Re: Griffin Wants Inline SDLV and 5 Segment SRB/CEV


"Rand Simberg" <simberg.interglobal@xxxxxxxxx> wrote in message
news:42eb8043.206610129@xxxxxxxxxxxxxxxxxxxxxxxxxxx
> On Sun, 10 Jul 2005 22:17:45 -0400, in a place far, far away, "Murray
> Anderson" <murraya@xxxxxxxxxxxx> made the phosphor on my monitor glow
> in such a way as to indicate that:
>
> >> >> >They didn't know how refurbishable the solid would be either.
> >> >>
> >> >> They did, since they don't refurbish it--they rebuild it from the
> >> >> recovered segments, with new grain.
> >> >>
> >> >It's the same with a liquid booster, except for the engine assembly -
you
> >> >just refill the tanks.
> >>
> >> No, it's not that simple. The solids consist of segments, which can
> >> be broken down and rebuilt. A liquid would have huge tanks that would
> >> have to be inspected.
> >>
> >
> >That doesn't establish an advantage for the solids. You could just as
well
> >say the liquids have tanks that only have to be inspected whereas the
solids
> >have to be rebuilt.
>
> It's easy to inspect a "tank" that's a segment. It's much harder to
> do so with a complete tank (one that would also be much lighter
> weight, and thus more suspect, and subject to more damage upon hitting
> the water).
>

The difference in weight would be about a factor of 2 (7% versus 14%), and
the liquid tanks could be made somewhat heavier if necessary.
If you take a solid rocket booster apart you have to put it back together
with the attendant risk of damage, since the segments tend not to be
perfectly circular when you put them back together.

> >> >The engine nozzle and gimballing system of the solid are supposedly
> >> >recovered and reused, which would be like the engine assembly on the
> >> >liquid - except for the turbopump system.
> >> >There would be a difference if the turbopump system were harder to
> >protect
> >> >from seawater than the gimballing system on the solid.
> >>
> >> As indeed it would.
> >
> >You have a source for this?
>
> Just common sense, and it was the judgement at the time. I really
> don't understand why you're second guessing all of this.
>

The gimballing system requires a power source, which is provided by a
turbine driven by the decomposition of hydrazine. This drives the hydraulic
pumps - so you have the same sort of system to protect from sea water as
with a liquid rocket engine turbopump system.
It's not just common sense.

> >> >> >That's a restatement of the problem in other words, together with a
> >> >> >rationalization. What was it they wanted to do and didn't have the
> >money
> >> >> >for? A better thermal protection system would help, but that wasn't
on
> >> >> >offer, was it?
> >> >>
> >> >> With more money, yes. They could have, for example, used a titanium
> >> >> structure underneath, instead of aluminum.
> >> >>
> >> >But the problem is the susceptibility to debris damage, not the
> >insulating
> >> >qualities of the tiles.
> >>
> >> That's only part of the problem.
> >>
> >
> >And what is the other part of the problem?
>
> The maintainability of the main engines, the toxicity of the OMS and
> RCS, and APU propellants, the fragility of the TPS, the complexity of
> payload integration, etc.

Murray Anderson


.

Relevant Pages

  • Re: Griffin Wants Inline SDLV and 5 Segment SRB/CEV
    ... The solids consist of segments, ... A liquid would have huge tanks that would ... >That doesn't establish an advantage for the solids. ... >>>from seawater than the gimballing system on the solid. ...
    (sci.space.policy)
  • Re: Griffin Wants Inline SDLV and 5 Segment SRB/CEV
    ... >>> That would still have cost more than they had budget for (solids are ... >>> how refurbishable a liquid in that class would be after being dropped ... >>> probably will cost more than the development of the ... >>The record is good for solids, and is consistent with the view reported ...
    (sci.space.policy)
  • Re: A very basic question...
    ... A lot of chemistry necessary for life requires liquid solvents. ... Lots of different scientists from lots of different countries stand behind the same claim. ... Most solids are denser than their liquid phase, sink to the bottom and stay there allowing the entire bulk the solidify. ...
    (uk.sci.astronomy)
  • Re: Griffin Wants Inline SDLV and 5 Segment SRB/CEV
    ... >>> recovered segments, with new grain. ... A liquid would have huge tanks that would ... That doesn't establish an advantage for the solids. ... >>from seawater than the gimballing system on the solid. ...
    (sci.space.policy)
  • Re: Does NASA save money reusing SRBs?
    ... yet nobody else reuses their solids. ... If nobody has done something, it's wrong to say we know ... Personally I think there's more potential for reusing strap-ons than any ... > Same goes with liquid. ...
    (sci.space.policy)