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Raumfahrt - NASA’s Lunar Space Station Is a Great/Terrible Idea

10.07.2019

NASA’s orbiting Lunar Gateway is either essential for a moon landing or a boondoggle in the making

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When astronauts first landed on the moon a half century ago, they went there in a single shot: A Saturn V rocket launched the Apollo command and service module and the lunar lander, which entered into a low orbit around the moon. The lander then detached and descended to the surface. After 22 hours in the moondust, the Apollo 11 astronauts climbed into the lander’s ascent stage and returned to the command module for the trip back to Earth.

NASA’s current plan for sending astronauts back to the moon, which may happen as soon as 2024, goes a little differently. A series of commercial rockets will first launch the components of a small space station, which will self-assemble in high lunar orbit. Then another rocket will send up an unoccupied lunar lander. Finally, a giant Space Launch System (SLS) rocket will launch an Orion spacecraft (which looks a lot like an Apollo command module), with astronauts inside. Orion will dock with the space station, and some of the astronauts will transfer to the waiting lander. Finally, the astronauts will descend to the lunar surface. After their sortie on the moon, they’ll return to the orbital station, where the crew will board Orion for the trip home.

That lunar orbital space station is envisioned as a collection of modules, including habitats, an air lock, and a power and propulsion unit. NASA calls it the Gateway.

Its origins predate NASA’s current plan to return to the moon, which the agency recently rebranded as the Artemis program, and the proposed facility has grown and shrunk in response to changing policies and budgets. NASA argues that the Gateway is an essential part of its human space exploration plans. But others wonder if it’s necessary at all.

 

The Gateway’s origins can be traced back to President Barack Obama’s cancellation of NASA’s last plan to return humans to the moon (the Constellation program). In an April 2010 speech announcing a new direction for NASA’s human spaceflight efforts, Obama called on the agency to develop vehicles for deep space missions, starting with a trip to a near-Earth asteroid in 2025. However, NASA quickly determined that this goal was too ambitious, as it would require a crewed mission lasting many months. So the agency suggested an alternative: Instead of sending astronauts to an asteroid, they would bring an asteroid to the astronauts.

That idea led to the Asteroid Redirect Mission (ARM), announced in 2013. A robotic spacecraft would grab a small near-Earth asteroid—no more than 10 meters wide—and gradually shift it into a high, stable orbit around the moon, called a distant retrograde orbit, where it could be visited by astronauts on short-duration missions. But doubts about ARM’s feasibility and utility doomed the program when it came up for budget approval in the U.S. Congress.

In 2017, under the new administration of President Donald Trump, NASA pivoted again. The agency had long maintained that the space program would benefit from having a presence in cislunar space—the area between the Earth and the moon—to test technologies for future missions to Mars and beyond. NASA’s next proposal, revealed in March 2017, was a concept called the Deep Space Gateway: a collection of modules in a distant retrograde orbit around the moon. By the late 2020s, astronauts at this built-out Gateway could begin assembling a separate spacecraft, the Deep Space Transport, for long-duration missions to Mars.

That plan also fell by the wayside, though, after President Trump declared a new priority for NASA: sending astronauts back to the moon’s surface, and beginning to build a permanent presence in space.

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