ARS Technica by Eric Berger - 7/31/2019
"The civil servants at Marshall and at Glenn are very talented in this area."On Tuesday afternoon, NASA announced 19 new partnerships with 10 US companies to help bring more cutting-edge technologies closer to production use in spaceflight. There were a lot of useful engineering ideas here, such as precision landing systems and robotic plant farms, but perhaps the most intriguing one involved the rocket company SpaceX and two of NASA's field centers—the Glenn Research Center in Ohio and the Marshall Space Flight Center in Alabama.
"SpaceX will work with Glenn and Marshall to advance technology needed to transfer propellant in orbit, an important step in the development of the company’s Starship space vehicle," the NASA news release states. This is a significant announcement for reasons both technical and political.
For its part, SpaceX welcomed the opportunity to help advance NASA's Artemis Program, which NASA hopes will send humans to the Moon by 2024 (and, later on, to Mars). “We believe SpaceX’s fleet of advanced rockets and spacecraft, including Falcon Heavy and Starship, are integral to accelerating NASA’s lunar and Mars plans," a company spokesperson told Ars.
Technical
One of SpaceX's principal engineers behind the Starship project, Paul Wooster, has identified orbital refueling as one of most difficult technology challenges the company will have to overcome in order to realize its Mars ambitions.
Under some scenarios by which the company aims to send humans to Mars, a Super Heavy rocket would launch a Mars-bound Starship to low-Earth orbit. At that point, the spacecraft would need to top its fuel tanks back up in order to get its payload all the way to the Red Planet. It's estimated that five Starship launches' worth of fuel (as payload) would be required to refuel a single Mars-bound Starship in low-Earth orbit, and this would involve the transfer of hundreds of tons of methane and liquid oxygen.
More:
https://arstechnica.com/science/2019/07/nasa-agrees-to-work-with-spacex-on-orbital-refueling-technology/
