In the US, Donald Trump Administration has directed NASA to study whether it is feasible to fly astronauts on the debut flight of the agency's heavy-lift rocket, a mission currently unmanned and targeted to launch in late 2018.<br/><br/>Officials said the study marks the Republican president's first step in shaping a vision for the National Aeronautics and Space Administration. Under President Barack Obama, the US space agency was working on the heavy-lift Space Launch System rocket and Orion deep-space capsule with the aim of sending astronauts to rendezvous with an asteroid in the mid-2020s, followed by a human expedition to Mars in the 2030s.<br/><br/>The request for the study from the new administration tweaks that plan by exploring whether to add a crew to an earlier test flight and perhaps setting the stage for a human return to the moon.