After the International Space Station: A gateway to deep space
Imagine it’s New Year’s Day, 2021. The previous year, NASA officially shuttered the International Space Station. The last astronaut has turned off the lights and landed safely.
Then what? Then WHERE?
This week, one of our senior civil servant scientists, Harley Thronson, University of Texas partner Dan Lester, and aerospace industry colleague Ted Talay published an intriguing scenario in the online journal Space Review. They explain how the United States could continue to field astronauts in space despite the recent decision to abandon the return-to-the-moon plan that reigned though most of the last decade.
The idea would be to establish a “gateway” deep-space station between Earth and the moon as a stepping stone out of low-Earth orbit for our astronauts. The coolest thing is: It could be done without the Space Shuttle, using existing launch systems such as the Delta 4, that routinely and reliably launch heavy payloads already. To save on weight, much of the station’s inhabitable space would be a thick-walled, multi-layer inflatable donut-shaped structure.
Thronson, Talay, and Lester are by no means the first or the only ones to propose an inflatable gateway station. The concept has been in development in various guises and by various people – from NASA itself to the private “space hotel” company Bigelow Aerospace – since the late 1990s. Catch up on the tech here at the Wikipedia article about the “TransHab” concept for the lunar gateway.
Thronson is Associate Director for Advanced Concepts and Planning in the Astrophysics Division at NASA’s Goddard Space Flight Center, and is involved in major initiatives to develop future large optical systems for use in space and the capabilities to build them. He started thinking about the space gateway concept in 1999, while serving on NASA’s Decade Planning Team. The group sketched out a number of next-generation concepts for human space exploration — including inflatable space habitat designs.
Thronson is still at it a decade later, and will be presenting his team’s ideas at various journals and conferences in the near future. In this week’s article, they describe their latest formulation for the gateway station. An earlier article, published in February 2010, gives additional background.
“Such a ‘Gateway’ could be the first step beyond [low-Earth orbit] in a flexible path, including returning humans to the Moon and supporting surface operations there. These habitats have also been proposed to demonstrate next-generation systems developed on the ISS that will be necessary for missions beyond the Earth-Moon system. This ‘beachhead’ for longer-range human operations at these libration points may eventually provide opportunities for other missions. For example, assembly and upgrade of complex science facilities and support for space depot systems may be carried out at these sites.”
Here are the basic bullet points for Thronson, Lester, and Talay’s gateway concept:
- Launch a fuel tanker into low-Earth orbit.
- Launch the station into orbit and refuel the Delta’s liquid-fuel second stage.
- Boost outward to L1 or L2, locations between Earth and the moon where their gravity balances out and it thus requires minimal fuel to maintain the station’s position. This would be about 60,000 kilometers (37,300 miles) from the moon.
- Send a crew of three to the station. Up to four crews could go to the station per year, each requiring two Delta 4 Heavy launches.
- The pressurized interior volume of the station would be 170 cubic meters. (The space shuttle orbiter has 71.5 cubic meters, NASA’s Skylab had 283, and the ISS has around 1,000.)
- The crew could remain for a few months at a time. This would be an opportunity to continue learning how to live and work in deep space in anticipation of future trips to near-Earth asteroids or Mars.
But here’s the really cool part. The station would be close enough to the moon to allow near-instantaneous communication with robots. Astronauts could explore the lunar surface using telepresence technology. Their view would be unhindered by bulky helmets ands suits, allowing them to experience and explore the environment in a way undreamt by the pioneering Apollo moon walkers.
That, my friends, would be Very Cool, not to mention electrifying to the public and to students.
In the end, the gateway model is a way of laying smaller, more achievable (not to mention affordable) “stepping stones” into space. And there’s still plenty to explore.
“The Apollo astronauts made only brief visits to only six places on the moon, all near the equator,” said Richard Vondrak, deputy director of the Solar System Exploration Division at NASA’s Goddard Space Flight Center in Greenbelt, Md. “Our most recent missions, such as LRO and LCROSS, are revealing new secrets of the moon and helping us to identify new places to go, such as the polar regions.”
Although the future of U.S. human space flight is somewhat uncertain right now, the dream of space exploration burns as brightly as ever.
OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.