Forget expensive chemical rockets, exotic fuels, and atomic spaceships. Water can transport us all to the planets. Mars, Titan, the rings of Saturn and Asteroid Belt…all are accessible just by using good old H2O.
So says Brian McConnell, a software engineer, technology entrepreneur and lead author of a study with co-author Alexander Tolley published in the prestigious Journal of the British Interplanetary Society.
The electric spaceship
The concept of the re-usable, water-fueled spaceship is both simple and eloquent. Using solar-powered electrothermal engines the craft would—in essence—be an electric spaceship.
Compared to other types of motive power for long range spacecraft, electrothermal engines are ideal. The engines can provide a continuously low thrust that will cheaply push mass through space from planet to planet. The technology opens the door for space tugs, freighters and even giant interplanetary cruise ships. McConnell calls such a ship a "spacecoach."
Researchers envision Mars as the natural first mission for a revolutionary electric spacecraft.
Living space could be created and expanded by using the technology pioneered by Nevada space manufacturer Bigelow Aerospace. The company builds inflatable space-worthy modules that have already been sent into orbit.
Water as fuel, walls, and radiation shields
Water would not only provide the fuel for the efficient electrothermal engines, but could be part of the spacecraft's body helping to absorb and block cosmic radiation infusing the space-ways.
Engineers also add that by injecting the water into bladders built into the walls, the liquid would freeze providing additional structural strength for the craft.
Interplanetary travel for pennies on the dollar
Using water, as compared to more conventional propellants, huge savings can be realized on deep space missions such as those planned for Mars.
In an interview with SPACE.com, McConnell explained the savings: "Altogether, this reduces costs by a factor of 30 times or better." What this translates into, he adds, could be a trip to the Martian moon Phobos and back for less than $1 billion—far less than the $25 billion NASA invested in the Apollo Moon program during the 1960s and 1970s. (And those dollars were worth much more 40 years ago.)
Space trains to alien worlds
The electrothermal spaceships could be linked together like a train "chugging" it's way uphill—away from the sun's gravity well—towards the outer planets. There, much more than research and exploration can be done. Resources on some moons and the asteroid belt can be the foundation of trillion dollar space industries. Mining and manufacturing in space has been a longtime dream that water-based spaceships could bring to reality.
The technology is basically off-the-shelf and can be done cheaper than any other approach. If governments don't do it, eventually private space industry will do it—or something like it.
"There's not a lot of new technology that needs to be built," McConnell said.