TIME Science space NASA Is 3D-Printing a Better Rocket Test engineer Ryan Wall, left, and propulsion systems engineer Greg Barnett prepare a rocket injector made using the 3-D printing or additive manufacturing process for a hot-fire test at NASA's Marshall Space Flight Center. Emmett GivenMSFC/NASA NASA and the U.S. Army are now using additive manufacturing to manufacture lighter, cheaper, and better-performing aircraft parts

Consider the injector. Its a lowly little engine part about as big as a basketball, small compared to the more photographic components that surround it. Its job, however, is big. On a rocket, it shoots hydrogen gas and liquid oxygen into a combustion chamber to create the thrust needed to send that rocket into space. It also needs to endure the trip.

A conventional rocket engine injector may be comprised of a hundred different pieces, making it costly to assemble. On an object that costs several hundred thousand dollars per launch, and billions in development costs, any savings are welcome. Its one reason why the cash-strapped National Aeronautics and Space Administration has been toying around with rocket parts made using an additive manufacturing process, better known as 3D printing.

In August, the agency test-fired a 3D-printed injector that withstood a record 20,000 pounds of thrust, which actually isnt all that impressive. Paired with rocket boosters and the rest, the complete Space Launch Systema new heavy-lift vehicle that will power NASAs deep-space missions starting in 2017will create 9.2 million pounds of thrust at liftoff, the equivalent in horsepower of 208,000 Corvette engines revving up at once. What is impressive is the fact that the injector had just two parts and could produce 10 times as much thrust as any previously 3D-printed injector.

For NASA, additive manufacturing represents a way for the agency to stretch its technological capabilities and its $17 billion budget as it looks to build the next class of rocket engines to take its aircraft onto asteroids and to Mars. The advances in the technology are finally getting to the point where we can see parts additively manufactured for demanding NASA applications, says Dale Thomas, associate technical director at NASAs Marshall Space Flight Center in Huntsville, Ala., where NASA has been trying out a variety of 3D-printed propulsion parts for more than a year. What the agency lacks, however, is the knowledge required to judge just how well 3D-printed engine parts will stand up during space flight. We dont understand the material properties really well and how they behave under stress, Thomas says.

Enter the Integrated Product Team, a partnership formed in late May between the Marshall Center, the University of Alabama in Huntsville (as in Go Chargers, not Roll Tide), and the U.S. Army Aviation and Missile Research Development and Engineering Center, known as AMRDEC. The question at the central of the partnership: Is there a way to 3D-print material strong enough to insert into a working aircraft?

There is good reason to be uncertain about3D-printing parts that can be used in missiles topped with warheads or rockets ferrying astronauts. Which powdered metals will be easiest to print and strongest to deploy? What 3D-printing machines will work the best? The three groups believe that, by pooling their resources and trading notes, they will save time and taxpayer dollars developing additive manufacturing processes useful to the private sector, the military, and space exploration. They also believe they will manufacture higher-quality partslighter, strongerthan those created today through conventional machining techniques.

For the military, that means lighter missile components that can still handle vibrations during flight.

You always want to save weight for an aviation platform. How do you save weight? Machine the part in a way to minimize frequency vibrations, says James Lackey, acting director of AMRDEC in Huntsville. Only through additive layering can you take advantage of what a mathematical formula tells you this design solution needs.

Conventional machining can be thought of as subtractive manufacturing. You begin with a block of some material and gradually chop some off, a process that constrains the types of parts that can be designed. Additive manufacturing is different. Imagine instead a laser-centering machine that heats up and fuses together successive layers of powdered metalsinconel alloys, grades of steel, titanium, aluminumto construct simpler rocket engine components. This is how NASA created the injector it test-fired a year ago.

Read more:

NASA Is 3D-Printing a Better Rocket