Re: Space funding (was Re: Hillary needs to quit)

pv+usenet@[EMAIL PROTECTED]
 (PV) wrote:

>Brian Thorn <bthorn64@[EMAIL PROTECTED]
> writes:
>>Technologically, no it isn't. There is not a better, high-performance
>>oxygen/hydrogen rocket engine than the Space Shuttle Main Engine (and
>>no one has figured out a better propellant combination.) The Shuttle's
>
>NASA disagrees, since they're sending out teams to aerospace junkyards
all
>over the planet, looking for J2 engine parts. They've lost a lot of the
>design plans needed to build them again, and also lost almost all of the
>institutional knowledge as to why they were built the way they were, and
>how individual parts were machined. It's the biggest loss of engineering
>knowledge of all time. That's NASA today.

Of course, that reveals vast ignorance of _why_ NASA is looking for J2
engine parts.

To put it simply, it's because the J2 can be air started and the SSME
cannot be.  Period.  It's cheaper to rebuild the J2 than to redesign
the SSME.  This is a function of design choices, not of technology.

>>Solid Rocket Booster, despite the Challenger Disaster, is by far the
>>best large solid-propellant rocket ever built, with by far the best
>>safety record. The Shuttle's External Tank is a spectacular
>
>SSRBs SUCK. Period. They can't be throttled, they can't be shut down, and
>they can't be aborted without jettisoning them and blowing them up. To
the
>devil with them. 

So what if they can't be throttled, shut down, or aborted? 

>>mass fraction that is still the best in the space industry. The
>>Shuttle's computers still operate software that is orders of magnitude
>>more reliable than standard commercial software. There is still no
>
>On hardware that's 20 years out of date

Actually, virtually all of the Shuttle control and navigation
electronics has been replaced in the last decade.  

On top of that, you could replace all the electronics on the Shuttle
with the latest vunderchips out of Intel or whoever - and you wouldn't
change the system performance one bit.  The Shuttle is a tightly bound
hardware _and_ software system with limits in many places.  The
performance of the Shuttle on ascent is dominated by SSME and SRB
design and by aerodynamics.  The performance of the Shuttle on orbit
is dominated by the size of the OMS and RCS engines and the precision
of their (mechanical!) throttles.  The performance on re-entry and
landing is dominated by aerodynamics.  Etc... Etc...

Changing the computers to something more 'modern' buys you nothing at
all.  Concern over the age of the electronics is a sign of ignorance.

>it's not all that reliable. They've had a lot of time to find bugs, but
>early on computer problems were a common source of scrubs and countdown
>delays.

Fascinating - you claim they aren't reliable, but the only examples
you care note are from twenty years and more ago.

>>other operational reusable thermal protection system... Shuttle's
>>tiles are in a league of their own.
>
>Not any more they're not. And they're so freaking fragile that you can
>damage one by throwing a piece of foam at them

No, you can't damage them by 'throwing' a piece of foam at them.  You
can damage them by hitting them with the equivalent energy of a small
artillery shell however.  (You are aware of the velocity with which
the foam hits the tiles are you not?)

>>Especially since it is the vehicle responsible for 70% of the people
>>who have ever travelled into space and has done so with a failure
>>record statistically no worse than its chief rival, Russia's Soyuz.
>
>At many times the cost.

Here in the real world greater performance and greater capacity almost
always implies greater cost.

D.
-- 
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL