The Past, Present, And Future Of Inflatable Space Habitats

January 30, 2024 by Tom Nardi 23 Comments

Recently, a prototype inflatable space station module built by Sierra Space exploded violently on a test stand at NASA’s Marshall Space Flight Center in Alabama. Under normal circumstances, this would be a bad thing. But in this case, Sierra was looking forward to blowing up their handiwork. In fact, there was some disappointment when it failed to explode during a previous test run.

That’s because the team at Sierra was looking to find the ultimate bust pressure of their 8.2 meter (26.9 foot) diameter Large Integrated Flexible Environment (LIFE) module — a real-world demonstration of just how much air could be pumped into the expanding structure before it buckled. NASA recommended they shoot for just under 61 PSI, which would be four times the expected operational pressure for a crewed habitat module.

By the time the full-scale LIFE prototype ripped itself apart, it had an internal pressure of 77 PSI. The results so far seem extremely promising, but Sierra will need to repeat the test at least two more times to be sure their materials and construction techniques can withstand the rigors of spaceflight.

Sierra is a targeting no earlier than 2026 for an in-space test, but even if they nail the date (always a dubious prospect for cutting edge aerospace projects), they’ll still be about 20 years late to the party. Despite how futuristic the idea of inflatable space stations may seem, NASA first started experimenting with the concept of expandable habitat modules back in the 1990s, and there were practical examples being launched into orbit by the early 2000s.

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Need A Low-Mass Antenna In Space? Just Blow It Up!

October 31, 2023 by Jenny List 28 Comments

A parabolic antenna is a simple enough device, a curved reflector designed to focus all the radiation from the direction it’s pointed into a waveguide or antenna at its feedpoint. They’re easy enough to make for a radio amateur, but imagine making one for a spacecraft. It must fold into a minimal space and weigh almost nothing, both difficult to achieve. An engineering academic doing work for NASA, [Christopher Walker], has a new way to make the parabolic surface that solves the spacecraft designer’s problems at a stroke, it forms its parabolic reflector on the inside of an inflatable structure. In this way relatively huge reflectors can be built in space, with easy folding and very little weight. Continue reading “Need A Low-Mass Antenna In Space? Just Blow It Up!” →

Soft Robotics Hack Chat

October 25, 2021 by Dan Maloney No comments

Join us on Wednesday, October 27 at noon Pacific for the Soft Robotics Hack Chat with Ali Shtarbanov!

By this point in technological history, we’ve all been pretty well trained in how to think about robots. Designs vary wildly, but to achieve their goals, most robots have one thing in common: they’re rigid. Whether it’s a robot arm slinging a spot welder on an assembly line or a robot dog on patrol, they’re largely made of stiff, strong, materials that, more often than not, are powered by electric motors of some sort.

But just because that’s the general design palette for robotics doesn’t mean there aren’t other ways. Robots, especially those that are intended to be used in close association with humans, can often benefit from being a little more flexible. And that’s where the field of soft robotics shines. Rather than a skeleton of machined aluminum and powerful electric actuators, these robots tend more toward silicone rubber construction with pneumatic activation. Some soft robots are even compliant and safe enough to be wearable, giving humans the ability to do things they never could before, or perhaps restoring functions that have been lost to the ravages of entropy.

Soft robotics is a fascinating field with the potential to really revolutionize things like wearables and collaborative robotics. To help us understand a little more about what’s going on in this space, we’re pleased to welcome Ali Shtarbanov to the Hack Chat. Ali is a Ph.D. student at MIT’s famed Media Lab, where he studies Human-Computer Interaction. He’s particularly interested in making soft robotics as fast and easy to prototype as traditional robotics have become, and to this end, he invented FlowIO, an open-source platform for pneumatic control. We’ll use this as a jumping-off point to discuss the whole field of soft robotics, especially where it is now and where Ali sees it going in the future.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, October 27 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Fusing Plastic Sheets With A 3D Printer (Sort Of)

May 14, 2020 by Tom Nardi 17 Comments

If you want to experiment with pneumatic devices, you’ll likely find yourself in need of custom inflatable bladders eventually. These can be made in arbitrary 2D shapes by using a soldering iron to fuse the edges of two plastic sheets together, but it’s obviously a pretty tedious and finicky process. Now, if only there was some widely available machine that had the ability to accurately apply heat and pressure over a large surface…

Realizing his 3D printer had all the makings of an ideal bladder fusing machine, [Koppany Horvath] recently performed some fascinating experiments to test this concept out in the real-world. Ultimately he considers the attempt to be a failure, but we think he might be being a bit too hard on himself. While he didn’t get the sheets to fuse hard enough to resist being pulled apart by hand, we think he’s definitely on the right track and would love to see more research into this approach.

For these early tests, [Koppany] wrapped the hotend of his Monoprice Maker Select Plus with some aluminum foil, and covered the bed with a piece of cardboard. Stretched over this were two sheets of plastic, approximately 0.5 mil in thickness. Specifically, he used pieces cut from the bags that his favorite sandwiches come in; but we imagine you could swap it out for whatever bag your takeout of choice is conveyed in, assuming it’s of a similar thickness anyway.

There were problems getting the plastic pulled tight enough, but that was mostly solved with the strategic placement of binder clips and a cardboard frame. Once everything was in place, [Koppany] wrote a Python script that commanded the printer to drag the hotend over the plastic at various speeds while simultaneously adjusting the temperature. The goal was to identify the precise combination of these variables that would fuse the sheets of plastic together without damaging them.

In the end, his biggest takeaway (no pun intended) was that the plastic he was using probably isn’t the ideal material for this kind of process. While he got some decent seams at around 180 °C , the thin plastic had a strong tendency towards bunching up. Though he also thinks that a convex brass probe inserted into the hotend could help, as it would smooth the plastic while applying heat.

We’ve already seen some very promising results when using LDPE film in a CO2 laser cutter, but if a entry-level 3D printer could be modified to produce similar results, it could be a real game changer for folks experimenting with soft robotics.

Custom Inflatables Are Only A Laser Beam Away

April 2, 2019 by Tom Nardi 26 Comments

Carl Sagan one said “If you wish to make an apple pie from scratch, you must first invent the universe.” It might not be a very accurate description of the relative difficulty level of baking, but the logic is sound enough: there’s often a lot of ground work that needs to be to covered before you hit your ultimate goal. A perfect example of this principle is the inflatable raft that [ralph124c] hopes to eventually create; before he can set sail he has to perfect making balloon animals with his laser cutter.

In the long run, the raft will be constructed from sheets of TPU coated fabric that are fused together with a hot iron. But before he spends the time and money on building the real thing, he wants to do some scaled down tests to make sure his design works as expected. He makes a cryptic remark about learning the hard way that inflatables are prone to bouts of strange behavior, and out of an overabundance of caution we’ll just take his word for it.

He hoped to test his designs with the much cheaper LDPE film, but he found that the hot iron didn’t fuse it together in the way he was hoping. His mind turned to his 60 watt laser cutter, and wondered if the desired effect could be achieved by turning the power down as low as possible and quickly moving across the material.

His first attempts either blew right through the film or did absolutely nothing, but eventually he had the bright idea to move the laser farther from the LDPE. This put the beam out of focus, which not only expanded the area it would cover, but reduced the energy being delivered to the surface. With a bit more experimentation, he found he was able to neatly weld the pieces of material together. He even found that he could increase the power slightly to cut through the film without having to adjust the laser focus. With the ability to create complex inflatable shapes, perhaps [ralph124c] will create balloon version of Carl Sagan or an apple pie to celebrate.

Of course, this technology isn’t limited to birthday balloons and model rafts. The ability to quickly and easily produce custom inflatable shapes could be a huge boon to anyone working in soft robotics, and we’ve even seen similar concepts applied to haptic feedback systems.

[Thanks to Arthur for the tip.]

A Big, Mean, Inflated Machine

March 1, 2019 by Lewin Day 21 Comments

A Jeep is fun offroad, a motorcycle perhaps even more so. Diehard renegades go even further and get about in Unimogs and on snowmobiles. [amazingdiyprojects] might just have topped them all however, with his latest project – the astonishing Inflatable Car.

Despite the name, it’s a vehicle that defies clear definition. Consisting of a lightweight aluminium frame and exposed seat, the construction is almost 100% hacked. PVC fabric is used with advanced adhesive tapes to create inflatable wheels that are 2 meters in diameter. Vacuum cleaners are used to inflate the massive tyres, with custom 3D printed valves to ensure even inflation. Drive is courtesy of four handheld concrete mixers, repurposed for their torquey motors and robust geartrains. Even the user interface is a triumph of found parts – consisting of former cordless drills, used for their PWM hardware and covered in extra switches.

Looking like a moon lander from a strange 1950s version of the future, the machine is impressively nimble for its size. Episode 1 starts with a single wheel hooked up to the inflation gear and a single drive motor. Just a few short months later, episode 7 has the prototype machine crawling out from the confines of the back garden and out into the street. The machine is already impressively fast and capable, and we can’t wait to see what happens next.

It’s a build that is truly impressive in its scale, though we’ve come to expect no less from [amazingdiyprojects]. Video after the break.

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