that we can get to it and then operate from there more freely and assemble larger vehicles.”

A view of the full Gateway docking configuration. Floating in a tin can: The Gateway is where astronauts will spend their layover before heading to the lunar surface. Image: NASA

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Astrobotic’s Peregrine lander (shown in an artist's rendering) will be able to deliver payloads to the Moon for anyone willing to buy a ride. Image: Astrobotic Downloaded from http://asmedigitalcollection.asme.org/memagazineselect/article-pdf/143/3/49/6690390/me-2021-may4.pdf by guest on 24 September 2021

Much of Astrobotic’s design for the Peregrine—foil-sided Astrobotic has a choice of from different companies chassis and spidery legs—recalls the Apollo-era Lunar that it can pick and choose from. There was no such market Modules. Even the testing regime was identical: When for Apollo’s mission planners. But for Artemis, NASA Astrobotic engineers wanted to learn how to test a lander’s went shopping for the best deals. Just as Astrobotic will be ability to stay upright on landing, they looked to 1960s NASA delivering cargo to the lunar surface and Lockheed Martin procedures. “They tilted the lander on its side, built a cart, will be building Orion, Colorado’s will and pushed it into a wall to see if it tips over,” said Pete Frye, be responsible for the power and propulsion element on the Astrobotic’s mechanical systems manager. Frye and his team Lunar Gateway, and Blue Origin is leading the development followed suit. of the lander. Even old-school aerospace contractor Northrup If the design isn’t particularly innovative, the business plan Grumman is part of the program, assembling the Habitation is. Instead of building to NASA’s order, the company sees its and Logistics Outpost portion of the Gateway. landing system as a service for hire. “For something like the “When I started at NASA there was no commercial Moon, where the goal is to go regularly—that’s the tipping concept at the time,” said William “Rod” Jones, manager of point for commercial,” Thornton said. “Flying again and again, the Gateway Vehicle Systems Integration Office for NASA. you get affordability, reliability and frequency up, so it drives “Now we are doing everything we can to leverage existing a different outcome. Instead of maximizing performance or commercial product lines in order to buy down the cost of science, you create something that is more commercial.” exploration.” Astrobotic sees itself not as a delivery company, but as a Whether Artemis ends up being a steppingstone to Mars logistics provider for organizations looking to send payloads remains to be seen. But it is almost inevitable that it will to the Moon. The company will offer power, communications be the catalyst for a new era of space commercialization— relays, visual verification of payloads deploying, rovers—even private prospecting missions, “moon-tested” products, wi-fi on the surface. “The helps push us into maybe even lunar advertising. If Apollo was “a small step for the right trajectory and then we separate pretty close to a man,” Artemis may well be a giant leap for extraterrestrial Earth and take over from there,” said Daniel Gillies, a mission capitalism. ME director at the company. Commercialization is a two-way flight path. Rather MICHAEL ABRAMS is a freelance science and technology writer based in than having to build a unique for a specific mission, Westfield, N.J.

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