NASA is interested in expanding its astronauts’ options in low-Earth orbit.In a procurement filing, NASA said it seeks to buy a seat on a short-duration commercial mission to the ISS no later than 2024. That seat would be one of up to four on a dedicated commercial mission to the station lasting between 15 and 30 days. SpaceX and Boeing are both building spacecraft to serve as taxis to the space station: Boeing’s CST-100 Starliner is due to go through an uncrewed test flight to the orbital outpost next month, and SpaceX’s Crew Dragon is slated for an in-flight test of its launch abort system sometime in the next month or so.The agency has a vision of opening up the ISS to a series of companies that would bring up their own astronauts, paying essentially a rental fee to use NASA space facilities for their own work. And NASA plans to put a government astronaut on at least one of these flights to give a bit of seed money, which would help boost the efforts to bring more private astronauts into space. “The purchase of a private astronaut mission seat will directly support NASA’s low-Earth orbit commercialization goals,” NASA said in a statement, adding that this will ensure Americans will remain in orbit and will give the United States a boost in setting up more commercialization in space. (NASA officials were not available for further comment at this time due to the Thanksgiving holiday.)This week’s announcement merely serves to give notice that NASA is interested in the idea. It’s up to the organizers of future private-astronaut missions to let NASA know what they’re scheduling, and whether they’re willing to meet NASA’s requirements — for example, a four-person limit on space taxi occupancy. Right now, Boeing and SpaceX are focusing on getting their taxis up and running for the missions that are dedicated to NASA’s space station crew rotations, so it could be a year or more before they schedule the extra missions they’re entitled to offer.Nevertheless, the idea sparked a lively discussion today when it was mentioned on Twitter by NASA’s Doug Comstock, who’s acting as a liaison for commercial crew activities in low Earth orbit.Doug – I’m confused. If a “private astronaut mission” is defined by NASA (per the link in that announcement) as “a privately funded” cmrcl spflt, how can NASA buy one? If the taxpayers are paying for it, it’s not “privately funded.” https://t.co/GoO9hZ4KPz— Marcia Smith (@SpcPlcyOnline) November 27, 2019I don’t get it – isn’t NASA already paying Boeing and SpaceX to send astronauts to the ISS next year. Why is this so vaguely worded and is there something new about it?— Thomas Schumann (@Tschnn) November 27, 2019 Nowadays, maybe calling them Uber vehicles for spaceflight would be closer to the mark. If we stick with that analogy, you could say that NASA just wants to be able to get in on ordering Uber Pool rides as well as reserving an UberX for itself.