A Space & astronomy forum. SpaceBanter.com

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » SpaceBanter.com forum » Space Science » Space Station
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

The 100/10/1 Rule.



 
 
Thread Tools Display Modes
  #31  
Old March 6th 07, 03:41 PM posted to sci.space.history,sci.space.policy,sci.space.station,sci.space.shuttle
kT
external usenet poster
 
Posts: 5,032
Default The 100/10/1 Rule.

Pat Flannery wrote:

Henry Spencer wrote:
Addendum: And there have been several rediscoveries of the fact that if
you put six or seven SSMEs underneath an ET, even with generous
allowances
for things like thrust structure, it makes orbit with about the same
payload as the shuttle.


What about RS-68s?


You would be hard pressed to get an RS-68 to go single stage.

The T/W ratio is twice the SSME, and the Isp is lower.

Plus it's a ... ahem ... hard starter.

--
Get A Free Orbiter Space Flight Simulator :
http://orbit.medphys.ucl.ac.uk/orbit.html
Ads
  #32  
Old March 6th 07, 03:43 PM posted to sci.space.history,sci.space.policy,sci.space.station,sci.space.shuttle
kT
external usenet poster
 
Posts: 5,032
Default The 100/10/1 Rule.

Pat Flannery wrote:

Charles Buckley wrote:

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.



The article actually had a picture of the rocket; it was pretty
hilarious-looking.


I noticed that cool geocities site you posted immediately went over
bandwidth. How long do I have to wait for that to come back online?

Did anybody think to download any images off of it?

--
Get A Free Orbiter Space Flight Simulator :
http://orbit.medphys.ucl.ac.uk/orbit.html
  #33  
Old March 6th 07, 04:48 PM posted to sci.space.history,sci.space.policy,sci.space.station,sci.space.shuttle
Jan Vorbrüggen[_1_]
external usenet poster
 
Posts: 48
Default The 100/10/1 Rule.

You would be hard pressed to get an RS-68 to go single stage.
The T/W ratio is twice the SSME, and the Isp is lower.


Isn't the engine T/W somewhat irrelevant? You need a suitable mass fraction of
the whole stage to get to orbit, and the engine mass surely is only a small
fraction of the total dry weight.

Jan
  #34  
Old March 6th 07, 05:13 PM posted to sci.space.history,sci.space.policy,sci.space.station,sci.space.shuttle
kT
external usenet poster
 
Posts: 5,032
Default The 100/10/1 Rule.

Jan Vorbrüggen wrote:

You would be hard pressed to get an RS-68 to go single stage.
The T/W ratio is twice the SSME, and the Isp is lower.


Isn't the engine T/W somewhat irrelevant? You need a suitable mass
fraction of the whole stage to get to orbit, and the engine mass surely
is only a small fraction of the total dry weight.


You can easily simulate this in orbiter to first order approximation. I
just haven't bothered to do it yet, because the way it stands right now,
if I want to fly either the RS-68 or the RL-10, I can fly the Delta IV.

In my SSME based test vehicle, engine weight is 20%.

Everything that has mass is relevant to SSTO.

--
Get A Free Orbiter Space Flight Simulator :
http://orbit.medphys.ucl.ac.uk/orbit.html
  #35  
Old March 6th 07, 05:21 PM posted to sci.space.history,sci.space.policy,sci.space.station,sci.space.shuttle
kT
external usenet poster
 
Posts: 5,032
Default The 100/10/1 Rule.

kT wrote:

Jan Vorbrüggen wrote:

You would be hard pressed to get an RS-68 to go single stage.
The T/W ratio is twice the SSME, and the Isp is lower.


Isn't the engine T/W somewhat irrelevant? You need a suitable mass
fraction of the whole stage to get to orbit, and the engine mass
surely is only a small fraction of the total dry weight.


You can easily simulate this in orbiter to first order approximation. I
just haven't bothered to do it yet, because the way it stands right now,
if I want to fly either the RS-68 or the RL-10, I can fly the Delta IV.

In my SSME based test vehicle, engine weight is 20%.

Everything that has mass is relevant to SSTO.


Actually I mispoke, the RAW mass of the RS-68 is twice the SSME.

You're right T/W is somewhat less important here. I think it's in the 50
to 1 range.

--
Get A Free Orbiter Space Flight Simulator :
http://orbit.medphys.ucl.ac.uk/orbit.html
  #36  
Old March 7th 07, 03:06 AM posted to sci.space.history,sci.space.policy,sci.space.station,sci.space.shuttle
Joseph Nebus
external usenet poster
 
Posts: 306
Default The 100/10/1 Rule.

"Reunite Gondwanaland (Mary Shafer)" writes:

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.


Would you count the 1958 SCORE (Signal Communications Orbit
Relay Equipment), allowing that the Atlas B didn't shed a *whole*
stage on its ascent?

--
Joseph Nebus
------------------------------------------------------------------------------
Can we argue the definition of 'stage' until all comprehension
is lost and only nitpicking remains?
  #37  
Old March 7th 07, 05:16 AM posted to sci.space.history,sci.space.policy,sci.space.station,sci.space.shuttle
Henry Spencer
external usenet poster
 
Posts: 2,170
Default The 100/10/1 Rule.

In article ,
Joseph Nebus wrote:
Has anyone ever put anything into orbit with a single stage? ...


Would you count the 1958 SCORE (Signal Communications Orbit
Relay Equipment), allowing that the Atlas B didn't shed a *whole*
stage on its ascent?


Alas, realistically, the classical Atlas -- which launched the orbital
Mercury flights and several other things, in addition to SCORE -- has to
be deemed a two-stage vehicle for this purpose.

It didn't drop a whole stage, no, but it dropped most of the heavy parts
of one. (And some parts of the "upper stage", too -- notably, the entire
tank-pressurization system departed with the booster engines! The gas
left in the mostly-empty tanks was sufficient to keep them pressurized
thereafter, aided by hydrostatic head from high acceleration.)
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |
  #38  
Old March 7th 07, 05:20 AM posted to sci.space.history,sci.space.policy,sci.space.station,sci.space.shuttle
Henry Spencer
external usenet poster
 
Posts: 2,170
Default The 100/10/1 Rule.

In article ,
Pat Flannery wrote:
Addendum: And there have been several rediscoveries of the fact that if
you put six or seven SSMEs underneath an ET, even with generous allowances
for things like thrust structure, it makes orbit with about the same
payload as the shuttle.


What about RS-68s?


Haven't done the analysis, but my gut feeling is, not so good -- this is
one place where the RS-68's lower performance really does hurt.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |
  #39  
Old March 8th 07, 01:06 AM posted to sci.space.history,sci.space.policy,sci.space.station,sci.space.shuttle
Pat Flannery
external usenet poster
 
Posts: 18,466
Default The 100/10/1 Rule.



kT wrote:

I noticed that cool geocities site you posted immediately went over
bandwidth. How long do I have to wait for that to come back online?


I'm not sure which one you are referring to, but I think it's a daily
thing, isn't it?
Or is it monthly?
Rusty Barton's ICBM websites used to have that problem a lot, because
they were so well done.

Pat

  #40  
Old March 8th 07, 04:03 AM posted to sci.space.history,sci.space.policy,sci.space.station,sci.space.shuttle
Danny Deger
external usenet poster
 
Posts: 530
Default The 100/10/1 Rule.


"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.

Danny Deger


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/



 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
The 100/10/1 Rule. kT Space Shuttle 156 March 28th 07 03:25 AM
Going Forth to Rule the World Warhol Misc 0 May 22nd 06 05:19 PM
Is this like some kind of rule? Rich Amateur Astronomy 7 January 16th 06 12:59 PM
Republicans Rule Mark Misc 5 May 28th 04 12:56 PM
Does Religion Rule ? G=EMC^2 Glazier Misc 2 March 4th 04 11:34 AM


All times are GMT +1. The time now is 05:18 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright ©2004-2020 SpaceBanter.com.
The comments are property of their posters.