The American Space Agency, NASA, will be sending a 3D printer into space during the Fall of 2014 to provide astronauts and scientists with a way to craft specific tools and spare parts in zero gravity. The mission will also focus on creating small test satellites from this 3D printer that are capable of transmitting data back to Earth (if the experiment is successful). With these advancements, NASA can significantly lower the transportation costs by reducing the amount of items that need to be pre-fabricated and sent up to the astronauts. The machine is only about the size of the MakerBot Replicator home models or about the size of a standard toaster oven. Despite the size, having the adaptability to design and manufacture on the fly can be an essential lifesaving benefit.
Earlier in this month, Rachel Kraft from the Marshall Space Flight Center in Washington reported that the largest 3D printed rocket engine component, blazed to life on August 22 of 2013, generating a record 20,000 pounds of thrust. The component tested, was a 3D manufactured injector which is responsible for delivering propellants in the rocket that power an engine and provide the thrust necessary to propel an object. The testing engineers injected liquid oxygen and gaseous hydrogen into the combustion chamber to measure the force of thrust produced. The results concluded that this rocket created 10 times more thrust than any other 3D manufactured rocket from preceding tests.
The force produced was enough to let the team start fabricating design layouts or templates for these mini test satellites that can now be rocketed out from the Space Station. The success of this test also provided a crucial step in bringing NASA closer to proving this innovative technology can be used to reduce the cost of flight hardware as well as the tools needed in emergency scenarios.
As a side, safety and practicality test, the Marshall engineers at the Marshall Space Flight Center have been running through mock Apollo 13 simulations, in which the crew had to quickly fabricate a lifesaving carbon dioxide filter holder using a plastic bag, a manual cover, and gaffer tape. In these simulations, the crew was able to use the 3D printer to manufacture the exact parts they needed in minutes, giving the crew more time to land safely on the moon’s surface. Although these are just test situations, having the right components can mean life or death which brings us to the next stage of pre-launch testing.
NASA has already been able to fine tune some of this technology, being able to print with laser-melted titanium and nickel-chromium powders that give projects significant strength improvements. Being able to print in zero gravity however, presents a whole new set of challenges. Typically the 3D printer will layer thin sheets of the desired material on a build platform until an object is complete. With zero gravity, there is no additional force (like gravity) that can assist the printer in laying down liquid hot layers of plastic or metal onto a lower platform. Once the melted material jets through the nozzle it will have infinite directions to travel in. With metal material, polarization could be the key to keeping the structure together in such environments, although materials like propylene (or plastic) prove to be more difficult.
Propylene is an interesting material, mostly known for its use with Tupperware and other clear plastic containers. With the latest exploratory satellite named Cassini, atmospheric researchers at NASA have discovered a plethora of Propylene on one of Saturn’s moons known as Titan. In 1980 the Voyager (a previously made, exploratory satellite) discovered Hydrocarbons in the air around Titan, which were derived from methane, once the methane had been broken apart by sunlight. This continuous process that still occurs on Titan forms long chains of molecules that make up propane, propylene, and propyne. Voyager was only able to discern the largest and smallest chains at the time being Propane and Propyne. With Cassini, researchers were able to compare new readings to Voyager’s in order to quickly isolate and identify elements that Voyager left behind.
The first molecule to be discovered using this CIRS system (Composite Infrared Spectrometer which identifies heat coming from the atmosphere), is Propylene, perhaps the most common plastic manufactured on Earth. This plastic is most commonly used to create clear plastic holding containers, such as water bottles. Any item with an identifying mark that contains a number five encased by a segmented triangle with the initials PP underneath is made of Polypropylene. Polypropylene is simply a series of Propylene molecules connected together in a longer chain to form a clear plastic sheet or wire.
We touch and use the same types of elements found on Saturn every day, without even knowing it. And who knows, maybe one day we can stop by Titan to refill a ship’s stock of PLS plastics.