Why only two SRB's for Inline?

I was thinking, if NASA does go with the Inline SDLV, why only limit
themselves to 2 SRB's? Since the ET and LC-39 is going to require a
significant redesign anyway to support the new launcher, why not add
additional flexibility by allowing 2 or 4 SRB's to be used depending
on payload requirements. Similar to General Dynamics GD-E Nova
proposal.

Kelly McDonald

Kelly McDonald wrote:
I was thinking, if NASA does go with the Inline SDLV, why only limit
themselves to 2 SRB's? Since the ET and LC-39 is going to require a
significant redesign anyway to support the new launcher, why not add
additional flexibility by allowing 2 or 4 SRB's to be used depending
on payload requirements. Similar to General Dynamics GD-E Nova
proposal.

Kelly McDonald

apparently that's what Mike Griffen already has planned, or at least
has considered as an alternative:

http://fti.neep.wisc.edu/neep533/FALL2001/lecture29.pdf

Got this from Rand's site via Sam Dinkin, ("Griffen")

http://www.transterrestrial.com/arch...52.html#005452

Tom Cuddihy

Tom Cuddihy wrote:
Kelly McDonald wrote:
I was thinking, if NASA does go with the Inline SDLV, why only limit
themselves to 2 SRB's? Since the ET and LC-39 is going to require a
significant redesign anyway to support the new launcher, why not add
additional flexibility by allowing 2 or 4 SRB's to be used depending
on payload requirements. Similar to General Dynamics GD-E Nova
proposal.

Kelly McDonald

apparently that's what Mike Griffen already has planned, or at least
has considered as an alternative:

http://fti.neep.wisc.edu/neep533/FALL2001/lecture29.pdf

Got this from Rand's site via Sam Dinkin, ("Griffen")

http://www.transterrestrial.com/arch...52.html#005452

Tom Cuddihy


BTW, the different SDV concepts are on page 14 of the pdf, under 1a and
1b.
1a is the familiar looking 2 SSME ET based SDV with a preliminary
estimated performance of about 120 mtertic tons.
1b is the 4 SRSM model--interestingly, it baselines an airstart of the
SSME-ET core(3 SSMEs), at about 100s, with estimated performance of 207
metric tons-- LEO.

Personally, I wonder what kind of modifications 12 million lbf of
thrust at liftoff requires being made to the launch facilities.

cuddihy