New Columbia loss report out today

Alain Fournier wrote:

Craig Fink wrote:

Making an ascent/entry vehicle crash worthy, to protect the occupants.
Again, NASCAR comes to mind and they are way ahead of NASA in many
respects. The car is designed to come apart protecting the occupant,
reducing the loads all along the way, during the crash. Something that
could be incorporated in a future design.

Although unintended in it's design, this happened when the crew
compartment separated from the fuselage. 3 gees down to 1 gee. Designing
it structurally and aerodynamically to continue coming apart around the
occupants would keep the force loads down, just like a NASCAR car.

In a car accident, you want to protect the occupants by keeping the g
forces to a minimum. In an orbital reentry accident, the g forces on the
occupants are a secondary issue, not to be ignored completely, but not the
main issue. You want the occupants to have breathable air and you don't
want them to fry. Keeping the pressure vessel around the occupants intact
is a wise choice for a reentry vehicle.

Gee forces can go both ways as the vehicle breaks up. Many parts probably
went the other way. 3 gee to 10 or 20 gees, depending on the ballistic
coefficient. Keeping the Vehicle pressure vessel intact is preferable, but
not necessary, as long as the personal pressure vessel is intact. Keeping
the some temperature resistant part between the occupant and slip stream
keeps them from frying.

The statement that it wasn't survivable is really only applicable for that
particular vehicle, and really isn't even true in this case. There were
survivors who lived through the Columbia Disaster, just not human ones.
http://www.astrobio.net/news/modules...cle&sid= 1821

A couple of seats essentially few together, side by side reasonably well,
page 2-31. With or without occupants.
http://www.nasa.gov/pdf/298870main_SP-2008-565.pdf
Page 2-129 shows the a almost intact middeck accommodation rack, very close
to the size and weight of an astronaut and seat. Pages 3-10, 3-11 are
interesting. "Nearly all seat fractures occurred at minimum thermal
cross-sectional areas (minimum thermal mass), away from any large heat sink
locations." The Aluminum really didn't perform well, essentially
melting/burning apart. Like flying in a burning wooden airplane.

--
Craig Fink
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