JF Mezei wrote on Thu, 23 Aug 2018
14:18:13 -0400:

On 2018-08-23 06:40, Jeff Findley wrote:

During crew ingress, the launch vehicle isn't at all fueled.


If this is a recent concession by NASA, it would explain why they still
needed those ziplines etc to be installed at a time where they thought
pad crews and flight crews would be present at a time the stack was
loaded with fuel and LOX.


Well, no. I thought they were a silly idea when they did them for the
Shuttle. They're sillier now.


I believe one of the goals of the ziplines is to get people away from a
burning rocket, something which an elevator doesn't do. *unless elevator
shaft is fire/bomb proof).


Rockets don't 'burn'. They detonate. You're never going to have time
to unbutton the capsule, jump in a basket, and zip line to safety.
Capsule, basket, and all will be in a big ball of fire.


In a new scenario where fueling is done after pad crew has left, the
odds or catastropy may be lower but not nill (consider structural
failure, premature start of loading of fuel in a sequencce that causes
explosion etc etc.


The zip line deal was never for 'pad crew'. It was and is for vehicle
crew.


NASA and SPaceX have measures in place to prevent known problems. The
issue is problems that have not been preducted. (look at the explosion
because of loading superxooled fuel in the wrong sequence with Helium)


Yes, look at that explosion and imagine trying to evacuate the capsule
and zip line to safety in the midst of all that.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn