In article ,
says...

On Sunday, January 29, 2017 at 8:48:04 AM UTC-5, Jeff Findley wrote:

To be fair, middle level shuttle managers were put in a bad spot by the
higher ups. They had to manage what amounted to an experimental program
and pretend it was an "operational" program after five test flights.
The higher ups put a huge amount of pressure on middle management to
increase the flight rate. This created the management culture of "if
we're going to ground it, you have to prove to me it will fail", which
doomed the Challenger crew.

Middle managers were also forced to do this with a budget which was
smaller than it should have been. An example of this was right before
Challenger there was a distinct lack of spare parts. They were pulling
parts from recently returned orbiters so they could be installed on
another orbiter which was being prepared to fly. Imagine if you had two
cars and had to pull the cylinder head from one and install it on the
other when you wanted to use it. Insane, right?

To begin with, the SRBs ought to have been replaced with reusable liquid
boosters, but that would have been *quite* expensive to develop (which
is why SLS is still using solids). Other improvements, like non-toxic
OMS/RCS propellants and replacing the APUs and hydraulics with
electrically operated actuators would have improved the turn-around time
and reduced the risks to ground crews.

It was an avoidable disaster, they should not have launched on such
a cold day, and that precipitated the failure of the O-rings.

Agreed that they should not have launched when it was so cold. But, the
fact is they shouldn't have been launching AT ALL. Prior flights showed
evidence of o-ring erosion. Those o-rings were never designed to come
into contact with hot combustion gases. The fact that this was
happening indicated a design flaw that needed to be fixed.

The SRB field joint design was quite simply an accident waiting to
happen. Even if Challenger had not launched on that cold morning, if
they continued to launch without a field joint redesign, we would have
eventually lost an orbiter. One huge contributing factor was the fact
that segments became "out of round" after flight and were often
difficult to get back into shape and reassemble. The fact is that the
shuttle should never have been flying with o-ring erosion taking place.

Columbia could have been saved; if they used ground based telescopes
to find the damage, then they would have had 2 weeks to come up with
a patch from either material on board or material sent up on an
expendable rocket, then EVAs to apply the patch. The ability to
patch would have been marginal, but they would have had a good shot
at a safe landing.

It is debatable if Columbia could have been saved. Yes, the consensus,
after the fact, is that military ground based telescopes should have
been used to attempt to assess the damage. Mounting a rescue mission
before the crew ran out of consumables would still have been quite
difficult, with no guarantee of success. Patching the hole would have
been problematic because it most likely was quite large and was on the
wing leading edge, which is one of the hottest parts of the orbiter on
reentry.

Their best bet for being saved would have been to launch the next
scheduled shuttle mission as a rescue mission with only a pilot and co-
pilot and bring back the crew on a known good shuttle. Ground crews
would have been working 24/7 to make this happen and the schedule would
have needed to be shortened as much as possible.

But again, the shuttle should not have been flying at all with ET foam
shedding. It was never designed to withstand foam impacts to the
orbiter's fragile TPS.

Notice the commonality? In both cases the shuttle was flying and
encountering anomalies which the designers never anticipated. But,
because this was supposed to be an "operational" system, standing down
to actually analyze and fix the problems was quite simply not allowed by
the culture at the time.

After both Challenger, also note that many other potential problems were
fixed. There were many issues that the shuttle was flying with that
could have caused loss of crew. for example, the landing steering and
braking systems were quite marginal before Challenger since the wheel
brakes in the main landing gear did double duty by using differential
braking to steer. During the grounding, they added nose wheel steering
and the "drag chute" to take *a lot* of load off the wheel brakes.

Jeff
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