Maximum Rate Shuttle Launches

On 11 Jun, 14:17, Fred J. McCall wrote:
Ian Parker wrote:

:On 11 Jun, 07:06, Fred J. McCall wrote:
:
: The original vision called for 40 launches a year (with 5 orbiters, I
: believe), with an assumption of simple ground operation.
:
: In actuality, they'd be hard pressed to manage 8 flights a year (with
: 4 orbiters).
:
: The only way to do better than 8-9 flights a year is use a different
: vehicle.
:
:
:All this was deducible during the DESIGN stage. Yet those who were "in
:the know" promised us cheap access to space. They knew all along that
:this was poppycock. Can you wonder that we do not believe everything
:that is trotted out now?
:

All those people are long retired and probably dead by now, Ian...

They are indeed, but the bureaucracy goes on. No, we don't want to
drag people out of retirement. History, even further back is relevant.
In the 1930s it was generally accepted in Europe that Bolshevism was a
Jewish conspiracy. The Eastern Europeans did not need much
encouragement from the Nazis to participate in the Holocaust. People
tend to believe what their leaders tell them even if it is palpable
nonsense and easily provable to be so.

Nowadays I think that it would be more difficult for NASA to pull a
fast one. This is simply because computer power is so cheap and lots
of people have versions of the NASA design software.


- Ian Parker


- Ian Parker

Ian Parker wrote:
This is simply because computer power is so cheap and lots
of people have versions of the NASA design software.

The "NASA design software" huh? You have no idea what you're talking
about.


--
Fear is the path to the dark side...
Fear leads to anger...
Anger leads to hate...
Hate leads to banjos...
Banjos lead to suffering!

Herb Schaltegger wrote:

:Ian Parker wrote:
:
: This is simply because computer power is so cheap and lots
: of people have versions of the NASA design software.
:
:
:The "NASA design software" huh? You have no idea what you're talking
:about.
:

It's Ian. What else is new?

One gets the feeling that Ian forgets that there are engineers
involved in designing all this stuff...


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn

On Jun 11, 5:05 am, (Henry Spencer) wrote:

If (dim) memory serves, the fundamental limit set by having only four
orbiters was thought to be (in post-Challenger hindsight) something like
15-20/year. That rate would require quite a few more facilities -- e.g.,
two or three more of the big simulators at JSC -- and a lot of money.

Can you tell us more about these big simulators? Are these flight
simulators needed to train pilots, or some other thing?

I would find it quite odd if the rate limiting item for shuttle
launches was pilot training. Not impossible, just suprising.

On Mon, 11 Jun 2007 09:12:58 -0700, in a place far, far away, Charles
Talleyrand made the phosphor on my monitor glow
in such a way as to indicate that:

On Jun 11, 5:05 am, (Henry Spencer) wrote:

If (dim) memory serves, the fundamental limit set by having only four
orbiters was thought to be (in post-Challenger hindsight) something like
15-20/year. That rate would require quite a few more facilities -- e.g.,
two or three more of the big simulators at JSC -- and a lot of money.

Can you tell us more about these big simulators? Are these flight
simulators needed to train pilots, or some other thing?

Training for mission and payload specialists, because many missions
were unique.

by now the system is locked into 4 or 5 launches per year max.

over the years staffing has been cut a lot, spare parts in short
supply, fewer orbiters, rebuilds done by palmdale now done at KSC by
regular workers. Any thing being discontinued gets less money and
support.

Of course I would like to see the shuttle continue flying as a
unmanned cargo vehicle.

this would allow station completion flights with no risk of crew
deaths.

gut lots of life support stuff and things from crew cabin like no
longer needed seats to increase cargo weight capacity.

On Jun 11, 7:10 am, Ian Parker wrote:
.....snip,,,,,,

All this was deducible during the DESIGN stage. Yet those who were "in
the know" promised us cheap access to space. They knew all along that
this was poppycock. Can you wonder that we do not believe everything
that is trotted out now?

- Ian Parker

Ah yes. And so was the impossibility of fulfilling
cost goals--to anyone who was both competent and
honest.

This would be considered criminal behavior for a
public corporation. But taxpayer supported bureaurcracies
appear to be allowed to live by different rules and standards.

Len

On 11 Jun, 15:22, Herb Schaltegger wrote:
Ian Parker wrote:
This is simply because computer power is so cheap and lots
of people have versions of the NASA design software.

The "NASA design software" huh? You have no idea what you're talking
about.

What I am talking about specifically are aerodynamic simulation. You
can put a shape in and know more or less exacly how it will behave.
The A380 was designed in this way and all the results were within 2%
of nominal. When the Shuttle was built everyone who did not have what
were then supercomputers simply stuck their fingers into the air.

A similar situation holds with regard to engine technology. One can
fairly easilt find out what the stresses in the engine will be and see
if the figures add up.

Yes enginers design spacecraft. What I am saying is that one you have
a design you can get a pretty good idea of how it is going to work. Of
course if the design is secret .....

In one thread the idea of having competitions was raised. This is a
very sound principle. We said maintain a car in telepresence with a
2.5 sec delay. With 3GHz and 1 GB RAM being pretty universal on new
reasonably high end PCs we are at the point where we can give some
pretty heavy duty software to competitors and let them attempt to do
some designing. If people have their pet theories we could prove or
disprove them relatively simply.

Also please remember that the basic PC is far more powerful than the
"supercomputers" that helped design the Shuttle. 1GB 3GHz what
computer got anywhere near those specifications?

One other aspect of competition. ProEngineer has a JLink interface. If
NASA managed to sort out licenses this could be given to bright high
school kids and undergraduates. A lunar robot fabricator could be
designed and tested without bending metal.


- Ian Parker

On Jun 11, 6:05 am, (Henry Spencer) wrote:
,,,,snip,,,,

Note that the post-Challenger flight rate was substantially higher than it
is today -- I think it was 8/year when everything went right. The later
reductions were for financial reasons, not because there is any deep
obstacle to the higher rate.

Economics considerations are usually the limiting
factor for a lot of things that are blamed on tough
technology. As I understand it, even a complicated
beast like the SR-71--with hydraulic "fluid" that was
solid at room temperature--was flown twice in the
same day. IIRC, they only did it once, because of
cost considerations--not techinical difficulties.

Len

--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

Ian Parker wrote:
On 11 Jun, 15:22, Herb Schaltegger wrote:
Ian Parker wrote:
This is simply because computer power is so cheap and lots
of people have versions of the NASA design software.
The "NASA design software" huh? You have no idea what you're talking
about.

What I am talking about specifically are aerodynamic simulation. You
can put a shape in and know more or less exacly how it will behave.

Subsonic aerodynamics is pretty straightforward. Remember, planes have
been designed with sliderules, for Christ's sake. Hypersonic
aerodynamics are NOT simple and CFD doesn't get it right nearly as often
as you think it will. But I'm sure you know that already, right?

*waits expectantly*

(snipped the rest of technobabble)

You need to get an engineering degree if you haven't already, or brush
up on all the stuff you forgot otherwise. Then actually design
spacecraft and spacecraft systems for awhile so you can gain a few clues.

--
Fear is the path to the dark side...
Fear leads to anger...
Anger leads to hate...
Hate leads to banjos...
Banjos lead to suffering!