The 100/10/1 Rule.

"Danny Deger" wrote in message
...

"Reunite Gondwanaland (Mary Shafer)" wrote in
message ...
On Sun, 04 Mar 2007 20:46:23 -0600, kT wrote:

However, one can argue that the expendable SSTO approach puts almost an
order of magnitude more mass into orbit, which is what I am suggesting.

Has anyone ever put anything into orbit with a single stage? I know
we've managed SSTS, Single Stage To Space, but I don't think we've
managed SSTO.

I don't think so. SSTO requires engines for efficent than we have and
requires fuel tanks lighter than we have. Both of these technologies need
to be developed to make a SSTO space craft. NASA tried to develop these
technologies a few year ago and failed in both. I don't know if there is
even a concept out there to make SSTO possible.

I stand corrected on this. An expendable SSTO is very feasible. The X-33
had problems in large part because it also was attempting to do an
atmospheric entry. The entry requirement added a lot of mass to the system.

Danny Deger

On Thu, 8 Mar 2007 09:18:31 -0600, Danny Deger wrote
(in article ):

I stand corrected on this. An expendable SSTO is very feasible.

But doesn't really serve much purpose - staging is a very mature technology
and allows huge improvements in upmass.

--
You can run on for a long time,
Sooner or later, God'll cut you down.
~Johnny Cash

Herb Schaltegger wrote:

On Thu, 8 Mar 2007 09:18:31 -0600, Danny Deger wrote
(in article ):

I stand corrected on this. An expendable SSTO is very feasible.

But doesn't really serve much purpose - staging is a very mature technology
and allows huge improvements in upmass.

And we are all so grateful for the astronomical increase in costs
associated with staging. All those engines, so little time.

--
Get A Free Orbiter Space Flight Simulator :
http://orbit.medphys.ucl.ac.uk/orbit.html

On Thu, 8 Mar 2007 09:40:58 -0600, kT wrote
(in article ):

And we are all so grateful for the astronomical increase in costs
associated with staging. All those engines, so little time.

The "astronomical costs" of hardware are insignificant. The real expense is
the payload, which benefits greatly from being allowed to be bigger than a
grapefruit and mass more than 100 kilograms.

--
You can run on for a long time,
Sooner or later, God'll cut you down.
~Johnny Cash

Herb Schaltegger wrote:

On Thu, 8 Mar 2007 09:40:58 -0600, kT wrote
(in article ):

And we are all so grateful for the astronomical increase in costs
associated with staging. All those engines, so little time.

The "astronomical costs" of hardware are insignificant.

No wonder space has been so thoroughly colonized already then.

Good job people, kudos all around.

--
Get A Free Orbiter Space Flight Simulator :
http://orbit.medphys.ucl.ac.uk/orbit.html

On Thu, 8 Mar 2007 10:37:27 -0600, kT wrote
(in article ):

Herb Schaltegger wrote:

On Thu, 8 Mar 2007 09:40:58 -0600, kT wrote
(in article ):

And we are all so grateful for the astronomical increase in costs
associated with staging. All those engines, so little time.

The "astronomical costs" of hardware are insignificant.

No wonder space has been so thoroughly colonized already then.

You act as if colonization is a self-evident goal of spaceflight.

Bwahahahahahahahahaa!

Good job people, kudos all around.

Get your head out of your ass and realize that money makes the world go
round. And satellites around the world, for that matter.

--
You can run on for a long time,
Sooner or later, God'll cut you down.
~Johnny Cash

Herb Schaltegger wrote:

Bwahahahahahahahahaa!

Get your head out of your ass and realize that money makes the world go
round.

And apparently you've got it to burn. Don't worry, you can print more.

Gosh, and I thought we were dealing with mathematics and physics here.

And satellites around the world, for that matter.

The crackpots are out tonight.

--
Get A Free Orbiter Space Flight Simulator :
http://orbit.medphys.ucl.ac.uk/orbit.html

On Thu, 8 Mar 2007 11:19:55 -0600, kT wrote
(in article ):

Herb Schaltegger wrote:

Bwahahahahahahahahaa!

Get your head out of your ass and realize that money makes the world go
round.

And apparently you've got it to burn. Don't worry, you can print more.

How does a notional tiny-payload expendable SSTO make any kind of economic
sense?

Gosh, and I thought we were dealing with mathematics and physics here.

Gosh, see above.

And satellites around the world, for that matter.

The crackpots are out tonight.

Well I'd agree, since it's still morning in most of the U.S. when I post this
(and early afternoon for the rest of the western hemisphere). Not even
remotely close to "tonight", crackpot.



--
You can run on for a long time,
Sooner or later, God'll cut you down.
~Johnny Cash

"Pat Flannery" wrote in message
...

Jeff Findley wrote:
False, especailly for an expendable SSTO. An expendable SSTO isn't all
that hard to do, it's just that no one has tried. The "performance uber
alles" philosophy of your typical aerospace engineer makes them *really*
want to drop some of the heavy bits on the way up, even if it adds
complexity and cost to the design because they always think that the
performance gained is worth the added cost.

You can see the germ of Atlas in North Amercian Aviation's HATV design
from 1946: http://history.nasa.gov/SP-4202/p1-10.jpg
You can just see an engineer looking at that, and thinking: "Now , if we
could jettison the eight small motors once a lot of the fuel was burnt..."

Kind of, sort of, if you moved as much as possible into the part you drop.
As Henry pointed out, Atlas dropped the tank pressurization system with the
booster engines. In the HATV design, that system isn't very close to the
eight small motors.

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)

"Danny Deger" wrote in message
...
I stand corrected on this. An expendable SSTO is very feasible. The X-33
had problems in large part because it also was attempting to do an
atmospheric entry. The entry requirement added a lot of mass to the
system.

No, X-33 had problems because it was the most technologically challenging
design out of the three proposals (all three proposals had to deal with
re-entry) *and* there was no real incentive for NASA or the contractor, to
actually make it fly. Note that both the contractor *and* NASA already had
operational launch vehicle programs.

NASA "learned" the wrong lessons from X-33.

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)