06. June 2019 – Munich, Germany —
Some time has passed since our last update. Please excuse the waiting time, the summer semester has us back under control!
Although you did not hear much from us here, we have not been idle in the last few weeks.
At the beginning of March, we were represented at Make Munich together with Munich University of Applied Sciences and were able to present our project to a broad audience for two days. Over the weekend, our team was almost fully present, and we had some interesting conversations and met lots of nice people. Nevertheless, there was still enough time to look at the projects of the other exhibitors. From man-sized 3D printers or additively manufactured chocolate (maybe try at AIMIS 2.0?) over solder shops and sustainably built surfboards, everything was there! Pictures of the weekend can also be found on our website. Many thanks again to the team of MakeMunich and the Munich University of Applied Sciences for the organization!
You can find pictures of the weekend in our gallery!
Also, within the university we were able to present our project in the last weeks. On the faculty day of our faculty 03 (mechanical engineering, automotive engineering and aerospace) we presented our team in the context of the topic “3D printing in space”, together with the state of affairs in this very young industry. If you would like to know what is possible with a million-dollar budget and many years of experience, below you will find further information on the two largest projects of additive manufacturing in space.
Already so much: NASA works together with Tethers Unlimited on an autonomous robot that extrudes and cures a kind of plastic thread in orbit. The thread can be manipulated with the help of gripping arms and formed into huge, three-dimensional constructs. Matching to its arachnoidity, this device is called SpiderFab.
On a private side, MadeInSpace works on an autonomous 3D printer that can print components in orbit. The components are then mounted by gripping arms to complex structures. MadeInSpace is also the company that installed a 3D printer on the ISS at the beginning of the millennium, where it was able to produce the first 3D printed component produced in space.
We were also able to present our project and the REXUS/BEXUS program to the student body of the university as part of an information event organized by our supervising professor. Although no volunteers have been found for our team, the prospect of the upcoming Cycle 13 produced some bright eyes. Let’s see if there will be a new university team in the next few months!
For the near future, more specifically for the autumn, we are planning to visit two conferences of the aerospace industry. In September, our team will be present at the 3rd SSEA (Symposium on Space Educational Activities) in Leicester, England, where we will give a talk about our experiment.
In October, the 70th International Astronautical Congress (IAC) will be held in Washington, DC, USA. The conference is the largest gathering of members of the space sector worldwide. All major space agencies, launcher companies and research institutes are represented there. Maybe one or the other astronaut is running around there as well. We have the honor to hold two lectures on our experiment and generative manufacturing in space and are very excited!
For now, we are still organizing travel and accommodation to allow as many of our team members as possible!
So much for the news on our team and all the trappings,now it’s time to get down to business.
As far as the development of our experiment is concerned, we have not been idle in recent weeks and have made some progress!
We have done some experiments with our synthetic resins to further validate your suitability for the REXUS flight conditions and our experiment.
Because we were able to find a small vacuum chamber on campus, we were able to do the first vacuum test in April. In the process, we wanted to find out whether the two resins in question would outgas under vacuum and perhaps lose their hardeners. In the worst case, this would have prevented the curing of the resin during the flight and thus rendered the resin useless. For this purpose, we have exposed various samples in the vacuum chamber to an absolute pressure of about 2 mbar. That’s two thousandths of the normal ambient pressure, so pretty much a vacuum!
The pressure is still a bit too high compared to the pressure at the peak of the REXUS trajectory, where we expect an ambient pressure of about 0.5 mbar. Hopefully soon, we will get a vacuum pump that can deliver these pressure conditions. For initial estimates, however, what we have is enough.
The next vacuum test on the list would be a test of the UV LED’s and the cameras. With these components, minor manufacturing defects (such as air bubbles in the lens) can lead to the complete destruction of the part, which we would naturally prefer to find out before rather than during the flight.
And yes, we’ve also had our cameras for a week or two! We use the RunCam Split Mini 2, which is pretty small and lightweight (only 12.5g!).
We want to include one or two of them in the experiment to accurately document the process of extrusion and curing during the flight. A resolution of 1080p and 60 fps of the RunCams is of course ideal, first functional tests also deliver promising images (but disappointing so far only from team members).
Cameras and LED’s, nice and good, but without electricity nothings going to fly anytime soon. Luckily our electrics have made a big leap! Under the tireless efforts of Patricio and Chris, we were able to complete and commission the first draft of our printed circuit board (PCB). The PCB together with the Nucleoboard controls the power supply, the controls and data acquisition of several sensors, the cameras and LEDs, as well as the electric motor.
As soon as the components are soldered there, we will also put them to through their paces and optimize them until we are satisfied with the result.
Fittingly, the mechanical model has changed as well. Our designer Chris could not resist printing and assembling a 3D model of the experiment. The model helps immensely to get a sense of the dimensions of the device! You can also see the E-Box, in which the Nucleoboard and the PCB are installed. In addition, we are still in negotiations to have our experiment made at a very special company. More about this in the next time!
And finally, a few minor developments:
Further experiments with the resin and a newly developed experimental set-up allowed us to finally optimize the power consumption of the LED’s and thus shift the enormous (and already reprimanded) power consumption of the experiment into an acceptable range. Bye-bye 100Watt problem!
In addition, the website has been redesigned and is now even more informative! We tried to describe the experimental setup and the project process clearly and in detail. Have a look around, if you didn’t notice it already! We look forward to your comments and suggestions!
Finally, last week we handed over the second version of our project documentation to the REXUS/BEXUS team, the SED v2. As usual, the document describes all aspects of our project, from budget and resource planning to risk management and the detailed description of the subsystems, to the planned ground tests and scientific evaluation.
V2 is much more detailed and extensive than v1 (grown from 72 to 161 pages!) And serves as preparation for the next important milestone of the project next week: the CDR!
You will hear more about what that is, where it takes place and what highlights are to be expected in the next week!