[Vwdiesel] Rabbit droppings --OT ----( The Discovery take off ? )

[Jim Arnott]

And my claim to authority: Inspector/Quality Engineer for all Orbiter 
Mid-Fuselages (My inspection stamp is somewhere on each one of 'em.)

Jim

Da RULES:

Akin's Laws of Spacecraft Design. Pay special attention to #36.

1. Engineering is done with numbers. Analysis without numbers is only 
an opinion.

2. To design a spacecraft right takes an infinite amount of effort. 
This is why it's a good idea to design them to operate when some things 
are wrong .

3. Design is an iterative process. The necessary number of iterations 
is one more than the number you have currently done. This is true at 
any point in time.

4. Your best design efforts will inevitably wind up being useless in 
the final design. Learn to live with the disappointment.

5. (Miller's Law) Three points determine a curve.

6. (Mar's Law) Everything is linear if plotted log-log with a fat magic 
marker.

7. At the start of any design effort, the person who most wants to be 
team leader is least likely to be capable of it.

8. In nature, the optimum is almost always in the middle somewhere. 
Distrust assertions that the optimum is at an extreme point.

9. Not having all the information you need is never a satisfactory 
excuse for not starting the analysis.

10. When in doubt, estimate. In an emergency, guess. But be sure to go 
back and clean up the mess when the real numbers come along.

11. Sometimes, the fastest way to get to the end is to throw everything 
out and start over.

12. There is never a single right solution. There are always multiple 
wrong ones, though.

13. Design is based on requirements. There's no justification for 
designing something one bit "better" than the requirements dictate.

14. (Edison's Law) "Better" is the enemy of "good".

15. (Shea's Law) The ability to improve a design occurs primarily at 
the interfaces. This is also the prime location for screwing it up.

16. The previous people who did a similar analysis did not have a 
direct pipeline to the wisdom of the ages. There is therefore no reason 
to believe their analysis over yours. There is especially no reason to 
present their analysis as yours.

17. The fact that an analysis appears in print has no relationship to 
the likelihood of its being correct.

18. Past experience is excellent for providing a reality check. Too 
much reality can doom an otherwise worthwhile design, though.

19. The odds are greatly against you being immensely smarter than 
everyone else in the field. If your analysis says your terminal 
velocity is twice the speed of light, you may have invented warp drive, 
but the chances are a lot better that you've screwed up.

20. A bad design with a good presentation is doomed eventually. A good 
design with a bad presentation is doomed immediately.

21. (Larrabee's Law) Half of everything you hear in a classroom is 
crap. Education is figuring out which half is which.

22. When in doubt, document. (Documentation requirements will reach a 
maximum shortly after the termination of a program.)

23. The schedule you develop will seem like a complete work of fiction 
up until the time your customer fires you for not meeting it.

24. It's called a "Work Breakdown Structure" because the Work remaining 
will grow until you have a Breakdown, unless you enforce some Structure 
on it.

25. (Bowden's Law) Following a testing failure, it's always possible to 
refine the analysis to show that you really had negative margins all 
along.

26. (Montemerlo's Law) Don't do nuthin' dumb.

27. (Varsi's Law) Schedules only move in one direction.

28. (Ranger's Law) There ain't no such thing as a free launch.

29. (von Tiesenhausen's Law of Program Management) To get an accurate 
estimate of final program requirements, multiply the initial time 
estimates by pi, and slide the decimal point on the cost estimates one 
place to the right.

30. (von Tiesenhausen's Law of Engineering Design) If you want to have 
a maximum effect on the design of a new engineering system, learn to 
draw. Engineers always wind up designing the vehicle to look like the 
initial artist's concept.

31. (Mo's Law of Evolutionary Development) You can't get to the moon by 
climbing successively taller trees.

32. (Atkin's Law of Demonstrations) When the hardware is working 
perfectly, the really important visitors don't show up.

33. (Patton's Law of Program Planning) A good plan violently executed 
now is better than a perfect plan next week.

34. (Roosevelt's Law of Task Planning) Do what you can, where you are, 
with what you have.

35. (de Saint-Exupery's Law of Design) A designer knows that he has 
achieved perfection not when there is nothing left to add, but when 
there is nothing left to take away.

36. Space is a completely unforgiving environment. If you screw up the 
engineering, somebody dies (and there's no partial credit because most 
of the analysis was right...)


On Friday, July 15, 2005, at 06:51 AM, Val Christian wrote:

> We all know that dumb things happen.  757s become gliders.  Vw diesels
> run out of fuel on the road.  It's all where our tolerances are.  If my
> lawnmower runs out of gas, or even throws a rod, it's normally of small
> consequence.  The same thing happening on my research aircraft, out 
> over
> a large body of cold cold water, with folks on board, and it's a very
> different situation.  It becomes more understandable when you 
> participate
> in the trade analysis.
>
> Val
>
>
>
>>
>>   Problem is the computer systems use those sensors to calculate burn 
>> times
>> and such.  More of a redundancy most likely as well as there being 
>> redundant
>> redundancies.  Kind of like complaining about two mags on your 
>> airplane
>> engine only you can't just coast in on your wings in the shuttle.  
>> You need
>> fuel to control the angle of decent and the allowable angle is pretty 
>> small.
>>
>>   Can it be done without all of that?  Sure it can.  Is it as easy, 
>> foolproof
>> and
>> safe?  No way!  Seems like overkill but it IS outerspace and yes 
>> simpler
>> would be less problematic but not as precise (they only had a 10 
>> minute
>> launch window).
>>   They have to make sure it goes flawlessly or the press will have a 
>> heyday!
>>      Loren


"We need a revolution."
"Keep saying that and we'll need a lawyer, assuming they let us have 
one."

Jan Steinman <www.Bytesmiths.com>