Behind the Technology Fueling Space Exploration and Resource Extraction

The key to fueling the burgeoning private space exploration industry? Water. Read how a Seattle-based startup plans to mine asteroids for water, or more specifically, hydrogen and oxygen — the makings of rocket fuel.

By Kathryn Nave, Contributor

Most asteroids are plain old lumps of rock and dirt. A few are composed of metals such as nickel, iron, or even platinum. But the really valuable ones—the ones that fill Planetary Resources CEO Chris Lewicki with enthusiasm—are the carbonaceous variety. Though these asteroids are predominantly composed of carbon, thanks to their porous structure, they are also rich reservoirs of space water.

“Water is the key resource for large scale development in space,” Lewicki said. “Though on earth we think of it as just a liquid that we drink or use for cleaning, in space it is hydrogen and oxygen—and hydrogen and oxygen are rocket fuel.”

The Seattle-based startup’s plan is to locate carbonaceous asteroids close enough to Earth’s orbit, mine them for water, and sell that material to the burgeoning private space industry. Water, or rather its components, will then provide fuel for rocket engines and oxygen for astronauts up in space.

Here’s how mining asteroids could transform the scope of human space exploration as we know it.

“Water is the key resource for large scale development in space. Though on earth we think of it as just a liquid that we drink or use for cleaning, in space it is hydrogen and oxygen—and hydrogen and oxygen are rocket fuel.”
— Chris Lewicki, CEO, Planetary Resources

Rethinking a Precious Resource

When an astronaut heads to the International Space Station, their home country’s space agency must equip them with everything they will need for the next several months, including water. The result is one heavy rocket ship on launch day.

Space X’s Falcon Heavy rocket, for example, weighs 12,800 pounds, or 64 tons. Even though it’s the most efficient and high capacity rocket in history, to get it to low Earth orbit—where the International Space Station resides—it costs $90 million per launch. (That breaks down to $1.5 million per ton.)

The reason for this exorbitant cost has to do with the amount of energy needed to fight the earth’s gravity when launching into space. For every ton of mass transported to what’s known as low earth orbit, it requires an additional ten tons of fuel to get it there. (And rocket fuel is expensive.)

“It’s like trying to drive across the country with a small tank of gas and carrying all the gas you’d need to refuel inside the car with you,” Lewicki explained.

The advantage of tapping asteroids for a vital resource like water is that, their relatively small size means they lack significant atmospheric pull. In other words, it requires almost no energy—fuel—to land or take off. The cost of extracting water in space, then, becomes far cheaper than launching it from earth, where each ton has to fight a tremendous amount of gravity.

Lewicki believes this potential water source will not only appeal to national space agencies for its cost savings, but also to private space tourism operators like Space X and Virgin Galactic. While water is a life-sustaining resource for astronauts, when converted into liquid hydrogen and oxygen, it can also be used to re-fuel the spacecraft itself. This alone, Lewicki explained, could massively expand the range of human space travel.

“Once you get into low earth orbit, you’re halfway to anywhere in the solar system,” Lewicki said. “When you think about that in terms of linear distance, it doesn’t make any sense. But in space travel we don’t care about distance, we care about energy.”

Funding the Mission

Planetary Resources’ backers range from Google founder Larry Page and Virgin CEO Richard Branson to the government of Luxembourg, which enacted a package of space mining legislation to support the private space industry. (The year before, the tiny European nation set aside roughly $245 million USD to invest in space mining.)

In 2015, the U.S. government passed its own space mining legislation, the U.S. Commercial Space Launch Competitiveness Act, which provided a legal foundation for the commercial use of extraterrestrial resources.

And Planetary Resources hopes to be one of those lucky companies.

In January, the company successfully launched its second prototype satellite, the first with sensor technology on board. The Arkyd-6, a printer-sized nanosatellite, is equipped with a powerful mid-wavelength infrared sensor, which allows for extremely precise long-range thermal imaging. While initially developed for aerial drone surveys, these sensors also work well to capture distant space objects.

According to Lewicki, the technology can assess potential water content in near earth asteroid candidates, helping identify potential targets for exploration and water extraction.

Artist rendering of the Arkyd-6. Image credit: Planetary Resources

Future satellites will also include hyper-spectral imaging sensors —capable of analyzing light from 40 points from across the electromagnetic spectrum, from low frequency radio waves, through the full spectrum of visible light, to high frequency gamma wave radiation. This information can be used to assess what else the rock has inside.

“By analyzing the particular spectral fingerprint of reflected light, we can get a good idea of what [the object] is made of,” explained Lewicki. In other words, in addition to analyzing water content, these sensors can identify the presence of rare metals, such as platinum, gold, or palladium.

(Closer to home, Arkyd-6 sensors can provide intelligence about the location of valuable resources for the mining industry, or crop and soil conditions for agriculture efforts.)

Within the next couple of years, Planetary Resources plans to have identified their first asteroid targets for further exploration, and in 2020, it is set to launch a number of small spacecrafts with small, low-energy propulsion systems to journey to these target asteroids and collect sample materials.

Building in Space

While fueling long-distance spacecrafts is Planetary Resource’s first goal, the next step is to provide the materials to build these rockets. And by tapping into metallic asteroids, this might just be plausible.

“At the moment, most of the engineering and design that goes into a spacecraft is for the first nine minutes of its life—it’s got to fit into a tiny capsule in the top of the launch vehicle and survive the vibration and acceleration of the rocket ride,” Lewicki explained. “If can use these [metallic] materials to 3D-print components to assemble the spacecraft in space, I don’t have to care about any of that.”

(Other, earthly uses for the metallic asteroids include iron for steel-making and platinum for the electronics industry.)

With the ability to refuel engines, provide water, and build the spacecrafts in space, Planetary Resources might be primed to do more than just reduce the cost for space exploration companies to send a few wealthy tourists off of this planet. According to Lewicki, the company could help nurture the ambitions of space colonization evangelists, such as Elon Musk.

“Asteroids are the most accessible resources to allow us to stretch our legs, to set up infrastructure on the way to Mars, and then on Mars itself,” Lewicki said. “This is how colonization takes off.”