Quote from: Robotbeat on 03/24/2013 04:11 amAlso, at the elevation airplanes fly at, pure oxygen is sufficient for human survival for short periods. At the elevation spaceships travel, pure oxygen isn't sufficient and your blood would boil without a pressure vessel of some sort.I've read the blood boiling is a myth. Work is being done on flexible spacesuits that aren't airtight and mainly serve to keep the heat in and to keep the astronaut from swelling up. See Space activity suit and BioSuit.
Also, at the elevation airplanes fly at, pure oxygen is sufficient for human survival for short periods. At the elevation spaceships travel, pure oxygen isn't sufficient and your blood would boil without a pressure vessel of some sort.
I guess I still don't see it. it seems like designing a suit to structurally keep perfectly even pressure on every square inch of skin would be much harder than one with a thin layer of gas between the suit and the skin. Spacesuits aren't large and bulky because they need that much gas in them to maintain pressure. A 1 millimeter layer works just as goes as an inch.
It's about mobility. Ordinary space suits resist movement because they are flexible walled pressure vessels. When you move your arms and legs the volume inside the suit changes which means you have to do work against the internal pressure. Webb/Bio-suit circumvents this using mechanical means, load paths directed so that work is not done when joints move. I'm hoping this tech will go forward. It would also enable using additional external flexible clothing depending on working environment (MMOD protection / thermal etc.).
And Joe 6pack will be more understanding for the need of HSF when he sees female astronauts doing spacewalks in figure hugging costumes...
It's about mobility. Ordinary space suits resist movement because they are flexible walled pressure vessels. When you move your arms and legs the volume inside the suit changes which means you have to do work against the internal pressure. Webb/Bio-suit circumvents this using mechanical means, load paths directed so that work is not done when joints move. I'm hoping this tech will go forward. It would also enable using additional external flexible clothing depending on working environment (MMOD protection / thermal etc.).And Joe 6pack will be more understanding for the need of HSF when he sees female astronauts doing spacewalks in figure hugging costumes...
On a side note, why is the ISS regular air? Any suit would be a lot more convenient if they didn't have to transit from one mix and pressure to the other all the time.
Quote from: ddunham on 03/24/2013 05:40 pmQuote from: Nomadd on 03/24/2013 04:57 pmOn a side note, why is the ISS regular air? Any suit would be a lot more convenient if they didn't have to transit from one mix and pressure to the other all the time.It's a lot easier to use equipment that you know works in 1atm in 1atm. Making/testing/certifying all the equipment to work in reduced pressure would be a significant expense. Cooling in particular can be a big issue.Plus, both the shuttle and Soyuz used regular air... there was absolutely no way either NASA or the Russians were going to build a space station with an atmosphere that didn't match that of their manned spacecraft.
Quote from: Nomadd on 03/24/2013 04:57 pmOn a side note, why is the ISS regular air? Any suit would be a lot more convenient if they didn't have to transit from one mix and pressure to the other all the time.It's a lot easier to use equipment that you know works in 1atm in 1atm. Making/testing/certifying all the equipment to work in reduced pressure would be a significant expense. Cooling in particular can be a big issue.
Another alternative is 3d printed hard suits. Perfect fit, low friction vacuum bearings on all the joints.
That's the idea, right. But I do have a serious problem imagining a suit that achieves the goal of providing very homogenous pressure to every inch of the body. Particularly those parts that protrude a bit.
I imagine these things will be pretty difficult to get in an out of, but I actually think that eventually they will have to be used (at least in some circumstances) because regular suits (and most alternatives to regular suits) are quite cumbersome. Putting on mechanical counter-pressure suits will be a huge pain, but once they're on, you can be far more capable, fit in more places, be able to handle smaller objects and thus fix/assemble things that otherwise wouldn't be feasible to fix/assemble, etc. It's an elegant solution to a very complicated engineering problem.And I think that the 80/20 solution would be mechanical counter-pressure gloves. They have already been tested in some circumstances: http://www.ncbi.nlm.nih.gov/pubmed/15828639"Sensitivity was significantly better for MCP [edit: Mechanical Counter-pressure glove] compared with the EMU [edit:Existing suit glove]."
Quote from: Jorge on 03/24/2013 06:00 pmQuote from: ddunham on 03/24/2013 05:40 pmQuote from: Nomadd on 03/24/2013 04:57 pmOn a side note, why is the ISS regular air? Any suit would be a lot more convenient if they didn't have to transit from one mix and pressure to the other all the time.It's a lot easier to use equipment that you know works in 1atm in 1atm. Making/testing/certifying all the equipment to work in reduced pressure would be a significant expense. Cooling in particular can be a big issue.Plus, both the shuttle and Soyuz used regular air... there was absolutely no way either NASA or the Russians were going to build a space station with an atmosphere that didn't match that of their manned spacecraft.This is totally rational for a space station in LEO, much less so beyond LEO.
Quote from: Robotbeat on 03/24/2013 06:10 pmQuote from: Jorge on 03/24/2013 06:00 pmQuote from: ddunham on 03/24/2013 05:40 pmQuote from: Nomadd on 03/24/2013 04:57 pmOn a side note, why is the ISS regular air? Any suit would be a lot more convenient if they didn't have to transit from one mix and pressure to the other all the time.It's a lot easier to use equipment that you know works in 1atm in 1atm. Making/testing/certifying all the equipment to work in reduced pressure would be a significant expense. Cooling in particular can be a big issue.Plus, both the shuttle and Soyuz used regular air... there was absolutely no way either NASA or the Russians were going to build a space station with an atmosphere that didn't match that of their manned spacecraft.This is totally rational for a space station in LEO, much less so beyond LEO.I heard somewhere one big reason was to not complicate experimental results especially for zero-g health. If we go further than LEO we probably have a different purpose in mind so that motivation would go away....
Must be terribly uncomfortable, what happens if you sweat?