[FPSPACE] RE: Death in space

Haeseler, Dietrich Dietrich.Haeseler@astrium-space.com
Fri, 22 Sep 2000 09:21:33 +0200


Jens Lerch [mailto:jens.lerch@studmail.uni-stuttgart.de] wrote
> A pressure suit allows survival in a depressurized environment, 
> just like a full EVA suit. The difference between the two is 
> mobility, endurance, and protection of temperature extremes, 
> radiation, and space debris. It is certainly possible to do a short 
> emergency EVA, like leaving one vehicle and entering another vehicle 
> stationkeeping a few feet away, in an ordinary pressure suit. 
> The Shuttle rescue balls were considered at a time when the Shuttle 
> crew was to wear shirt-sleeves the entire time. Today it should be 
> possible to haul the crew in their orange pressure suit from one 
> Shuttle to the other, assuming the second Shuttle is launched 
> in time... 

The main obstacle to use IVA (internal) pressure suits for emergency EVAs is
the fact that transfer from one vehicle to another one through open space
requires an autonomous life support (air, cooling water, electricity, etc.),
which seems not to be implemented into Russian presssure suits. Thus, as
long as those suits require a pressure feedline connected to the
spacecraft's life support systems, at least the connections at the suits
need to be available twice. Then one could connect the suit to the rescue
vehicle's systems before cutting the connections to the failed vehicle.

Two suits are provided for Shuttle crews:  The Launch Escape Suit (LES) and
an Advanced Crew Escape Suit (ACES). LES provided protection above 100.000
ft for 30 minutes, while ACES can do that indefinitely. The Personal
Parachute Assembly (PPA), which can obviously be worn with both suit types
includes oxygen supply for 10 minutes at sea-level and "several times that
at high altitudes". Thus, at least the ACES could work for emergency EVAs.

I do not fully understand from the available documentation, whether both
suits a present aboard the Shuttle, or whether one is selected for each
mission.