Maximum Rate Shuttle Launches

On Jun 12, 4:57 pm, Len wrote:
On Jun 12, 1:21 pm, Oren T wrote:



On Jun 12, 12:58 pm, "Ed Ruf (REPLY to E-MAIL IN SIG!)"

wrote:
On Mon, 11 Jun 2007 12:03:33 -0700, in sci.space.policy Len
wrote:

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.

I thought the SR-71 used its JP-7 fuel for hydraulic fluid? JP-7 isn't
anywhere near a solid even at winter temps in Hampton, VA where we have
several drums of if out back behind our facilities.
--
Ed Ruf )

A quick web search shows it had two hydraulic systems: one for the
engines which used the fuel as working fluid and another using
something solid at room temperature. Len suggests it may have been NaK
but a eutectic is liquid at STP (mp -12.6 C). Perhaps it was straight
sodium?

NaK would be solid on a cool day, but otherwise
liquid and more practical. Solid sounds more
interesting--and perhaps worth stretching a point
when people want to talk about an unusual plane?
:-)

Len

I should have added that Kelly Johnson was not
averse to turning a clever phrase such as: "We
get all of our thrust out of the inlet; the engine is
just a flow inducer." If you keep your books the
right way, this is actually true. The forces on the
B-70 engine mounts actually reversed at mach 3.

Len



Oren

On Jun 12, 1:21 pm, Oren T wrote:
On Jun 12, 12:58 pm, "Ed Ruf (REPLY to E-MAIL IN SIG!)"

wrote:
On Mon, 11 Jun 2007 12:03:33 -0700, in sci.space.policy Len
wrote:

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.

I thought the SR-71 used its JP-7 fuel for hydraulic fluid? JP-7 isn't
anywhere near a solid even at winter temps in Hampton, VA where we have
several drums of if out back behind our facilities.
--
Ed Ruf )

A quick web search shows it had two hydraulic systems: one for the
engines which used the fuel as working fluid and another using
something solid at room temperature. Len suggests it may have been NaK
but a eutectic is liquid at STP (mp -12.6 C). Perhaps it was straight
sodium?


Do you have an actual cite? (sight /pun)

The one source I could locate:
http://www.blackbirds.net/u2/c_bennett/bbird-03.html

" Another problem occurred when trying to pin-point leaks. With oil,
fuel, and hydraulic fluids being the same color, it was difficult to
actually see what was leaking. "

The same source, despite noting that the engines had to be heated in
order to thin the lubricating oil significantly fails to make any such
notation about the hydraulic system. The online version of the SR-71
flight manual (http://www.sr-71.org/blackbird/manual/) fails to
mention solid or unusually thick hydraulic fluid as well.

In fact, I could not find _any_ source that specified the hydraulic
fluid was a solid at room temperature. (Though I did find one that
claimed it was a powder.)

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

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

"Derek Lyons" wrote in message
...
"Greg D. Moore \(Strider\)" wrote:

After a year or so though, you start to hit into things like scheduled
maintenance (OMDP,)

That's not a problem for a sustained rate - because it's merely a
scheduling issue. It sounds like your write up was more based on 'how
long could a surge be maintained and how high would the surge rate
be'.

Partly yes. I didn't get to deep into how long a surge you could really
maintain etc.

I partly see the whole thing as a chicken and an egg problem.

Flights cost a lot, so you want to make sure you have as "full" a mission as
possible.

Which reduces the number of missions you might fly in a year. But of course
since fixed costs are just that and incremental costs are more variable, you
drive up the costs of individual flights, making them cost more, etc. :-)

In general though from my idle musing, 12-16 was definitely doable with some
investment (say a few billion) but did not require 10s of billions or
anything.



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

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



--
Greg Moore
SQL Server DBA Consulting Remote and Onsite available!
Email: sql (at) greenms.com http://www.greenms.com/sqlserver.html

Derek Lyons wrote:
John Doe wrote:
Would getting Kurs solve more than 70% of the problem with just the
integration with shuttle computers having to be done, or would
integrating Kurs with Shuttle end up costing more work than develooping
a new system from scratch for the shuttle ?

I suspect the latter.

I suspect so also. "Integration with the shuttle computers" is 90% of
the pain. Also, it's not just the shuttle that would have to be
upgraded; none of the APAS ports on ISS have the required passive Kurs
system installed.

Mike Combs wrote:
wrote in message
ups.com...
On Jun 11, 9:53?pm, "Jorge R. Frank" wrote:
Rand Simberg wrote:
Charles Talleyrand:
Can the shuttle fly with no one on board? Takeoff, dock, land, the
whole shebang?
No, but the ability to allow it to do so is trivial,
Perhaps for launch and landing. Not so for docking. That would be a
distinctly non-trivial upgrade.
soyuz could ferry trained pilots to handle final docking

Maybe Progress could be up-rated to take up a single pilot. It could
automatically dock with Station, then the pilot could hop over to the
unmanned Shuttle to dock it since automated docking is too complicated.

Hmmm.....

Hmmm... Progress has no heat shield. So what happens to the pilot in the
event of a launch abort? Or a failure to dock? If you're suggesting
up-rating the Progress to include a heat shield, don't bother. That
already exists. It's called Soyuz, silly.

And if the Progress docks to the station, just how does the pilot "hop
over" to the unmanned shuttle, since it hasn't docked yet? If your
intention was for him to hop back into the Progress, undock from the
station, then rendezvous and dock with the shuttle, then why would you
bother docking to the station first? That just wastes propellant and time.

Besides, you would have to equip the Progress/Soyuz with an APAS in
order to dock it with the shuttle. The Russian docking ports on ISS
aren't APAS. And the APAS ports on ISS don't support Kurs. So a
Soyuz/Progress modified to dock with a shuttle cannot dock with ISS. It
would have to be a "throwaway", and therefore would carry a higher price
than a Soyuz/Progress that was going to go to ISS anyway.

I know bbo hallreb isn't capable of thinking things through before he
posts, but I didn't think you'd fall into the same trap.

I know bbo hallreb isn't capable of thinking things through before he
posts, but I didn't think you'd fall into the same trap.- Hide quoted text -


talk about not thinking it thru, you add a adapter to one port that
allows a soyuz to dock with both ISS and shuttle. or modify a shuttle
permanetely to dock with soyuz.

shuttle remote control gets within a mile or two of ISS, soyuz already
at station flies over and pilots its docking.

I would hope that in the future, if nasa has a future things get a
standard for emergencies.

Remember the apollo 13 hassles where CO2 filters were different in CM
& LM?

ducttape special

Jeff Findley wrote:
"Charles Buckley" wrote in message
...
Henry Spencer wrote:
In article .com,
This has two big problems. First, it would greatly reduce the power of
Astronaut Office management, by taking a lot of the suspense and mystery
out of crew selection. And second, the astronauts hate having to let
non-astronauts into their flying clubhouses.
And even beyond those horrors would be a non-degreed warrant officer
from the US army flying as a payload specialist. What's the point
in 4 BS degrees, 3 MS degrees, and 2 PhD's on the resume then?

Obviously there's not any point in this. The current batch of astronauts
are, in general, vastly over qualified. For example, you don't need all
those degress to "fly" the RMS. Commercial crane operators arguably have
much the same job requirements, and often lift extremely expensive pieces of
hardware, but you'd be hard pressed to find people doing those jobs who have
multiple MS degrees and/or PhD's.


I know. I just used an actual specific example of Thomas J. Hennen.

http://www.jsc.nasa.gov/Bios/PS/hennen.html

As near as I can tell, this was about the smartest personel decision
ever to fly on Shuttle. They took someone from the end customer support
who was familiar with the technology. Fed him into the payload
development side of things so he was very familiar with the payload.
Then, about a year before he flew, he reported to NASA for flight and
shuttle training. I don't think NASA had any choice on this guy, at
all. He was specified by the DoD.

"Jorge R. Frank" wrote in message
...

I know bbo hallreb isn't capable of thinking things through before he
posts, but I didn't think you'd fall into the same trap.

Thanks. Actually, I was trying to use humor to question the assertion that
automated docking is exceedingly difficult by reminding everybody that
Progress does it routinely.

--


Regards,
Mike Combs
----------------------------------------------------------------------
By all that you hold dear on this good Earth
I bid you stand, Men of the West!
Aragorn

"Mike Combs" wrote in message
...
"Jorge R. Frank" wrote in message
...

I know bbo hallreb isn't capable of thinking things through before he
posts, but I didn't think you'd fall into the same trap.

Thanks. Actually, I was trying to use humor to question the assertion
that automated docking is exceedingly difficult by reminding everybody
that Progress does it routinely.

Don't you know automated rendezvous and docking is hard because *NASA* has
never done it? ;-)

Seriously though, it's not a trivial problem to solve, especially when you
consider that you need to integrate it into a vehicle that was never
designed to be completely automated in this way and you need to put in abort
modes that can handle ever conceivable contingency without damaging the
shuttle or the station (i.e. no RCS firings in the right magnitude/direction
to cause something like solar array damage).

Also, why bother to automate it on a vehicle that will always be manned?
It's kind of like expecting a fighter aircraft to be able to do mid-air
refueling while the autopilot is on and the pilot is sleeping.

Jeff
--
"They that can give up essential liberty to obtain a
little temporary safety deserve neither liberty nor
safety"
- B. Franklin, Bartlett's Familiar Quotations (1919)

Also, why bother to automate it on a vehicle that will always be
manned? It's kind of like expecting a fighter aircraft to be able
to do mid-air refueling while the autopilot is on and the pilot is
sleeping.

I wonder if perhaps fighter pilots might like to have that feature

It wouldn't surprise me at all to learn that someone is working on
something like that for UCAV's...at which point it is a small matter
of porting right?-)

rick jones
--
The glass is neither half-empty nor half-full. The glass has a leak.
The real question is "Can it be patched?"
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...