NASA’s steampunk solution to space travel
If there's one thing holding us back from exploring space, it's fuel. It's bulky. It's heavy. And probes must carry their own supply. When that runs out, their lights go out. But what if every asteroid represented a potential pit-stop?
The issue of powering craft through space won't go away.
Solar panels can provide all the electricity a space probe needs. But, if it wants to move, it must also have a propellant.
We have ultra-efficient ion engines. But even these need to carry stocks of expensive Xenon gas.
We're experimenting with light sails. But we've a way to go to effectively tack against the solar winds.
Now NASA has taken a step back.
Back to the age of steam.
A flurry of space probes scattered through the solar system have taught us one thing: water is surprisingly common.
At least in the form of ice.
Wherever there is a deep crater, or crack, there's likely a frozen deposit.
And this presents an exciting opportunity: readily available fuel.
A new prototype has been funded by NASA to test the concept of refuellable, steam-powered spacecraft.
The University of Central Florida and Honeybee Robotics dubbed it the World Is Not Enough (WINE) experiment.
It's designed to fly to an asteroid, do its research - and mine for water at the same time.
Once topped up, it can move on to its next objective.
That's something our space explorers have been dreaming of for decades.
And the technology has just taken its first step.
On December 31, a microwave oven sized prototype 'hopper' was put in a vacuum tank.
In the tank was a layer of simulated asteroid soil.
The spacecraft then gathered its own fuel. Then it 'took off'.
"WINE successfully mined the soil, made rocket propellant and launched itself on a jet of steam extracted from the simulant," UCF planetary scientist Phil Metzger says. "We could potentially use this technology to hop on the Moon, Ceres, Europa, Titan, Pluto, the poles of Mercury, asteroids - anywhere there is water and sufficiently low gravity."
And it doesn't even need soil. It can land on a block of ice.
The experimental Spider Water Extraction System can "drill into tough icy and mineral composites that can be as hard as concrete," its manufacturer, Honeybee, says in a statement.
"Using local resources means missions can start with lower supplies, or extend their missions far beyond what is possible with materials on-board."
BACK TO THE FUTURE
The idea is not a magic bullet.
Water is not a terribly efficient propellant.
So it's only applicable for spacecraft bouncing around between low gravity locations.
But that's no different to modern ion-engine powered probes such as Dawn, which recently explored the dwarf planets Vesta and Ceres. It ran out of its expensive propellant last year.
Water, however, is readily available. And cheap.
And it offers the same kind of low-thrust, sustained propulsion as Dawn's ion engine. Just with the added option of repeatedly refuelling itself.
"WINE was designed to never run out of propellant so exploration will be less expensive," Metzger says. "It also allows us to explore in a shorter amount of time, since we don't have to wait for years as a new spacecraft travels from Earth each time."
Steam-powered probes can use solar powers to heat the ice into steam, or small - hot - radioactive decay units. Or both.
This means such craft can potentially explore the outer reaches of the Solar System, such as Pluto.
"The WINE-like spacecrafts have the potential to change how we explore the universe," Honeybee Robotocs vice president Kris Zacny says.