🚀 go-pugleaf

In article <BxzLMF.5J6@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:


   In article <STEINLY.92Nov19135044@topaz.ucsc.edu> steinly@topaz.ucsc.edu (Steinn Sigurdsson) writes:
   >... the operation costs do seem quite optimistic, in
   >particular I'd have thought the early years operation would be higher
   >while ground support learned some maintenance procedures and
   >operational experience was developed on what needs inspection and
   >refurbishing between flights? I just don't see any way around that,
   >are the DCs really that much simpler?

   Wrong question.  There are two ways to go about this.  One is to assume
   that between-flights turnaround will be very complex, but it will get
   better if we look for ways to improve it.  The other is to assume that
   it will be simple, although a few complications may be found.  Oddly
   enough, only the second approach ever results in something simple and
   cheap.  You can always come up with reasons why complexity is needed,
   especially after you've already written the manuals and hired the staff.
   Simple systems do not evolve from complex ones.

   The right question is:  why should the DCs be much more complex than
   high-performance aircraft?

Intrinsically I see no reason why an orbital launcher should be
more complex than that - as a matter of practicality though there is the
fact that you have a lot of energy to be controlled in a very short
time - the SSME's power rating is a respectible fraction of US
capacity! Now, the DCs are not being designed on the margin, 
they have to be robust if they are not to be stripped down and
inspected every time. I guess my question really is whether they've
succeeded in reducing the number of parts _and_ gotten the reliability
of each part to the point where maintenance will be as low as claimed.
There is no intrinsic reason why it can't be done, but it is not clear
that the knowledge base to decide what is necessary refurbishment and
what is waste is there yet. Of course the only way to find out
is to fly the thing :-)

|  Steinn Sigurdsson	|I saw two shooting stars last night		|
|  Lick Observatory	|I wished on them but they were only satellites	|
| steinly@lick.ucsc.edu |Is it wrong to wish on space hardware?		|
| "standard disclaimer"	|I wish, I wish, I wish you'd care - B.B. 1983	|