How much of a role does NASA play?

[King_Neptune]

Dr Deco,

You have mentioned that it's our TAX dollars at work at NASA that affords you to do what you do. Can you possibly shed some more light on this. I know you have mentioned to me personally just what kinda of a role NASA plays in research that can benefit us divers but I thought others might like to know what exactly NASA does and just how much of an effort they put into it.

Normally, the general public thinks "NAVY" or "DAN" when they think about any sort of scuba diving beneficial research being done. Can you tell us the role NASA plays and possibly give us a comparison between NASA and the NAVY and DAN or maybe share with us how they all work together?

=-)

 

[Dr Deco]

Dear King:

Thanks for the question about NASA and decompression research. It is not generally known that the astronauts in the space suit are at a reduced pressure. The space Shuttle cabin is at standard atmospheric pressure, as is the Space Station. If the suit were also at that pressure, it would be very stiff and harder than an inflated football. Work would be nearly impossible. By reducing the pressure, flexibility is restored, but the risk of decompression sickness looms, increasing as the suit pressure drops.

Our task at NASA in the Environmental physiology group is to develop techniques to reduce this risk commensurate with time-efficient procedures. The group is composed of several PhD-level scientists, support technicians, and an altitude chamber with crew to operate it. In addition, we contract to outside scientists to assist us in performing research in their own laboratories.

The particular focus of NASA research is HYPObaric (that is, reduced pressure) as contrasted with HYPERbaric, or increased pressure. [Approximately 0.6 to 1 million dollars per year is allotted to this.] NASA and the US Air Force focus on the former, while DAN and the Navy focus on the later. Scuba diving is, of course, in the purview of the later two.

NASA work has focused on questions of micronuclei formation in tissues, since this has been found by our research to be different in null gravity and 1-g on earth. The research work is discussed among research scientists at the two primary meetings of scientists in the barophysiology field, viz, The Undersea and Hyperbaric Medical Society and the Aerospace Medical Association.

The results from the 0-g research on tissue micronuclei can be applied, in some cases, to recreational divers. That is what appears in the “Ask Dr. Deco” columns. NASA is always interested in public outreach to share the results of its work with the general public. It is considered an important part of NASA’s mission.

 

[Gerb]

That's very interesting about the negative suit pressure and the Deco implications. Always just took it for granted that it was positive pressure. Got me curious though, in astronaut pool training, do you adjust suit pressure pos underwater to mimic space conditions neg pressure. Wouldn't that give you entirely different Deco consideration in the pool?

Thanks

Mike

 

[Dr Deco]

Hello Gerb:

Many people are surprised to hear about astronauts on spacewalks and the pressure in the suits. It is actually reduced pressure from the cabin and not negative pressure. The pressure change from the spacecraft cabin (14.7 psi) to the suit (4.3 psi) is equivalent to decompression from sea level to an altitude of 30,000 feet.

In the Neutral Buoyancy Laboratory, the astronauts practice various activities in the EVA suits that are pressurized with nitrox. The suits are at a pressure of 4.3 psi above the pressure of the depth at which they are working.

 

[Gerb]

Thanks for the explanation. fascinating!!! I guess I wasn't clear on the positive and negative, If I'm understanding correctly that is +\- of 1 ATM.

Thanks again and appreciate all your helpful information on DSC

Mike

 

[Dr Deco]

Gerb:
You are correct. 1 ATM (atmosphere) is taken as the reference. Greater than this is HYPERbaric while less that 1 ATM is HYPObaric. None, however, are negative pressures.