United States President Barack Obama says it should be possible to send astronauts to orbit the planet Mars by the mid-2030s and return them safely to Earth.
In a speech at the Kennedy Space Centre, Mr Obama promised an extra $US6 billion for space exploration.
He said the money will allow for ambitious new plans, including further investigations into Mars.
Mr Obama announced in February that a plan to return Americans to the moon by 2020 would not proceed.