MIT Team Designs a New, Sleek, Skintight Spacesuit

iamdrscience writes "MIT aeronautics professor Dava Newman has designed a new spacesuit along with her colleague, Jeff Hoffman and a group of students. This is far sleeker and lighter weight than the suits used by astronauts today, promising greater mobility than the traditional bulky suits of today which can weigh 300lbs or more. Instead of gas pressurization, the new prototype BioSuit employs "mechanical counter-pressure" in the form of skin-tight layers wrapped around the body."
http://web.mit.edu/newsoffice/2007/biosuit-0716.html

Comments

It sure took a while

[overshoot]

Back when John Campbell was editor of Analog, one of the "Science Fact" articles proposed that spacesuits could be made of gas-permeable mesh that would let skin do what skin does: selective permeability. (Obviously, some parts such as the head still get air!) Provide pressure support but don't try to create an interior environment, and you eliminate a huge number of the worst design challenges of a spacesuit.

You also make it a lot less vulnerable to life-threatening damage.

Chalk up another one for the old Analog, right along with Giant Meteor Impact.

Re:Another plug for the metric system

[Chris Burke]

but isn't pounds (as in lbs.) a measurement of weight

According to Wikipedia, "pounds" originally and still may refer to force (weight). However the "pound avoirdupois", avoirdupois being the system used in the United States, is defined to be a measure of mass.

And on that note, how is having 300 lbs (or mass-equivalent) less gear going to keep you from hopping off the moon into outerspace forever? Didn't the extra mass come in handy to keep people from flying away?

Escape velocity from the moon is 2.4 km/s. I don't think that merely weighing 1/6th as much as you do on earth would allow you to launch yourself at that speed. The astronauts would be able to leap even farther than they could in the bulky spacesuits, though.

Re:head protection?

[Detritus]

You've seen too many bad movies. A hole would result in some localized swelling of the exposed tissue. I'd be more concerned about severe sunburn, which can happen quickly in space.

Re:Sci-Fi correlation

[X0563511]

To be worn in space, the BioSuit must deliver close to one-third the pressure exerted by Earth's atmosphere, or about 30 kPa (kilopascals). The current prototype suit exerts about 20 KPa consistently, and the researchers have gotten new models up to 25 to 30 KPa. This isn't just a proof-of-concept, this is a real prototype under testing.

Re:PHYSICS: Why skin tight may be a bad idea

[icegreentea]

cause in order to continue breathing, pressure within the lungs must equal pressure exerted on the body. you increase external pressure, you can increase air pressure with it (like in scuba). you decrease pressure, i guess you can decrease pressure to a certain degree. of course, 0psi external pressure = 0psi in the lungs = no gas = no good. hence the need to maintain pressure on the human body by w/e means.

RTFA

[overshoot]

* Cooling and heating. The body has a very narrow temp range that is comfortable. You are not going to be comfortable in spandex with your sunward side near boiling and your shadowed side near absolute zero.

Ahem. Vacuum is a wonderful insulator. Your sunward side gets only a little more sun than it does at the beach, and that's assuming you don't have a (nonpressurized) reflective layer to minimize radiative transfer. The opposite side doesn't radiate that much more than it does on a clear night, same comment about screening.

* Ventilation. People sweat. You need a constant flow of air across the skin to take away the humidity, otherwise it's like wearing all-polyester clothes. Very uncomfortable after five minutes.

Air? We don't need no steenking air! Has it occurred to you that several light-years of vacuum is about as good as it gets in terms of removing bodily outgassing? (Yes, that includes flatulence. No more jokes about "as funny as a fart in a vac suit.")

* Speed of access. If your craft springs a leak it might be crucial to be able to do this stuff in a hurry. Ever try putting on a wet swimsuit when you're already wet?

In an emergency with the current suits, you're screwed. They aren't exactly quick-on devices either.

* Joints. If the elbows are not constant-volume, you waste energy bendig your elbows. oops.

Most of the problem from current suits comes from the fact that they aren't form-fitting. Your elbow is already constant-volume, after all. It's that layer of (pressurized) air around it that makes the suit so tiring to work in.

Re:PHYSICS: Why skin tight may be a bad idea

[crashfrog]

Obviously I don't understand how this thing works or can work.

I think it's just that you don't understand how lungs work.

When you inhale you don't inflate your lungs by increasing their volume, like opening a bellows.

The way you inhale is by lowering the pressure in your chest cavity by means of the diaphragm, which contracts downwards, increasing chest volume. As the pressure in your chest (outside your lungs) decreases, air forces itself into your lungs and inflates them.

It seems to me that if this thing is mechanically applying 16 PSI in vacuum then it must apply 32 PSI when inside the capsule.

Yeah, but there's air inside your body pushing out, too, remember. That's what the 16 PSI is there for, in fact - to restrain the gases within your body. That's why the suit has to be pressurized - to push back on the pressures within your body that, normally, the atmosphere will push back against.

So, inside the capsule, you're facing 32 Psi minus the 16 psi pushing out from inside you, so you're only against the 16 psi tension of the suit. I imagine it's like breathing with an ace bandage (or, like, a bra) around your chest - more difficult but certainly not impossible.

And secondly even if you solved that, then you still have the problem of the 32 psi pressure making it harder to dissolve gas in your blood, so your cells cant get air or release CO2.

Higher PSI makes it easier, not harder, to dissolve gases in fluids.

Finally, I can't see how this works around your head. If the suit is not pressurized then how do you maintain 16psi pressure on the face?

Big bubble helmet pressurized to 16 psi, like always. I don't see the problem.