NASA lightweight suit

[Uncle Bob]

This is the Space Activity Suit, AKA Mechanical Conterpressure Suit, AKA the "Skinsuit"

Developed in the late '60s and abandoned for no well-articulated reason. This is the 1971 report as a 9 MB pdf

. Development of a space activity suit
Annis, J. F.; Webb, P.
NASA Center for AeroSpace Information (CASI)
NASA-CR-1892 , 19711101; Nov 1, 1971
The development of a series of prototype space activity suit (SAS) assemblies is discussed. The SAS is a new type of pressure suit designed especially for extravehicular activity. It consists of a set of carefully tailored elastic fabric garments which have been engineered to supply sufficient counterpressure to the body to permit subjects to breath O2 at pressures up to 200 mm Hg without circulatory difficulty. A closed, positive pressure breathing system (PPBS) and a full bubble helmet were also developed to complete the system. The ultimate goal of the SAS is to improve the range of activity and decrease the energy cost of work associated with wearing conventional gas filled pressure suits. Results are presented from both laboratory (1 atmosphere) and altitude chamber tests with subjects wearing various SAS assemblies. In laboratory tests lasting up to three hours, the SAS was worn while subjects breathed O2 at pressures up to 170 mm Hg without developing physiological problems. The only physiological symptoms apparent were a moderate tachycardia related to breathing pressures above 130 mm Hg, and a small collection of edema fluid in the hands. Both problems were considered to be related to areas of under-pressurization by the garments. These problems, it is suggested, can ultimately be corrected by the development of new elastic fabrics and tailoring techniques. Energy cost of activity, and mobility and dexterity of subjects in the SAS, were found to be superior to those in comparable tests on subjects in full pressure suits.
Accession ID: 72N13077
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720005428_1972005428.pdf
Document ID: 19720005428
Updated/Added to NTRS: 2004-11-03

 

[Jeff M. Hopper]

Wow. How in the Hell did you find this? That file is some good reading!

 

[Uncle Bob]

Glad you like it. ntrs.nasa.gov, the technical reports server. Lots of good stuff, some as .pdf or .html, most as paper. Including the VASIMR papers, dammit.

 

[Father Fletch]

This reminds me of the Reformation Coalition Pressure suits. Always made sense to me.
CFK

 

[Fritz_Brown]

You know what this is? It's a g-suit! A g-suit squeezes on the body to restrict blood flow, whereas this does it to increase the pressure you feel. Oh, I can see this is going to take a while to read... Guess I'm not going anywhere soon.

 

[Fritz_Brown]

Hey! This even mentions the Wiley Post vacc suit!

 

[Fritz_Brown]

OK, some points I see. First is that it is good that a tear wouldn't be a big problem because you wouldn't be leaking air. And, I would think patches would be simple, then, too.

But, their comments on exposure of the body to vacuum seems a little dated. I think the bends kick in pretty quickly at extremely low pressures. Also, they state that the force acting on skin in a vacuum would be 2.3g/mm^2. Then they state that human skin tensile strength is several orders of magnitude above that - at 1600g/m^2. Does anybody else notice the difficulty with that? Yeah, they changed units! Because there are 1,000,000 mm^2 in a m^2, it's actually less than required. My guess is they made a units error, rather than a math error.

This is still cool!

 

[Maladominus]

Hmmm. So is this like the Traveller TL9 vacc suit?

Or is this NASA thing actually... *gasp* more advanced than Traveller TL9?

 

[Uncle Bob]

Originally posted by Maladominus:
Hmmm. So is this like the Traveller TL9 vacc suit?

Or is this NASA thing actually... *gasp* more advanced than Traveller TL9?

Notice that this was developed, tested, proved, and abandoned in the late 1960s. TL6

The late G. Harry Stine said it was abandoned because some astronauts refused to wear girly leotards.

Fritz88
As for bends the wearer breathes pure O2 at less than 200 mm Hg/ 0.27 atmosphere. Typical for US spacecraft at the time and still used for spacesuits. No N2, no bends.

As for the units, I don'tq know which is correct. But the suit was repeatedly and successfully tested in vacuum chambers.

 

[Fritz_Brown]

Yeah, Uncle, I noticed that well after I posted. (And, I had forgotten that aspect.) Of course, that does make this still an impractical suit for your everyday spacer - unless you want them living in a pure O2 environment in space. I think there are several problems with that (besides fire).

It would be really cool to see this research picked up and redone with modern fabric tech, though.

 

[Uncle Bob]

All current space suits use 3 psi pure oxygen. Any more makes the suit too hard to move. You have to prebreath O2 for half an hour before EVA.

No change there.

 

[Fritz_Brown]

Well, Uncle, none of our astronauts is an everyday spacer. Not yet, anyway. And, none ever will be if you have to prebreath every time you might be in vacuum. 'Cause I'm thinking this looks just like a skinsuit for normal shipwear - accidental breaches, quick jaunts outside, etc.

 

[Uncle Bob]

Well, maybe in a couple of TL we can get a 14.7 psi suit, other than a "hard" suit.

 

[mwturnage]

Jerry Pournelle wrote about this in length in one of the anthologies he edited back in the late 70s/early 80s. According to him, the fabric used in the tests (including ones done after NASA abandonded the concept) were actually commercial spandex.

 

[Golan2072]

So, if I get this right, this suit's fabric directly applies pressure to your body rather than haousing an atmosphere - so if you puncture the suit anywhere but the helmet (which is pressurized), you don't loose any air or "integrity" - you just get a local vaccuum/cold/radiation burn, which is a bad thing - but not as immidiately lethal as a pressurized-suit puncture.

Do I understand it correctly?

 

[parmasson]

^ sounds right except at that point your blood would star to boil would it not?

Hmmm At TL-12 this could use a smart fabric that is not so tight under normal conditions but in case of emergency could transform into a pressure suit to save your life.

Imagine a pair of long underwear with good breathablity and little pockets behind your head and around your hands. In the even of a possible depressurization, pull the gloves out and on, a ripcord exposes a clear flexible plastic bubble helmet and a little O2 or CO2 scrubber to buy you fifteen or twenty min so you can get to a proper vaccsuit. The fabric when exposed to low pressures becomes airtight and contracts by some future technology or even with battery power. It could be a common feature for marine or naval crews under their regular duty uniforms.