Shuttle/ISS extended?

Brian Thorn wrote:


That's not true. SSME is very expensive primarily because not many had
to be built,

The SSME is very expensive because it used a very complex design to be
both reusable and give max isp.

being a reusable engine. Higher production rates should
cut the unit cost considerably. SSME will always be more expensive
than RS-68, but that higher price buys you a lighter, smaller,
regeneratively-cooled engine with better thrust/weight and much better
ISp, all of which buys you a smaller, lighter SDLV than a comparable
RS-68 SDLV (look at the Goliath that Ares V became once it dropped
SSME. Now they're reconsidering that switch.)

While it may be possible to "de-rate" the SSME into a expendable form
that still preserves the same isp, I get a feeling that this will be
around as cheap and fast as how we were going to use a "stock" SRB for
the Ares 1 first stage... by the time you get done (and this goes for
J-2X also) you will have spent almost as much money as if you had
developed a whole new engine.
RS-68 is already in production and it works just fine and was designed
for low cost manufacture, as it was intended to be expendable right from
the word go. It also generates more thrust than the SSME (650,000 lb at
SL, vs the SSME's 409,000 lb.) so you need fewer engines to get the same
amount of thrust, which ups overall launch vehicle reliability.




In fact this could end up costing more per flight than the Shuttle - as
any savings in inspection and refurbishment after every flight will be
eaten up by the loss of the cargo pod and the engines.


But the payload is so much greater than Shuttle's that it's highly
unlikely to be more expensive per flight than Shuttle.


Yeah, but again, what do you need all that payload for? Everyone is
always yapping about how we killed the Saturn V, without realizing that
it was _so_ capable that there were only a few missions that it made any
sense to use it on.
You don't fly 747's on short city-to-city hops with 25 people on board,
or go out to get groceries in a 18 wheeler.


The other problem is that once the ISS is decommissioned, the only other
use for this booster will be Moon missions or building another space
station, as it's too big for much else,


That's true of Orion, as well. Which is exactly why NASA pitched
Return to the Moon and not Mars First.


I think when all is said and done, they will get neither.
Considering what a cocked-up mess (both financially and politically) the
ISS turned out to be, it's going to be a mighty long time before we see
a large space station again after it is decommissioned.

Pat

Brian Thorn wrote:
Delta IV-Heavy is actually the runner-up, not Ariane V. If built,
Atlas V-Heavy and potential Delta IV-Heavy upgrades would exceed
Shuttle's payload capacity.

LEO payload capacity:

Shuttle: 55,000 lbs.
Delta IV-Heavy: 50,000 lbs.
Ariane V: 46,000 lbs.
Atlas V 551: 44,500 lbs.
Proton: 44,100 lbs.


They've got much-modified Super Delta IV concepts that are in the Saturn
V catagory as far as payload goes.

Pat

In sci.space.history Pat Flannery wrote:
You don't fly 747's on short city-to-city hops with 25 people on board,

Well, perhaps on a bad day for an airline in Japan

http://en.wikipedia.org/wiki/Boeing_747

" In Japan, 747s on domestic routes are configured to carry close to
the maximum passenger capacity.[69]"

....

69 ^ Wallace, James. "A380 buyer keeps mum about possible luxuries
aboard cruise ship of the skies." Seattle Post-Intelligencer, January
24, 2005. Retrieved: December 13, 2007.

http://www.seattlepi.com/business/20...nterior24.html

"At the opposite end of the luxury spectrum is what All Nippon and
Japan Airlines have done to a few of their 747-400s for high-density
domestic routes in Japan.

They carry nearly 600 passengers in one class."

rick jones
--
Wisdom Teeth are impacted, people are affected by the effects of events.
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...

On Wed, 29 Jul 2009 19:26:14 -0500, Pat Flannery
wrote:

The SSME is very expensive because it used a very complex design to be
both reusable and give max isp.

You think building only one or two a year doesn't drive up the cost?

While it may be possible to "de-rate" the SSME into a expendable form

Why? No de-rating is needed. In fact, you can probably run it at 109%
since you'll never fly the thing again (the SSME can do so for aborts
as-is.)

I get a feeling that this will be
around as cheap and fast as how we were going to use a "stock" SRB for
the Ares 1 first stage...

Which was paired with an upper stage using SSME. SSME was dropped and
the first stage had to stretch. That SSME deletion was because it was
difficult to make the SSME air-startable (and nearly impossible for
re-start, which ruined Constellation's commonality concept between
Ares I and Ares V) not because the SSME was too expensive. For first
stage applications on Ares V, Not-Shuttle-C, and Jupiter, SSME is
actually the best option as it lets the rest of the rocket be smaller,
offsetting the higher cost for the most part, and totally eliminating
development cost (RS-68 will need a regenerative nozzle if you want to
put four or five of them on a rocket.)

by the time you get done (and this goes for
J-2X also) you will have spent almost as much money as if you had
developed a whole new engine.

No, you spend zero dollars. Use the off-the-shelf SSME, which has
worked superbly since the new turbopumps were introduced a decade ago.
We have a stockpile of them (20 or so upon Shuttle retirement) which
is enough engines for the first five or six Jupiter or Not-Shuttle-C
flights. That's 20 RS-68s we don't have to buy in the "money is
incredibly tight" early years.

RS-68 is already in production and it works just fine and was designed
for low cost manufacture, as it was intended to be expendable right from
the word go.

Base heating issues mean it will need a new nozzle, among other
changes, for a multi-engine core booster. The ablative cooling can't
handle the heat from all those engines right next to two SRBs. That's
among the many reasons the Ares V teams is reconsidering SSME. And
Ares V now is baselined with 6 RS-68s compared to 5 SSMEs. So now we
have six engines in the core instead of five, and those six engines
have their own new development program (regenerative cooling) to pay
for. How much time and treasure are we really saving here?

It also generates more thrust than the SSME (650,000 lb at
SL, vs the SSME's 409,000 lb.) so you need fewer engines to get the same
amount of thrust, which ups overall launch vehicle reliability.

You don't need the same amount of thrust. Look how much bigger (not
smaller) Ares V got when they switched from SSME to RS-68. It grew
wider and taller (now scraping the ceiling of the VAB), and they had
to upgrade to 5, and even 5 1/2 segment SRBs (now needing a new
Crawler and Crawlerway to handle the weight.) All this to save a few
million on the engine! Off-the-shelf SSME enables a smaller core and
off-the-shelf SRBs. Step right up, no waiting.

But the payload is so much greater than Shuttle's that it's highly
unlikely to be more expensive per flight than Shuttle.

Yeah, but again, what do you need all that payload for?

Better to have and not need than to need and not have. For the here
and now, we have to plan for the stated mission: return to the moon by
2020 and then move on to "Mars and beyond" at some unspecified date in
the future. Bush and Obama and two Congresses have all endorsed that
goal. So we have to ask what's the best launch method. Right now, I'd
say Delta IV-Heavy is. But we also know full well that any plan that
goes to the Hill saying "we're killing Shuttle infrastructure and
laying off the bulk of the workforce" will be dead on arrival. Simply
looking at COTS and EELV options has already resulted in an
influential Senator cutting off the extra funding NASA got from the
stimulus bill. Why fight a battle we can't win? That leaves
Shuttle-derived, and I think Jupiter with SSME is the best option,
with Not-Shuttle-C with SSME a close second. The RS-68-powered options
drive up size and infrastructure costs.

You don't fly 747's on short city-to-city hops with 25 people on board,
or go out to get groceries in a 18 wheeler.

No, but you don't deliver gas to a gas station one 5-gallon jug at a
time, either.

That's true of Orion, as well. Which is exactly why NASA pitched
Return to the Moon and not Mars First.

I think when all is said and done, they will get neither.

On an EELV or Falcon-based infrastructure, absolutely, there's no
chance whatsoever. But if we have a Shuttle-derived infrastructure, at
least we have all the pieces we need in service. You don't have to beg
Congress for billions for a new launcher. There would be, as a
previous President said, "a sporting chance." Let's not cut off that
possibility today.

Considering what a cocked-up mess (both financially and politically) the
ISS turned out to be, it's going to be a mighty long time before we see
a large space station again after it is decommissioned.

I think we'll see one within 20 years, but it will be commercial. But
even given the Shuttle and ISS misfires, two Presidents and two
Congresses have been supportive (albeit lukewarmly) of the return to
the moon goal. Clearly, politicians have not yet abandoned hope that
NASA can pull of a large space program. We just need someone (the
Augustine Commission) to force NASA to make a course correction or
two. Now.

Brian

On Wed, 29 Jul 2009 19:29:17 -0500, Pat Flannery
wrote:

LEO payload capacity:

Shuttle: 55,000 lbs.
Delta IV-Heavy: 50,000 lbs.
Ariane V: 46,000 lbs.
Atlas V 551: 44,500 lbs.
Proton: 44,100 lbs.


They've got much-modified Super Delta IV concepts that are in the Saturn
V catagory as far as payload goes.

Yeah, but those beasts need an all-new infrastructure (actually LC-39)
so I think they're much less realistic than upgraded Delta IV or the
available-upon-request Atlas V-Heavy.

Brian

Brian Thorn wrote:
On Wed, 29 Jul 2009 16:22:32 +1000, Sylvia Else
wrote:

Never has though, has it?

Many times. Twenty-five Spacelab missions (20,000 lbs. or so each),
fifteen SpaceHab flights as standalone research and supplementary
cargo to Mir and ISS, eight MPLM cargo flights to ISS, LDEF, Palapa
and Westar, European Retrievable Carrier, Japan's Space Flying Unit,
and numerous small satellites launched and recovered on the same
mission (SPAS, SPARTAN, Wake Shield Facility) although none of them
were particularly large.

I was thinking in terms of objects that hadn't been taken up in the same
mission. Maybe there have been a few.

But I stand by my position that it would now be considered too
dangerous. At least unless it could be achieved concurrent with some
other mission. Sending men up just to retrieve hardware that could
otherwise just be rebuilt amounts to exposing them to a 1 in 60 or so
risk of death just to save money.

Sylvia.

"Pat Flannery" wrote in message
dakotatelephone...
http://www.nytimes.com/2009/07/29/sc...29shuttle.html

"Another possibility would be to fly one or two shuttle missions through 2014,
Dr. Ride said, but reviving the manufacturing lines used for the shuttle would
make sense only if NASA canceled its plans for its next-generation rockets and
switched to a shuttle-derived design"

Anyone see some handwriting on the wall here?


Only in the space business can the former head of the
biggest contractor be put in charge of the 'review'.
And not give anyone the least amount of concern.

The writing on the wall is simply this, do you have any idea
how big our budget deficits are going to be for the next
five years or so? I mean unless NASA claims they can
....oh...say...Save the World...will they be getting any
more money to speak of.

Just think ....'stretch it out, and make it do less.'
Just like the lasts couple of generations.

The goal is the thing. Not where you want to go, but
what problems you intend to fix. The mathematically
ideal goal would simply find where /two things/ converge.

One, NASA's potential capabilities.
Two, the world's greatest problems.

Where do they converge?????????????????????????????

Can't anyone here comprehend the simplicity and validity
of this logic?

The two converge on a solar power station located somewhere
between the freaking Sun and Earth orbit.

You wanna save NASA, then save the damn world.
Else nothing has a future, so what's the point of any
smaller goal?

We're only decades away from a global warming induced
ice age, which means humanity will have to wait some
one hundred thousand years to see if it can do better
than this current short inter-glacial go-round.

Scroll down to fig 5, unless life stabilizes the atmosphere and soon
we're headed back into a deep freeze.
http://muller.lbl.gov/pages/IceAgeBo...f_climate.html

But if we can manage our biosphere, and slow the rate of
change, then Earth might instead see an end to ice ages
altogether. As life will have become the larger controlling
force than orbital mechanics for our biosphere. And humanity can
enjoy a continued and lengthy existence where any 'wonder'
at all becomes possible, if not the most probable.

We're at the critical or transition point between two starkly
different global futures. And we're making the wrong choice.
Another cold war, this time with the Chinese, instead of a new
clean and abundant energy source.



Jonathan


s







Pat

Greg D. Moore (Strider) wrote:
"Pat Flannery" wrote in message
news

Greg D. Moore (Strider) wrote:
However it's brought back every Spacelab mission it's flown.

I don't know if those count though, as they were never released on-orbit
and then retrieved later, like other things were.
Does anyone know if they ever picked up a military payload and returned
that to Earth?

The question though was concerning what it had returned, not what it had
returned it didn't start with.

Well, actually, I was thinking of the latter. The issue relates to
missions that require something like the shuttle orbiter, because they
couldn't be achieved using throwaway hardware.

Sylvia.

Pat Flannery wrote:


Sylvia Else wrote:

Surely, no one in their right mind would think that a shuttle derived
design made sense. If the shuttle proved anything, it was that a
fragile hypersonic glider with a long hot period during descent for
the sake of a high cross range and once round abort is not the way to go.

I think the idea is to ditch the wings and make it a disposable cargo
pod with a reentry capsule atop it.

Well maybe, but the point about using it to return large payloads to
Earth would suggest that the derivation included some sort of reusable
orbiter.

Sylvia.

On Thu, 30 Jul 2009 12:45:19 +1000, Sylvia Else
wrote:


I was thinking in terms of objects that hadn't been taken up in the same
mission. Maybe there have been a few.

LDEF, Palapa, Westar, and SFU.

But I stand by my position that it would now be considered too
dangerous.

You mean like how the next Shuttle mission (launching Aug 25 or so)
will be doing it? Its taking up an MPLM loaded to the brim with cargo,
which will be berthed to the Station, unloaded, filled up with things
to bring back, and then loaded back in the Shuttle for the return
trip. This is an important capability of Shuttle that will be sorely
missed once the Shuttle is retired.

At least unless it could be achieved concurrent with some
other mission. Sending men up just to retrieve hardware that could
otherwise just be rebuilt amounts to exposing them to a 1 in 60 or so
risk of death just to save money.

True, they won't send up a Shuttle to pick up something already in
orbit, the risk and cost are too great. But that doesn't mean that the
Shuttle's return payload capability is unnecessary. In fact, we are
losing it just when we'll need it the most. The Shuttles and MPLMs
return with broken hardware from the Space Station (notably the
Control Moment Gyros, too big to be returned by anything else),
allowing engineers to thoroughly examine them and hopefully make
improvements to the next one on the production line or design better
versions next time, so in that respect the risk may well be
worthwhile. There was also a lot of science planned for the Space
Station that would have sent results home using the Shuttle's large
return payload capability. That's gone after 2010.

Brian