The 100/10/1 Rule.

"Pat Flannery" wrote in message
...


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?

Hmm, and can you upgrade the engines at all?

Might gain you a bit more.

So.. what could you do with say:

200lbs
500lbs
1000lbs

I think the first 2 are basically "small sat" type things.

1000lbs, a bare minimum once around capsule?


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


--
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SQL Server DBA Consulting
sql (at) greenms.com http://www.greenms.com

Greg D. Moore (Strider) wrote:
Hmm, and can you upgrade the engines at all?

Might gain you a bit more.

So.. what could you do with say:

200lbs
500lbs
1000lbs

I think the first 2 are basically "small sat" type things.

1000lbs, a bare minimum once around capsule?


It really doesn't make any sense though.
Because of its size and low mass, the Atlas booster will destructively
reenter in fairly short order from air drag anyway, so you really
haven't gained anything by doing it this way.
It would make more sense to figure out how to recover the 1/2 stage
after jettison.
But the two engines in that were fairly cheap low-tech ones, so that
really doesn't make any sense either, considering the amount of payload
you'd lose from the weight of the recovery system.

Pat

Reunite Gondwanaland (Mary Shafer) wrote:
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"



Scott Lowther claimed a long time back that Thor could do it, but then
backed off that statement.
I wonder if Thor could, minus any payload?
I think the single stage Atlas conversion would be the most reasonable
choice.
It's almost going to have to be something using balloon tankage to get
the mass fraction to where it's good enough to do the job.

Pat

"Reunite Gondwanaland (Mary Shafer)" writes:

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 assume there's an implied "earth" before orbit there, since all the
lunar landing LMs' ascent stages were SSTO, albeit lunar.

In article ,
Reunite Gondwanaland (Mary Shafer) wrote:
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.

No actual SSTOs, yet. There have been several SSTO-capable expendable
rocket stages built, but nobody has ever thought it worthwhile to actually
fly one of them as an SSTO. The S-IC and the Titan II first stage were
both in the right ballpark, although both would need less engine thrust,
and at least the Titan stage would need throttleable engines. Mitch
Burnside Clapp's analysis said that straightforward Atlas and Delta
variants could do it too.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

In article ,
Pat Flannery wrote:
It's almost going to have to be something using balloon tankage to get
the mass fraction to where it's good enough to do the job.

Interestingly enough, both the Titan II first stage and the S-IC had lower
tank mass, in proportion to contents, than the Atlas E did. (Some of the
other Atlas variants may have done better, but I don't have numbers for
them handy. Atlas tank-wall thickness got dialed up and down to suit the
application.) Mind you, the Titan stage benefitted from higher propellant
densities, and the S-IC from sheer scale.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

"Greg D. Moore (Strider)" wrote in message
nk.net...
So.. what could you do with say:

200lbs
500lbs
1000lbs

I think the first 2 are basically "small sat" type things.

1000lbs, a bare minimum once around capsule?

This reminds me of some of the discussion that went on in sci.space about
16-17 years ago about the smallest rocket that could put either 1 oz or 1 kg
into orbit. It was the first time I'd heard of ring laser gyros. The
discussion veered off into how many model rocket engines would be needed. I
kept the printouts for several years.

Scott Hedrick wrote:
This reminds me of some of the discussion that went on in sci.space about
16-17 years ago about the smallest rocket that could put either 1 oz or 1 kg
into orbit. It was the first time I'd heard of ring laser gyros. The
discussion veered off into how many model rocket engines would be needed. I
kept the printouts for several years.



I can't find it now, but a few weeks back I stumbled on someone trying
to do that with a diminutive multistage rocket out on the web.
I think it uses pressure-fed hypergolic fuels, and is around 15 feet
long IIRC.

Pat

Henry Spencer wrote:

In article ,
Pat Flannery wrote:
It's almost going to have to be something using balloon tankage to get
the mass fraction to where it's good enough to do the job.

Interestingly enough, both the Titan II first stage and the S-IC had lower
tank mass, in proportion to contents, than the Atlas E did. (Some of the
other Atlas variants may have done better, but I don't have numbers for
them handy. Atlas tank-wall thickness got dialed up and down to suit the
application.) Mind you, the Titan stage benefitted from higher propellant
densities, and the S-IC from sheer scale.

Certainly a space shuttle main engine could do it with any decent
tankage. I want to do it. I'm going to do it. It shall be done.

--
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http://orbit.medphys.ucl.ac.uk/orbit.html

Pat Flannery wrote:


Scott Hedrick wrote:
This reminds me of some of the discussion that went on in sci.space
about 16-17 years ago about the smallest rocket that could put either
1 oz or 1 kg into orbit. It was the first time I'd heard of ring laser
gyros. The discussion veered off into how many model rocket engines
would be needed. I kept the printouts for several years.


I can't find it now, but a few weeks back I stumbled on someone trying
to do that with a diminutive multistage rocket out on the web.
I think it uses pressure-fed hypergolic fuels, and is around 15 feet
long IIRC.

Pat


I remember the thread Scott refers to. IIRC, there is an amateur
group out in CA that is using that as its baseline since the
supersonic milestone by amateurs has been met. Spaceflight is
the next amateur milestone.