By Steffan Slater, MDRS Crew 130 Engineer, Georgia Tech University
While 3D printing has the potential to revolutionize many fields, one of the most promising areas is space exploration. The ability to make items in situ from local materials in remote locations, such as on Mars, could reduce payload mass enormously – and every pound of payload is worth dozens of pounds on the whole rocket. From May 4 to May 18, a crew of six students from Georgia Tech traveled to the Mars Desert Research Station in Hanksville, Utah to test the utility of 3D printing in an isolated environment, along with other research projects.
The Mars Desert Research Station is operated by the Mars Society for the purpose of advancing the knowledge of how to live and operate a manned outpost on Mars. Crews from around the world travel to Utah and spend two weeks performing self-guided research at the station. During their stay, crews are required to remain “in sim” as much as possible, wearing simulated space suits when going outside, conserving water and electricity, and eating only freeze-dried and nonperishable food. This year’s Georgia Tech crew, Crew 130, performed a variety of research, much of it centered on investigating 3D printing technology in the Mars simulation environment. This was accomplished with two 3D printers, one of which was a Printrbot LC generously donated to the Georgia Tech Mars Society by Printrbot.
The Printrbot performed admirably despite technical difficulties. Shortly before the crew’s departure for Utah, either the bed thermistor or the control board connection to said thermistor was damaged during testing, causing a permanent bed temperature reading of approximately 80 degrees Celsius. While Printrbot offered to ship the crew a new thermistor, the crew elected to remain in simulation, tolerating and working around the failure. Since the bed heating element was still functional, an infrared temperature sensor was used to provide bed temperature measurements and allow for rough control of the bed temperature. This proved to be reasonably effective and demonstrated that the printing process could tolerate some level of component failure – important for a Mars mission.
Several of the printing projects were directly related to Crew 130’s high school outreach efforts. One of these efforts, through the NASA INSPIRE program, involved implementing proposals for projects by students and reporting the results. The selected proposal was the testing of different rover wheel tread designs. Four different tread designs were developed. A crew member designed the treads and a wheel hub (allowing the interchange of the treads) in CAD software and 3D printed the designs, which were tested on a remote control vehicle purchased by the crew beforehand. Designs were tested for both speed and traction on slopes. Most designs showed little to no improvement over the baseline rubber wheels, but one design performed significantly better on the speed test and slightly better on the incline.
Another outreach application was the testing of various wind turbine designs created by high school students at Bob Jones High School in Madison, Alabama. The students, in an advanced engineering class taught by Mr. Jeremy Raper, designed six different wind turbines. The designs were printed and attached to a small electric motor and voltmeter. The turbines were then taken to the top of a small hill near the base during fairly strong winds and the max generated voltage was recorded, with some designs producing over half a volt – impressive for turbines only several inches across.
A final application of the technology was for a vehicle repair mission. The crew designed and built a cart for towing behind an ATV from wood and metal materials present at the base (left over from previous crews). This cart was attached to an ATV and taken out a short distance from the base, where two equipment failures were simulated, one with the ATV team having contact with the base, one without. The ATV team did not know in advance what part on the cart would fail and had to select spare parts and tools from a selection provided by the repair mission’s designer. The failed parts, which were originally metal and were replaced by printed components, were a wheel axle retaining ring (keeping the wheel attached to the axle) and the cart hitch retaining pin (keeping the cart attached to the ATV). These parts were replaced with their printed spares while in full simulation suits, and the replacements performed very well, allowing the cart to travel all the way back to the base with no problems at all. While the plastic parts might not be suitable for extended uses or heavy loads, they were excellent backups created on-site without prior knowledge of the design.
All in all, the use of 3D printing technology during the Crew 130 expedition to the Mars Desert Research Station was considered to be a huge success. Even with this success, this year was intended only as a trial run, and with the experience gained this year and the donated Printrbot printer, the Georgia Tech crew intends to expand the use of 3D printing at MDRS in future years to objects of significantly higher complexity and utility.
For more information, please visit the Crew 130 information page on the Mars Society website.
[ilink url=”http://mdrs.marssociety.org/archives/crew-130/final-mission-report”]Final Mission Report[/ilink]
[ilink url=”http://mdrs.marssociety.org/archives/crew-130/missiongoals”]Mission Goals[/ilink]
[ilink url=”http://mdrs.marssociety.org/crew-reports”]Daily Crew Reports[/ilink]
[ilink url=”http://flic.kr/s/aHsjEZHwZt”]Crew Photostream[/ilink]