Days after the US President Donald Trump promised to “unlock the mysteries of space”, Nasa has kicked off a study to assess the feasibility of adding a two-member crew to the first unmanned flight of the agency’s Space Launch System rocket and Orion spacecraft called Exploration Mission-1 .William Gerstenmaier, associate administrator of NASA’s human explorations and operation mission directorate in Washington, said they would be looking at a “big, crisp list of all the things we would physically have to change” on the vehicle in order to accommodate astronauts.