Re: SRB-Based EELV Launcher Article

From: ed kyle (edkyle99_at_hotmail.com)
Date: 09/20/04 

Date: 20 Sep 2004 07:56:31 -0700

gigantin@shore.net (Josh Gigantino) wrote in message news:<d5952843.0409161442.370cdc6b@posting.google.com>...
> edkyle99@hotmail.com (ed kyle) wrote in message news:<88d21cfd.0409130456.4a287e58@posting.google.com>...
> > We first discussed this in Feb 2004. It is an idea with
> > some merit, I think, that just refuses to go away.
> >
> > "http://www.thespacereview.com/article/226/1"
>
> Has anyone figured out if this SRB-proposal would really be pulling
> 20Gs at burnout? Nozzles could be redesigned along with the rest of
> the vehicle, adding thrust-termination, diagnostics etc. Is the SRB a
> square peg for an SS1-shaped hole?
>
If the upper stage and payload together have enough mass,
the vehicle would only see 3.5-5.5 Gs at first stage (SRB)
burnout. If, for example, SRB lifted a 120 metric ton
(gross) S-IVB class stage (a bit more than 1/2 the mass
of a Delta IV first stage!) with an 18 metric ton payload,
the SRB burnout mass would be about 226 metric tons and
the acceleration would be about 5.2 Gs. Or, heck, put a
Delta IV first stage on top of an SRB. Then the burnout
mass would be about 332 metric tons for a 3.5 G
pre-staging acceleration. Mind you, I'm not saying that
such a design is physically possible.

IMO, the kicker here is the need to develop an all-new
big upper stage - the bigness of which would require a
new (or retro-revised) upper stage engine. That's big
bucks. SRB-based vehicles only make sense to me if a new
upper stage were also needed for the EELV-based vehicles
(which may be the case).

 - Ed Kyle

Relevant Pages

  • Re: CEV cost SKYROCKETING!
    ... SRB for CaLV. ... Keep in mind that this extra cost is a small percentage ... This might cost even more because a new upper stage, ... The Delta IV upper stage has an initial thrust to weight ...
    (sci.space.shuttle)
  • Re: NASAs Ares I - The Stick is not big enough
    ... upper stage diameter = flies stable only backwards) wobbling long thin ... pointing the thrust vector through the center of gravity be such means ... SRB thrust vectoring on the STS-stack has to to? ... but launching delicate and really lightweight ...
    (sci.space.policy)
  • Re: NASAs Ares I - The Stick is not big enough
    ... upper stage diameter = flies stable only backwards) wobbling long thin ... pointing the thrust vector through the center of gravity be such means ... SRB thrust vectoring on the STS-stack has to to? ... but launching delicate and really lightweight ...
    (sci.space.policy)
  • Re: NASAs Ares I - The Stick is not big enough
    ... Rand Simberg wrote: ... upper stage diameter = flies stable only backwards) wobbling long thin ... pointing the thrust vector through the center of gravity be such means ... SRB thrust vectoring on the STS-stack has to to? ...
    (sci.space.policy)
  • Re: NASAs Ares I - The Stick is not big enough
    ... upper stage diameter = flies stable only backwards) wobbling long thin ... pointing the thrust vector through the center of gravity be such means ... SRB thrust vectoring on the STS-stack has to to? ...
    (sci.space.policy)