Posts Tagged‘mit’

The Spacesuit of the Future.

The spacesuit of today is much the same as the one of the last few decades. It’s an incredibly complicated device, combining all the systems necessary to keep an astronaut alive in the vacuum of space into a wearable package. However it’s not the easiest thing to use, often requiring extensive training not only to get familiar with it but also to train your muscles in how to use it. This is mostly because the design, which makes even the slimmest astronaut look something like the Michelin Man, is centred on ensuring that the pressure on the astronaut’s body is kept constant. This is currently done using an inflated lining which is quite restrictive however future designs, like the one from MIT, could provide the same protection whilst giving astronauts far more freedom.

MIT BiosuitOur bodies are accustomed to 1 atmosphere of pressure which, on the grand scheme of things, really isn’t that much. Indeed the difference between what we’d consider normal pressure and a complete vacuum is about the same as going 10m under water, something SCUBA divers do on a regular basis. However the trick is ensuring that that pressure stays consistent and constant over your entire body which is what led to the spacesuits today. Interestingly though it doesn’t matter how that pressure is generated so the traditional method can easily be replaced with something that’s mechanical in nature, which is what the new BioSuit from MIT seeks to do.

Instead of covering the astronaut’s body in what amounts to dozens of inflated pillows the BioSuit instead looks to use Shape Memory Alloys (think nitinol wire, if you’ve ever played with it) to provide the pressure. Essentially they’d have a full body tourniquet that would be embedded with this wire and, upon heating, it would contract around the astronaut’s body, providing the required pressure. How that pressure would be maintained is still a problem they’re working out (as keeping the astronaut heating constantly isn’t exactly ideal) but seem to be making good progress with various clip designs that would keep the suit tight over the duration of a spacewalk. They’d still have to have the traditional fish bowl on the head however as employing a system like this on the head wouldn’t really be feasible.

Whilst a suit like this wouldn’t provide complete freedom of movement (think a wetsuit that feels like it’s a size too small) it would be a vast improvement over the current design. Right now every time an astronaut wants to move a part of their body they essentially have to compress the protective bubble of gas in their suit, something which ends up being extremely tiring over the course of a long duration spacewalk. A design like this would likely require far less energy to manipulate whilst also allowing them to move a lot more freely, significantly reducing the time they’d need to spend outside.

For me though it’s just yet another piece of sci-fi making its way into reality as we’ve long dreamed of spacesuits that would be like a second skin to its wearers. Better still it’s being made with technology that we have available to us today and so no exotic material sciences is required to bring it to fruition. We likely won’t see any astronauts wearing them any time soon (the cycles for these things are on the order of decades) but as time goes on I think it’ll be inevitable that we’ll move to suits like this, just because of the vast number of advantages they offer.

 

The Human Powered Helicopter.

We humans aren’t great power sources, despite what The Matrix might have you believe, with our sustained output being roughly equivalent to about one quarter of a horsepower (maybe half if you’re an endurance runner or cyclist). This works pretty well for our natural form of locomotion as we don’t need that much to move ourselves around but it becomes something of an issue when we start using more exotic forms of transportation. Cycling and rowing can be fairly efficient forms of transportation when all you have is human power however once you want to take to the skies things start to get a little hairy as the power required for sustained flight is usually well above what your typical human can provide.

That’s not to say we haven’t tried, far from it. Attempts to create a purely human powered craft go as far back as 1923, a mere 20 years after the first powered, heavier than air flight took place at Kitty Hawk. Most of these experiments could only be considered experimental in nature as the distances they could cover were rarely more than a few meters and most of them required a powered assist in order to take off, thereby invalidating them as being truly human powered. The late 1970s however saw the creation of the Gossamer Condor and Albatross, both fully human powered craft that took the Kremer Prize. However probably the most famous of all the human powered craft comes in the form of the MIT’s Daedalus a human powered craft that flew from the Isle of Crete to Santorini, a distance of 115KMs that was completed in just under 4 hours.

You’d then think that a human powered helicopter wouldn’t be too far behind however the design principles behind a helicopter present a much larger challenge than those of a traditional aeroplane. Instead of pushing the aerofoil via the use of a propeller to generate lift a helicopter instead whips the aerofoil itself through the air. This, traditionally, requires a lot more effort in order to generate the same amount of lift and the tricks used for the current generation of human powered craft (light materials and giant wings) present even greater challenges when those wings need to be under rotational stress. We do have several decades of aeronautical engineering advances since then however and one team has finally managed to create a human powered helicopter, one that can fly for just over a minute:

It’s an incredible device sporting 4 rotors that each have a diameter of 20m, each of which is larger than the individual rotors of the mighty Boeing Chinook. That incredible size is also coupled with a weight that seems almost impossible for a craft of that size, weighing in at a paltry 55kg. One thing to note however is that whilst this does count as a human powered helicopter the height it attained, some 3 meters or so, means that this craft was still operating well within the ground effect which means that it’s effectively working with a much better lift profile than would be expected once it reached a higher altitude. Some would then not classify this as a helicopter and instead call it a ground effect craft, which I’d agree with in some sense, but it’s still a pretty amazing feat of engineering despite the fact that it hasn’t left ground effect yet.

It’s really quite amazing to see how a combination of engineering and human power can create things like this which were the stuff of fantasy not too long ago. Sure it might not have any practical uses right now but the technology they developed will definitely flow down to other lightweight craft, further improving their flight capabilities and characteristics. We might never all have our own pedal powered aircraft but it still remains a valuable engineering challenge, much like the solar car races held here in Australia. I can’t wait to see what they develop next as there’s already been implementations of other exotic aircraft like the human powered ornithopter so others can’t be that far behind.