Steam-propelled spacecraft prototype can theoretically explore celestial objects "forever" [View all]
From phys.org:

Using steam to propel a spacecraft from asteroid to asteroid is now possible, thanks to a collaboration between a private space company and the University of Central Florida.
UCF planetary research scientist Phil Metzger worked with Honeybee Robotics of Pasadena, California, which developed the World Is Not Enough spacecraft prototype that extracts water from asteroids or other planetary bodies to generate steam and propel itself to its next mining target.
UCF provided the simulated asteroid material and Metzger did the computer modeling and simulation necessary before Honeybee created the prototype and tried out the idea in its facility Dec. 31. The team also partnered with Embry-Riddle Aeronautical University in Daytona Beach, Florida, to develop initial prototypes of steam-based rocket thrusters.
"It's awesome," Metzger says of the demonstration. "WINE successfully mined the soil, made rocket propellant, and launched itself on a jet of steam extracted from the simulant. We could potentially use this technology to hop on the Moon, Ceres, Europa, Titan, Pluto, the poles of Mercury, asteroidsanywhere there is water and sufficiently low gravity."
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