Steam-Powered Spacecraft Could Explore the Asteroid Belt Forever, Refueling Itself in Space

The era of renewed space exploration has led to some rather ambitious proposals. While many have been on the books for decades, it has only been in recent years that some of these plans have become technologically feasible. A good example is asteroid mining, where robotic spacecraft would travel to Near-Earth Asteroids and the Main Asteroid Belt to harvest minerals and other resources.

At the moment, one of the main challenges is how these craft would be able to get around and refuel once they are in space. To address this, the New York-based company Honeybee Robotics has teemed up with the University of Central Florida (UFC) to develop a steam-powered robotic spacecraft. The company recently released a demonstration video that shows their prototype World is Not Enough (WINE) “steam hopper” in action.

Founded in 1983, Honeybee Robotics has a long history of developing technologies for space exploration. In that time, they have fulfilled over 300 contracts for NASA, which has included tools used by the Spirit, Opportunity and Curiosity rovers and the Phoenix lander. Addressing the prospect of asteroid mining, the company teamed up with UCF scientist Dr. Phil Metzger to develop a robotic spacecraft for the sake of commercial mining.

In addition to being an associate with the UCF’s Planetary Science Group (PSG), Dr. Metzger has a long history of working with NASA. In fact, Metzger co-founded the Swamp Works at NASA’s Kennedy Space Center, which is modeled on Lockheed Martin’s Skunk Works and designed to implement innovation strategies adapted from Silicon Valley.

At PSG, Metzger continues to develop what he refers to as “Economic Planetary Science”, which is focused on developing technologies for in-situ resource utilization (ISRU) – ranging from mining and manufacturing to construction. Much like the development of reusable spacecraft, ISRU aims to make space exploration more cost-effective by relying on locally-harvested resources.

That is the principle behind the WINE spacecraft, which would harvest water ice from asteroids or planetary regolith. This ice would then be captured in a cold trap and heated to create steam for propulsion. Electrical power would be provided by solar panels, or possibly a light-weight radioscoptic heater unit.

These choices of power supply would allow for mission flexibility by giving the robotic spacecraft the ability to work in different environments. For instance, if the hopper were working in low gravity environments closer to home, solar panels would suffice. If it were operating in high-gravity environments and/or locations far from the sun, a nuclear battery would be the method of choice.

A video of the prototype’s first demonstration was recently posted on twitter by Kris Zacny, Vice President of Honeybee Robotics. As Metzger described the demonstration in a recent UCF press release:

“It’s awesome. 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, asteroids – anywhere there is water and sufficiently low gravity.”

The prototype steam hopper was created by Honeybee in collaboration with Embry-Riddle Aeronautical University, which helped develop the initial steam-based rocket thrusters. UCF provided the simulated asteroid material, while Metzger created the computer models and simulations needed to prove the concept (a process that took three years).

The hopper would leverage key pieces of technology like the Mobile In-Situ Water Extractor (MISWE), a spiral fluted coring tube that was developed by Honeybee for NASA missions to the Moon, Mars, and beyond. For the WINE spacecraft, this extractor is combined with a 3D-printed cold gas thruster and a tank that were specifically designed to fit inside a CubeSat.

The 11-second video posted to twitter shows the prototype firing its engine and levitating at the company’s test facility on Dec. 31st. This demonstration came at the conclusion of a Phase 2 grant awarded by NASA’s Small Business Innovation Research and Small Business Technology Transfer (SBIR/SBTT) programs – which was awarded in 2016 and lasted for two years.

“The project has been a collaborative effort between NASA, academia and industry; and it has been a tremendous success,” said Kris Zacny in a company press statement. “The WINE-like spacecrafts have the potential to change how we explore the universe.”

The implications of this technology go far beyond asteroid mining. At present, interplanetary missions are forced to conclude once the spacecraft runs out of propellant. But as Metzger explained, the development of this type of spacecraft (which can mine and process its own fuel), would significantly extend the lives of interplanetary missions:

“Each time we lose our tremendous investment in time and money that we spent building and sending the spacecraft to its target. WINE was designed to never run out of propellant so exploration will be less expensive. 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.”

Given the rate at which commercial aerospace (aka. NewSpace) is progressing, and the fact that asteroid prospecting will be commencing very soon, it could be just a decade or even a few years before mining craft like WINE are being sent to the nearest asteroids. And with multiple agencies looking to conduct lunar and Martian exploration missions, steam hopper spacecraft could find themselves traveling all across the Solar System.

Given the potential payoff, there is likely to be no shortage of industries looking to get in on this burgeoning industry. And if the technology and methodology can be worked out, humanity could be looking at the Gold Rush to end all gold rushes. Not to mention iron, nickel, cobalt, manganese, molybdenum, aluminum, titanium, water and a whole lot of other resources!

The company has since released a full-length video that showcases the WINE concept and the technology demonstration. Check it out below:

Further Reading: UCF, The Space Resource, Honeybee Robotics