Apollo and Shuttle acend suits?

I notice that shuttle crews walk out to the bus that takes them to the
pad with no suit helmet or gloves on, but the guys on the Apollo
missions were all helmeted and sealed up, why? I am assuming that
they were breathing 100% o2, and the shuttle crews are breathing air.

--

Christopher

Christopher writes:

I notice that shuttle crews walk out to the bus that takes them to the
pad with no suit helmet or gloves on, but the guys on the Apollo
missions were all helmeted and sealed up, why? I am assuming that
they were breathing 100% o2, and the shuttle crews are breathing air.

Exactly right--pre-shuttle astronauts had to start breathing pure O2 to
purge the nitrogen from their bloodstreams before they got to space,
where the cabin pressure was 5 psi and would have caused the bends if
their blood was saturated with N2 at ~15psi.

"Christopher" wrote in message
...
I notice that shuttle crews walk out to the bus that takes them to the
pad with no suit helmet or gloves on, but the guys on the Apollo
missions were all helmeted and sealed up, why? I am assuming that
they were breathing 100% o2, and the shuttle crews are breathing air.

Correct. Since Apollo ran at a partial pressure in orbit, they wanted to
start purging as much N2 from their body as early as possible.



--

Christopher

On Fri, 30 Dec 2005 16:36:11 GMT, Christopher
wrote:

Right, thanks for the clarification reply's.


--

Christopher