Answer: USA
Notes: NASA and the Defense Advanced Research Projects Agency (DARPA), a research arm of the US Department of Defense, announced plans to test nuclear-powered rockets that would fly humans to Mars. NASA will partner with DARPA on the Demonstration Rocket for Agile Cislunar Operations, or DRACO, programme. The mission is expected to happen by 2027. The nuclear thermal rocket will allow for a faster transit time and will also reduce the risk for astronauts.
