Re: Instant Shuttle turnaround ?

"Damon Hill" <damon1SIX1@xxxxxxxxxxxxxx> wrote in message
news:Xns9B6967020EC64damon161attbicom@xxxxxxxxxxxx
John Doe <jdoe@xxxxxxx> wrote in
news:002281ec$0$12298$c3e8da3@xxxxxxxxxxxxxxxxx:

This is a rethorical question, so no need to spout insults about how
unrealistic, unsafe it would be. I am more interested in the raw
mechanics of it. (and a "one off" exploit, not doing the stuff below
all the time).

The SSMEs are normally pulled and subject to a detailed inspection;
this may require a partial disassembly. These engines have been tested
to multiple firings without inspection, but NASA is being conservative.
Yeah, a set of inspected SSMEs could be on standby to install, but
that'll take a few days; lots of leak checks are required, for example.


I have an email someplace that indicates that they're basically at the point
of flying I think 3-5 missions with minor inspections before a tear down.
So this may not be an issue.


The heat shield tiles apparently require detailed inspection, some
repairs, and "recaulking" of the gaps between the tiles; I think this
is "normal" but unavoidably essential maintenance that prevents a
fast turnaround because of the man-hours required.


This is probably a big one, but I believe they have a 'robot' that helps
quite a bit here also (at least in the inspection part)


I don't know about the hydrazine APUs and hydraulic systems; seems that
the thrusters and OMS should be good for a quick turnaround if there
were no problems on the previous flight. Most other systems not using
fluids should be good to go if there were no failures requiring analysis
and repairs--NASA needs to have a good reason to fly without redundant
systems.


The APUs and OMS systems are probably the longest poles in the tent.

Since the Shuttle's main mission is ISS assembly and support, with a lot
of planning and preparation between flights, there doesn't seem to be
a pressing need for fast turnarounds. Given that there are very few
other reasons to fly Shuttle, again a fast turnaround doesn't seem to be
essential.

If you're postulating an emergency situation, isn't a Shuttle stack on
standby or the ISS a 'safe haven" until a Shuttle can be prepared for
a rescue flight?

My guess is that a "fast turnaround" is going to require at least a few
days or even weeks; Shuttle was originally supposed to have a two-week
turnaround but that's never even remotely worked in practice.

I believe the fastest turn-around of an orbiter was between STS-83 and
STS-94

landed - April 8th 1997
launched - July 1st 1997


Would a "new generation" Shuttle have a shorter turnaround, if new or
improved systems were available? Probably, but it depends on the
individual systems--particularly the thermal protection system has been
very sensitive and requiring detailed inspection and maintenence. A
different type of technology seems essential for the TPS, perhaps a
whole new Shuttle design fundamentally different from the existing
system.

If I were building a Mark II shuttle, I'd focus on the engines, OMS/APU/RCS
subsystems and the toilet. (Folks left out the toilet!)

The TPS I'd work on improving, but at this point for something that large,
not sure how much you could improve it.

It's far better than it was, that's for sure.


There's no lack of proposed reusable spacecraft/launch systems, but I'm
guessing a couple more generations of engineering and development will
be required to get turnarounds remotely similar to routine airline
operations.

It'll happen when there's a need for it.

--Damon



--
Greg Moore
Ask me about lily, an RPI based CMC.


.

Relevant Pages

  • Re: Instant Shuttle turnaround ?
    ... The SSMEs are normally pulled and subject to a detailed inspection; ... fast turnaround because of the man-hours required. ... If you're postulating an emergency situation, isn't a Shuttle stack on ... very sensitive and requiring detailed inspection and maintenence. ...
    (sci.space.shuttle)
  • Shuttle Inspections
    ... Atlantis astronauts attached a boom to the shuttle's robotic arm and started an inspection for damage to the shuttle's wings and nose. ... This is part of the post-Columbia accident routine for shuttles, in which astronauts look for the type of heat shield cuts and tears that caused the fatal shuttle accident in 2003. ...
    (sci.space.shuttle)
  • Re: The ding in the tile
    ... Shuttle usually uses, ... seems it would be a great test for the repair putty ... so its the same foam problem that killed clumbia? ... It is getting further detailed inspection ...
    (sci.space.shuttle)
  • Re: RUSSIAN ASTROLOGER SUES NASA, TRIES TO STOP DEEP IMPACT MISSION
    ... >> Of course there was NO need for a spacewalk or inspection. ... Speculation is foresight. ... with the crew and shuttle and ultimately lost. ...
    (sci.physics)
  • Shuttle lifeboat, on-orbit inspection for Criticaility One failures
    ... If a shuttle gets sufficiently damaged that it can't ... NASA's current plan for what to do, in case a TPS failure is discovered ... only to ISS (presumably inspection would also be easier using vantage ... Having a lifeboat capability could conceivably allow ...
    (sci.space.tech)