Planning For A Coninuous Human Presence In LEO

Haven-2 In its final form, Haven-2 will feature eight modules attached to a larger core module. (credit: Vast) Planning for the future of continuous human presence in LEO by Jeff Foust Monday, October 28, 2024 Bookmark and Share It is not clear that the sprawling exhibit hall at the International Astronautical Congress (IAC) earlier this month in Milan had a center, with exhibitors split into two halls with a tent-like temporary structure connecting the two. But, certainly, one the exhibits at the heart of the hall, based on the activity there, was commercial space station company Vast. The company’s large booth features VR experiences of its proposed station and a model of its “patent-pending signature sleep system” that it says will allow for a better night’s sleep for future astronauts on its station. Vast used IAC to highlight the final design of Haven-1, the single-module space station it plans to launch in the second half of next year on a Falcon 9. It will be visited by up to four four-person crews for brief stays, carrying out research and other work while giving Vast experience for future stations. “We operate under the assumption that we are all-in on winning CLD,” Haot said. More importantly, the company used the conference to unveil its plans for Haven-2, the company’s next station and the one it plans to offer to NASA as a commercial successor to the International Space Station. That facility will be built in phases over several years, one module at a time. “Our competitors have put out designs of what they plan to do, and Vast has only shown Haven-1,” Max Haot, CEO of Vast, said in an interview. That’s a reference to space station proposals from Axiom Space, Starlab Space, and the Orbital Reef effort of Blue Origin, Sierra Space and others that, unlike Vast, has support from NASA’s Commercial LEO Destinations (CLD) program. Vast does not have a CLD award—the company started operations only after the “Phase One” awards in late 2021—but it has been working hard to catch up, fueled by investment from company founder Jed McCaleb, a cryptocurrency billionaire. The release of the Haven-2 design at IAC was the company’s effort to show prospective customers, including NASA, what its plans are for the station. Haven-2 would start with a single module launched on a Falcon Heavy in 2028. The module is a stretched version of Haven-1, five meters longer and with twice the usable volume. That module alone could support some crew-tended missions. Vast, though, would follow that initial module with three more identical ones, launching about six months apart through 2030. The four would dock with each other in a line to form the first phase of Haven-2. Each module would be functionally identical but could be outfitted differently inside to serve different needs, such as lab space versus habitation. The second phase would begin around 2030 with the launch of a core module with a seven-meter diameter on SpaceX’s Starship. The four modules of the phase-one station would then undock from one another and attach themselves to four docking ports on that core module, which also has additional docking and berthing ports for visiting vehicles, a robotic arm, and an airlock for spacewalks. Vast will then launch four more modules similar to the first four, although some will have unique features: one will have an external payload rack and airlock similar to that on the Kibo module on the ISS, while another will have a cupola 3.8 meters across, much larger that the ISS cupola. The company envisions the station reaching that final version in 2032. “By that time, it’s more capable than the ISS,” Haot said, “and we hope and expect more capable than anything China and Russia have on orbit at that time.” Vast, since the company’s founding, has outlined ambitious plans for large space stations, including those that would rotate to provide artificial gravity. However, the company is making clear with the rollout of the Haven-2 design that it is focused on winning the next phase of the CLD competition, securing NASA funding for certifying the station for NASA astronauts and for providing space station services to NASA. “We operate under the assumption that we are all-in on winning CLD,” Haot said when asked if the company had a backup plan should NASA not select Haven-2 for the next phase of the program. He said Vast sees NASA as the anchor customer, but not the only one, for Haven-2. With NASA, along with other companies and space agencies, “we can be a profitable company.” Because of that, Vast is deferring to NASA on some aspects of the station’s design. The orbit, Haot said, will depend on what NASA defines in the next phase of the CLD program. While Vast has a close relationship with SpaceX for Haven-1, including requiring the use of Crew Dragon’s life support system to enable crewed operations, Haot said the company will be open to other vehicles, like Starliner. Haven-2 also will not have an artificial gravity capability despite Vast’s stated interest in it. “Haven-2 is really designed for NASA as the anchor customer, and NASA’s requirement is the opposite of artificial gravity. It’s a microgravity laboratory in space,” he said. Haven-2 At the end of one phase of Haven-2’s development, it will have four largely identical modules attached in a line. (credit: Vast) NASA’s microgravity strategy and redefining “continuous presence” With Vast’s unveiling of the Haven-2 design, most of the likely competitors for the next phase of the CLD program have shown what they plan to offer to NASA as commercial successors to the ISS. Axiom Space is developing a series of modules it will initially install on the ISS before detaching them to create a commercial station. Starlab Space is planning a large single-module station launching on Starship. Orbital Reef is pursuing a modular station, although one of its partners, Sierra Space, has discussed launching one of its inflatable modules as a standalone pathfinder station first. “Continuous human presence: what does that mean?” Melroy asked. “Is it a continuous heartbeat or a continuous capability?” Those companies are now looking to NASA to provide details on its specific requirements for commercial stations. A formal request for proposals is slated for release next year—preceded by a draft for industry comment—with phase two awards planned for 2026, said Robyn Gatens, ISS director and acting commercial spaceflight director at NASA headquarters, during a briefing at the IAC. NASA has, in the meantime, been working to define exactly what it wants to do on such commercial stations. The agency released in August a draft of a LEO Microgravity Strategy modeled on its Moon to Mars strategy. The strategy outlines goals and objectives, from research to exploration planning to workforce development. “It’s an effort to define what it is we want to accomplish in the next generation of human presence in low Earth orbit,” NASA deputy administrator Pam Melroy said in a talk at IAC. NASA requested comments on the strategy and received more than 1,800 responses, Melroy said. That will lead to a final version of the strategy by the end of the year, and feed into the requirements NASA plans to include in the request for proposal for the next phase of the CLD program. NASA has emphasized, throughout the effort to help develop commercial replacements for the ISS, its desire to maintain a continuous human presence in LEO. That includes an overlap between the first commercial station and the retirement of the ISS, currently proposed for 2030, to enable a smooth transition. But Melroy, at IAC, suggested that NASA was rethinking the concept of “continuous human presence” or, at least, how NASA defines it. “Continuous human presence: what does that mean?” she said in her talk about the LEO microgravity strategy at IAC. “Is it a continuous heartbeat or a continuous capability? While we originally hoped that this would just emerge from this process, we’re still having conversations about that.” The idea of “continuous heartbeat,” she explained at a later briefing, was what most people thought of regarding continuous human presence: having people in space without a break, maintaining the current 24-year record of humans on the ISS. Doing so, she said, had benefits for both maintaining scientific research and national prestige. “There’s a national posture element to it, to not have humans on orbit after what would be nearly 30 years of continuous presence” when the ISS is retired in 2030. The alternative, “continuous capability,” would be to maintain the ability to have humans in orbit but not continuously. That would instead involve shorter missions with gaps, which she suggested would be an interim solution while companies developed the capabilities for permanently crewed stations. “We know that our partners are going to evolve,” she said. “We didn’t build the space station overnight and they won’t either, so they will have limited capabilities to start with.” Gatens offered a similar assessment at the briefing. “Do we need continuous heartbeat to achieve our objectives, or could we live with something like a crew-tended capability and maybe evolve to a continuous heartbeat?” she asked. “Do we need continuous heartbeat to achieve our objectives, or could we live with something like a crew-tended capability and maybe evolve to a continuous heartbeat?” Gatens asked. Melroy suggested she was leaning towards the more traditional “continuous heartbeat” approach since it was also needed to support providers of commercial crew and cargo providers, who might struggle if flights to crew-tended stations are less frequent than to stations that are permanently crewed. “It doesn’t matter if you have a space station if there’s no way to get there,” she noted. What was less clear from the discussion, though, is what would happen if NASA adopted the continuous capability option, at least temporarily. What would it mean for the business cases of commercial space stations, as well as when and how—or even if—would NASA shift to the continuous heartbeat approach. Answering those questions will be important not just for NASA’s strategy but also for the business plans of the companies that are relying on NASA to be an anchor customer for the commercial stations they seek to develop. Jeff Foust (jeff@thespacereview.com) is the editor and publisher of The Space Review, and a senior staff writer with SpaceNews. He also operates the Spacetoday.net web site. Views and opinions expressed in this article are those of the author alone.