Re: GRIFFIN'S DRIVE FOR SHUTTLE-DERIVED

Pat Flannery wrote:
>
> SRBs can be fired in a horizontal position- can they be assembled in
> that position also? If that's the case, then the could be assembled -
> CEV and all - horizontally; then taken to the pad and erected prior to
> launch, much as is done with a Proton rocket:
> http://www.harcourtschool.com/activity/space_station/images/delay2.jpg
> http://www.spacetoday.org/images/Rockets/Russia/Proton300thLaunchRolloutILS.jpg
>

We discussed this yesterday somewhere in this
thread. It turns out that the main problem
would be the shear mass of an SRB. One SRB
weighs something like 590 metric tons, much
more than the 88 ton MX missile or the 35 ton
Minuteman (or the 70-ish ton empty Proton).

The heaviest rocket I can think of that was
ever transported horizontally and then erected
at the pad was Energia/Buran, which weighed
about 300 tons empty - more than the big N-1
rocket which was similarly transported using
the same massive "Grasshopper" transporter/
erector.

Individual SRB segments are transported
horizontally on railcars and are rotated to
vertical in the VAB, so there is nothing that
prevents big solid motor segments from being
horizontal. One of the reasons that the SRB
is segmented is that the VAB bridge crane has
a max loading of "only" 250 tons.

Monstrous floating cranes have lifted heavier
objects. One of the biggest floating cranes
lifted an 800 ton bridge into place in the UK,
for example. If an SRB could be adequately
supported by a "Grasshopper-Times-Two" class
erector (which itself would have to be the size
and mass of a high-rise building), and if this
massive erector could be made to move (a problem
that would provide another big engineering project
all by itself), and if a massive enough lifting
system could be provided to erect such a beast
(I suppose it would work like a drawbridge),
it might then be possible to do horizontal SRB
integration.

- Ed Kyle

.

Relevant Pages

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