The 100/10/1 Rule.

Sylvia Else wrote:

It's all about the overall cost of putting payload into orbit. A TSTO
would presumably give a better payload ratio, but with extra complexity
(equals dollars) both in the vehicles themselves, and in handling the
vehicles when they're in use. So the net cost per kg in orbit may be
higher for a TSTO than for an SSTO despite the higher payload ratio.

An airliner style operation using a single vehicle per mission is very
attractive if it's achievable. After the vehicle lands, you just refuel
it, put in the next mission's payload and you're ready to launch again.

And I posit we must approach that SSTO RLV launch scenario
incrementally. The 100/10/1 puts the masses involved in perspective.

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.

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

kT wrote:

Sylvia Else wrote:

It's all about the overall cost of putting payload into orbit. A TSTO
would presumably give a better payload ratio, but with extra
complexity (equals dollars) both in the vehicles themselves, and in
handling the vehicles when they're in use. So the net cost per kg in
orbit may be higher for a TSTO than for an SSTO despite the higher
payload ratio.

An airliner style operation using a single vehicle per mission is very
attractive if it's achievable. After the vehicle lands, you just
refuel it, put in the next mission's payload and you're ready to
launch again.


And I posit we must approach that SSTO RLV launch scenario
incrementally. The 100/10/1 puts the masses involved in perspective.

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.


Only because you're deeming that the spacecraft hardware in orbit is
part of the payload. That's fine if you have someone who wants that
payload in orbit, but most launches involve other kinds of payload.

Sylvia.

On 4 Mar 2007 08:29:52 -0800, "Frogwatch"
wrote:

On Mar 4, 11:28 am, "Frogwatch" wrote:
On Mar 2, 4:42 pm, kT wrote:

I've been simulating single stage to orbit (SSTO) launch to low earth
orbit (LEO) in orbiter space flight simulator for a little while now.

In order to increase this payload, the obvious solution is converting
the rocket itself into payload.

BTW, why ssto, wouldnt tsto give better payload ratio?

Certainly, but kT is playing some sort of game with SSTO.

SSTO itself is just an engineering challenge, not the most economical
way to achieve orbit. Most SSTO studies postulate a fully reusable
vehicle to achieve some level of economy, but the margins, payload
performance, and real costs just are not competitive. kT's
cannibalistic SSTO vehicle seems pointless.

Sylvia Else wrote:
kT wrote:

Sylvia Else wrote:

It's all about the overall cost of putting payload into orbit. A TSTO
would presumably give a better payload ratio, but with extra
complexity (equals dollars) both in the vehicles themselves, and in
handling the vehicles when they're in use. So the net cost per kg in
orbit may be higher for a TSTO than for an SSTO despite the higher
payload ratio.

An airliner style operation using a single vehicle per mission is
very attractive if it's achievable. After the vehicle lands, you just
refuel it, put in the next mission's payload and you're ready to
launch again.


And I posit we must approach that SSTO RLV launch scenario
incrementally. The 100/10/1 puts the masses involved in perspective.

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.


Only because you're deeming that the spacecraft hardware in orbit is
part of the payload. That's fine if you have someone who wants that
payload in orbit, but most launches involve other kinds of payload.

Then they can launch on little Dneprs for all I care, I want to colonize
space, and the 100/10/1 rule is the only way I know how. If I'm going to
be flying around in a large spaceship for any length of time, I want as
much fuel and hardware as I can get. By leveraging the 10/1 rule to our
advantage the material and infrastructure in orbit gets large very fast.

Plus, I can get the engines back, so it's sustainable, and it's an order
of magnitude less flights that it otherwise would have taken. Thus, it's
scalable and sustainable so things only get bigger and better over time.

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

Alan Jones wrote:

SSTO itself is just an engineering challenge, not the most economical
way to achieve orbit. Most SSTO studies postulate a fully reusable
vehicle to achieve some level of economy, but the margins, payload
performance, and real costs just are not competitive. kT's
cannibalistic SSTO vehicle seems pointless.


Although something close to it was once suggested:
http://www.geocities.com/atlas_missi...r_missions.htm
I had that model as a kid.

Pat

Alan Jones wrote:
On 4 Mar 2007 08:29:52 -0800, "Frogwatch"
wrote:

On Mar 4, 11:28 am, "Frogwatch" wrote:
On Mar 2, 4:42 pm, kT wrote:

I've been simulating single stage to orbit (SSTO) launch to low earth
orbit (LEO) in orbiter space flight simulator for a little while now.
In order to increase this payload, the obvious solution is converting
the rocket itself into payload.

BTW, why ssto, wouldnt tsto give better payload ratio?

Certainly, but kT is playing some sort of game with SSTO.

It's not a game, it's a fully qualified space simulator.

SSTO itself is just an engineering challenge, not the most economical
way to achieve orbit. Most SSTO studies postulate a fully reusable
vehicle to achieve some level of economy, but the margins, payload
performance, and real costs just are not competitive. kT's
cannibalistic SSTO vehicle seems pointless.

I'm not cannibalizing anything, I'm designing it all in from scratch.

Everything is used as is. At the most, it will require a space suit to
get into the hydrogen tank to seal the ports. All the the pressurization
hardware can be used as is. If anything, I'll be adding hardware to it.

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

Pat Flannery wrote:

Alan Jones wrote:

SSTO itself is just an engineering challenge, not the most economical
way to achieve orbit. Most SSTO studies postulate a fully reusable
vehicle to achieve some level of economy, but the margins, payload
performance, and real costs just are not competitive. kT's
cannibalistic SSTO vehicle seems pointless.

Although something close to it was once suggested:
http://www.geocities.com/atlas_missi...r_missions.htm
I had that model as a kid.

Something like that, but updated to 21st century design and engineering
sophistication, and using space shuttle main engines of course.

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

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.

Mary "Haven't thought about this for years"
--
Mary Shafer Retired aerospace research engineer
We didn't just do weird stuff at Dryden, we wrote reports about it.
or
Visit my new blog at http://thedigitalknitter.blogspot.com/

On Mon, 05 Mar 2007 14:10:19 -0800, in a place far, far away, "Reunite
Gondwanaland (Mary Shafer)" made the
phosphor on my monitor glow in such a way as to indicate that:

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.

The old Atlas could have come pretty close. With a small enough
payload, it might have been able to.

Rand Simberg wrote:
The old Atlas could have come pretty close. With a small enough
payload, it might have been able to.


That would be fun to figure out; the weight of the aft skirt and its
engines versus that of the LEO payload.
The Atlas H 1/2 stage weighed 8,038 lb according to Encyclopedia
Astronautica; payload to LEO is 8,000 pounds, so with a lightweight
aerodynamic nosecone, who knows?
You'd be able to strip some weight off of the 1/2 stage because it
wouldn't have to separate, so the plumbing could be simpler.
It'd be a mighty low orbit, but you might be able to do it.

Pat