How 3-D Printing Is Going Out of This World

How 3-D Printing Is Going Out of This World

Researchers explore ways to build objects in space; lunar dust as ink

By Robert Lee Hotz in the Wall Street Journal

Dutch television producers chose 100 contestants in February to vie for a one-way trip to Mars. If all goes as advertised, winners might be landing there sometime in 2027. They’ll quickly need permanent shelter. The nearest Home Depot will be 140 million miles away. The only readily available construction material on Mars is sand.

That might be all they need if a plan by Niki Werkheiser and her engineering team at NASA’s Marshall Space Flight Center works out. They are experimenting with a 3-D printer that would make bricks suitable for airtight buildings and radiation-proof shelters using the grit that blows across Mars’s red surface.

In Huntsville, Ala., Ms. Werkheiser, NASA’s 3-D print project manager, is starting to print curved walls and other structures using imitation Martian sand as an ink. Engineers at the European Space Agency are exploring ways to use lunar dust as an ink to print out an entire moon base. London-based architects Foster + Partners have designed a printable lunar colony.

And if astronauts ever do attempt to reach Mars, they may survive the journey by eating pizza made with a 3-D-printed food system for long duration space missions, now under development in Texas.

Industrial engineers and designers on Earth have been printing in three dimensions for a decade or more, using modified computer inkjet printers. Instead of colored inks, these printers extrude plastic, alloys or ceramic composites, mixed with a hardening agent, to build up complex shapes one paper-thin layer at a time. Aerospace engineers are adapting printers to make rocket engine parts and other industrial components.

Now 3-D printing is out of this world.

“You need this type of technology if you are going to settle other worlds,” said Aaron Kemmer, CEO of Mountain View, Calif.-based Made In Space Inc., which is developing space-based printing technology.

Mr. Kemmer and his associates are testing an advanced microgravity printer that can print parts made of ceramics, composite materials and high-temperature polymer plastics. They are experimenting with a material called regolith, which is a pulverized volcanic grit used as a stand-in for genuine moon dust.

“It was pretty messy at first,” said Michael Snyder, the company’s lead engineer. “It is like printing with powdered sugar.”

They have had some real off-world successes.

Aboard the international space station last December, NASA astronaut Barry Wilmore printed out a ratchet wrench—the first tool to be printed in orbit.

An engineer at Made In Space designed the wrench on Earth, converted the blueprint into computer code, and then emailed it to U.S. Navy Capt. Wilmore in orbit. There, the astronaut printed the tool on the company’s experimental 3-D microgravity printer in three hours, building it up in layers each about 7 millimeters thick from an ink composed of a heated commercial plastic.

That material doesn’t float away as it builds up in the printing tray. NASA engineers aren’t sure yet, though, whether the laminated layers bond properly as they cool in the absence of gravity.

Typically, an astronaut might have to wait a year or more for a new tool to be shipped into orbit. In all, Capt. Wilmore printed 25 experimental parts and shipped them back to Earth. Later this month, NASA engineers expect to start inspecting them for flaws.

“The 3-D printer on the space station is a first step,” Ms. Werkheiser said. “It opens our mind to possibilities. There are things we think we can make in zero gravity that you can’t make on Earth.”

In theory, advanced printers one day could be landed long before human colonists to lay down landing pads, roads and shelters. They might even print out working replicas of themselves or swarms of self-assembling construction robots. A self-replicating 3-D printer that would spawn new, improved versions of itself is in development at the University of Bath in the U.K.

At the European Space Agency, engineers are working out ways to make an entire Moon colony using current 3-D printing technology.

On a recent trial run, they used a 3-D stereo-lithography printing process developed by Monolite UK Ltd. that can print objects up to 19 feet long on each side. They mixed simulated lunar dust with magnesium oxide and printed out stone-like building blocks weighing one-and-a-half tons each.

 “It would be economically impossible to send all these bricks from Earth to the Moon,” said space materials engineer Laurent Pambaguian in Noordwijk, Netherlands, who is in charge of the ESA project. “There would be no other way but to send a 3-D printer up.”

Later this year, the European Space Agency plans to launch its own experimental 3-D microgravity printer, developed by the Italian Space Agency, to the space station. NASA, Made In Space and the European agency each are seeking to use yet another option for interplanetary ink: trash. They are developing recycling systems that would allow plastic tools, food wrappers, packing materials and other space-station waste to be melted down and reprinted into other useful objects as needed.

That could reduce the need to launch raw materials into orbit at a cost of thousands of dollars per pound, said Wolfgang Veith, head of ESA’s product assurance and safety department. Last year, astronauts tossed 3,300 pounds of cargo pallets, equipment, food, mini-satellites and clothing overboard, to burn up in the atmosphere.

A 3-D printer may one day be in the carry-on luggage of every savvy solar system traveler, but the technology is still too experimental for the privately funded Mars One expedition, said Bas Lansdorp, CEO of the Mars One organization.

In the meantime, the Mars One producers will hew to the tried and true. As envisioned, the reality show contestants will live in inflatable airtight huts, ferried by rockets to Mars and erected by a robot rover before they arrive. If colonists need more protection, they can shovel sand up over the shelters.

As for 3-D space printing, “We see it as something to keep an eye on, but we consider it not quite state of the art,” said Grant Anderson, president of Paragon Space Development Corp. in Tucson, Ariz., which is conducting a feasibility study on life-support systems for the reality production.