Toys and Asteroids: How Does a 3D Printer Work?
3D Printers are getting more common, and are REALLY cool, but how do they work? In principle, it is quite a simple science. Most 3D printers use a plastic filament, and have a nozzle that heats up to about 200 degrees C (about 400 degrees F). This melts the plastic as it passes through the nozzle, known as an “extruder”. The 3D printer is told by a computer where and when to move its nozzle and dump out the hot melted plastic. The plastic rapidly cools, and leaves a solid behind as the extruder moves on to lay down more plastic.
The extruder will start at the bottom and make all of the things it needs to at that elevation (known as a layer), and then move up to start the next layer. Not terribly complicated. The extruder knows where to go because of a 3D file that is run through a program called a “Slicer” that decides what to do at every layer. The printer continues this process for every layer, building the entire thing from the bottom up. This allows for some cool things! As the printer continues on its way, these will be locked in place. Understanding constraints on 3D printing allows for some very interesting challenges, and ultimately some incredibly cool designs.
How NASA Uses 3D Printers
These printers aren’t just for making cool designs. NASA is currently using a brand new 3D printer in orbit aboard the ISS. One of their astronauts needed a wrench, so they sent him the design file, and he made it on board! They even shared the plans for this wrench, allowing us to print our very own at AstroCamp.
3d Printing Asteroids
NASA has always been about accomplishing crazy things. In the 1960s, the idea of people walking around on the moon was ludicrous, but NASA got them there anyway. Now, NASA is performing another crazy feat: sending a probe to an asteroid, collecting rock samples, and returning that probe to Earth. Additionally, the probe has created a digital map of the asteroid which we can recreate, simply by using a 3D printer.
In September 2016, the Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer space probe (OSIRIS-REx for short) was launched aboard an Atlas V rocket. It quickly made its way into space and began its journey towards the asteroid designated 101955 Bennu. This journey lasted over two years as the probe used low-power thrusters and gravity assists from Earth to reach its destination.
OSIRIS-REx reached Bennu in December of 2018, and as it approached, it used its long-range PolyCam sensors to map out the surface of the asteroid. After arriving, OSIRIS-REx used its short-range cameras to take even higher resolution images of Bennu’s surface. NASA scientists used that data to create 3D models and released them to the public!
Since we’re lucky enough to have a number of 3D printers here at AstroCamp, we decided to print our very own Bennu asteroid! You can see the results below, but if you want to have your own version of the asteroid, you can find the files to 3D-print the asteroid here!