Nasa has selected a variety of companies to work on projects to create advanced space technologies, including faster methods of propulsion.
Other projects to be worked on include improved habitats for humans, and small satellites to explore deep space.
And one of the companies in the 12 Next Space Technologies for Exploration Partnerships (NextStep) says they have an engine that could get humans to Mars in just 39 days.
The Vasimr engine - which uses plasma as a propellant - is being developed by the Ad Astra Rocket company in Texas.
Their engine shot to fame a few years ago when it was revealed that it could drastically reduce the journey time to Mars from months to weeks - although it may require a nuclear power source.
And following the successful test of a prototype in 2013, it seems Nasa is now considering it for use on a future mission to Mars.Now you're talking. Six months is too long for human physiology and psychology. To read more and view the video, click here.