Nasa will allow private citizens to stay at the International Space Station (ISS) for month-long getaways at a cost of about US$35,000 per night, the US space agency said on Friday. The shift reverses a long-standing prohibition against tourists and private interests at the orbiting research lab, and reflects a broader push to expand commercial activities at the ISS and in space more generally. It paves the way for private citizens to travel to the ISS aboard rocket-and-capsule launch systems being developed by Boeing and Elon Musk’s SpaceX. The two companies are set to ferry astronauts to the ISS from US soil for the first time in nearly a decade. Nasa will allow up to two private trips to the station per year, each lasting up to 30 days, Nasa said. The first mission could be as early as 2020. But the ride won’t be cheap. Nasa wanted to use China’s spacecraft to plan a new American moon mission Nasa estimated the cost of a flight would be around US$50 million per seat. In addition, Nasa will charge visitors for food, storage and communication once at the station. “If you look at the pricing and you add it up, back of a napkin, it would be roughly US$35,000 a night, per astronaut,” Nasa’s chief financial officer, Jeff DeWit, told a news conference in New York. “But it won’t come with any Hilton or Marriott points,” DeWit joked. Nasa’s Russian counterpart, Roscosmos, has already allowed a number of private citizens at the station.