Welding

We have entered a point where great nations have one objective: spatial autonomy. And, although many factors come into play, one of the most important is the ability to manufacture and assemble in space. As? Welding directly in space, but although we have seen it in science fiction on numerous occasions, things get complicated when we want to apply it to the real world. Now, a British university believes it has found the solution. A ‘Wall-e‘ welder. Nightmare. Soldering on Earth is an extremely simple process. We only have to apply a very high temperature and both gravity and the atmosphere make it easy for us. In space, the thing changesturning something routine into a real physical nightmare. There are three elements that come into play: Microgravity: on Earth, gravity causes the drop of the binding metal (tin, for example) to fall on the elements to be joined. In space, since there is no gravity, surface tension is the dominant source: the molten metal does not stay in place, but tends to form spheres. Additionally, gas does not escape from the molten metal, causing porosities and further structural weakness. Pressure: There is no oxidation because there is no oxygen, but there is also no pressure, which lowers the boiling point of certain alloys. This can cause, at certain temperatures, some critical components of the metal to evaporate rather than melt. Again: the chemistry of the solder and the properties of the joint are altered. The politics of discard. If that were not enough, welding in space is a nightmare for astronauts who have suits that limit their movements and who would always be under the pressure of a spark or slag piercing the suit. Goodbye astronaut. That is why administrations have become accustomed to the logistics of disposal: rather than repairing something, it is better to throw it away and launch something new from Earth. Less risks, fewer headaches. ISPARK. Clearly, it clashes with the most current policy: that of recycling. A few days ago we saw that, while NASA wants to throw down the International Space Station to the trash, there are those who want to recycle it to take advantage of all the elements it has. And building platforms in space based on smaller parts is more reasonable than launching those pre-assembled structures from Earth. That’s where the discovery from the University of Leicester, in the United Kingdom. In collaboration with TWI Ltd, they have launched what they have called “ISPARK Project”, or “Intelligent SPace Arc-welding Robotic Kit”. It is not a new physical welding, but a robot to do the work. There are still issues that can compromise the integrity of the weld itself, but having a robot do the job eliminates the extreme risk for astronauts. And, precisely, the researchers point out that achieving this “will redefine how large structures are built and maintained in orbit” in the new era of the space economy. They are not the only ones, since companies like ThinkOrbital wave University of Texas they are also pushing this possibility. Roadmap. It must be clarified that it is a technology that has to be tested. The first step will be to subject the robotic system to tests in chambers that simulate the vacuum of space to verify both that the electric arc and that the behavior of the materials are stable in an environment without an atmosphere. In addition to the direct results, they will compare with a digital twin. It is a technology that virtualizes (thanks to computer calculations) the physics of welding in vacuum and microgravity. It is data with which they will train the robot, but also with which they will compare the results of the physical world. And, if everything goes well, in later phases the objective is to test it in orbital reality conditions. This is where other factors come into play such as radiation or dynamic thermal cycles (conditions of extreme cold and heat in a matter of an instant). In search of autonomy. Little joke with this. The “Smart Space Arc Welding Robotic Kit” has received funding through the UK Space Agency’s National Space Innovation Programme. Specifically, 560,000 pounds to develop this system. Everything is framed within a larger program of the Agency, which will allocate 17 million pounds to 17 space innovation projects. If we look at the global European “photo”, it is contextualized within a reality in which we also see that the European Space Agency seeks one thing: autonomy. The British agency and the ESA are tired of depending on NASA either Roscosmos for their space missions, and we are seeing how they develop technologies or inject more than 900 million euros to find a European replacement for SpaceX. And, obviously, assembling and fixing in space is much more sustainable than continuing to create technology that costs hundreds of millions of euros and is disposable. Images | University of Leicester In Xataka | We are launching more things into space than ever before. And the next problem is already on the table: how to pollute less