first_img[artist’s rendering by Robert Becker] I bet you didn’t think you’d be drinking four cups a day of a fuel that might one day take humans to Mars. Scientists say that a water powered spacecraft could complete a mission to the red planet and back for the cost of a single Space Shuttle launch today. The secret is in solar-powered electrothermal engines, a fancy name for what is essentially a steam jet. The system uses electricity to super-heat water and vent it out of an engine to provide thrust. Meanwhile, water would also be used to shield astronauts from the harmful radiation of space. After that water has been used to protect the inhabitants of the craft, it could later be shifted to the fuel tanks.This type of recycling makes the system extremely efficient to operate; quotes software engineer and technology entrepreneur Brian McConnell saying that a trip to Mars’s moon Phobos and back would cost $1 billion, or 30 times less than traditional chemical rockets. Plus, with that much water on board, crew members could possibly grow crops and have hot baths. Pretty luxurious for an extra-planetary trip.When the spaceship comes back home, it could be kept in low-earth-orbit to simplify its use in future trips. McConnell sees the vessels being used for several decades before they need to be replaced, similar to the Space Shuttle’s long history of service. With fresh food, hot baths and a low price tag, the water-powered rocket is a pretty attractive vision of the future. And an interesting point of discussion over a nice cool glass of rocket-fuel.[via]last_img read more