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TANTALIZING BENEFITS EXIST producing stuff in zero gravity. Here in Parts 1 and 2 today and tomorrow are tidbits gleaned from several sources, including work taking place on the International Space Station.
The Tradeoffs. Not that microgravity hasn’t its challenges: Specifically, something as straightforward as using a screwdriver or wrench becomes difficult. On Earth, we depend on gravity to keep us in place while doing the twisting. On the ISS, we need to secure ourselves. Otherwise, it’s we who do the twisting, not the tool.
PBS SoCal offers an entertaining little video produced not on the ISS but on a modified K-135 jet flying the precise arc producing zero gravity on its occupants.
Engineers have had to development different bracing systems—a whole new set of tools—to assist astronauts working in space.
On the other hand, you can’t “drop” things. They don’t fall, they just continue following the path of their own inertia. Which may mean they’re gone forever if during an EVA (extravehicular activity). Tethers are essential features for astronauts and their tools.
Extrusion in Microgravity. MIT Media Lab describes its work in Microgravity Extrusion, active between January 2021 and December 2022: “Traditional additive manufacturing processes, especially those that make use of liquid resin as the feedstock, are constrained by the gravity environment on Earth. Gravity prevents extrusion into free space without sagging, which requires the use of support material to prevent it.”
However, Media Lab researchers continue, “In a microgravity environment, extrusions into free space that would normally sag can proceed unimpeded, allowing for the creation of structures that could not be produced in a gravity environment.”
The researchers created “flexible ‘skins’ in the desired shape that would then be filled with liquid resin and cured with UV light through the skins. These skins are very lightweight and flexible and are incapable of holding their shape in 1g [hence, here on Earth], but still form the resin into the desired geometry.”
“These skins can be produced on Earth and transported to space compactly,” the researchers note, “before being unfurled and used to create the shapes out of resin. After the resin cures, the skins can be cut away leaving the finished part.”
Tomorrow in Part 2, NASA continues the tale by taking extrusion aboard the ISS. We also learn about liquid behavior there. And other researchers design equipment for the isolation of ISS use and beyond. ds
© Dennis Simanaitis, SimanaitisSays.com, 2023