Imagine going to the planet Mars on a mission lasting two-and-a-half years.
That's what a crew of astronauts could be doing in the year 2031 under plans just unveiled by the American space organisation, Nasa.
It would take the astronauts up to seven months to reach the red planet in their spacecraft, then they'd spend more than a year living there.
Nasa is planning lots of hi-tech equipment for the trip because the crew would need to look after themselves.
They would have to be able to grow their own food, treat their own illnesses and fix their space stuff when it goes wrong.
In 2004, it was announced that America intended to send humans back to the Moon by 2020, with a Mars mission planned for an unnamed date.
The surface of Mars
Nasa's latest announcement reveals much more.
It says the astronauts could grow their own fruit and veg, and that - once on Mars - they will power their base using nuclear energy.
It's thought the hi-tech gear needed to do this could be tested on the Moon before the Mars mission has lift-off.