Re: GRIFFIN'S DRIVE FOR SHUTTLE-DERIVED

Damon Hill wrote:
> "Ed Kyle" <edkyle99@xxxxxxxxxxx> wrote in news:1117916500.022455.222330
> @o13g2000cwo.googlegroups.com:
>
> >
> > But Boeing is selling Rocketdyne to Pratt, so it
> > seems unlikely now that we'll see any RS-68 upgrades.
> > Pratt is already preparing to co-produce RD-180,
> > which is a better high-thrust booster engine than
> > RS-68. Pratt/Rocketdyne already have SSME, which is
> > a better high-performance cryo engine than RS-68.
> > NASA has recently spent tons of money on SSME for
> > turbopump upgrades, etc., so NASA isn't going to
> > abandon SSME easily. RS-68, on the other hand, has
> > been effectively abandoned by Boeing and so seems to
> > be an orphan with an uncertain future.
>
> Huh? Where is this written? I don't follow this
> logic at all.

I suppose I wrote it! Here is my logic.

After having lost billions, Boeing is backing away
from the volatile space launch business. It is
selling Rocketdyne, giving up control of RS-68 and
SSME in the process. It is dumping Delta IV onto a new
joint operation with Lockheed called Space Launch
Alliance (SLA) that will also encompass Atlas V. SLA
promises to continue side-by-side production of both
EELVs, but who really believes that? Everyone knows that
there isn't enough business for both rockets. Everyone
knows that costs have to be slashed. Total EELV program
costs have *doubled* - this for a program that promised
to *cut* launch costs. Congress is not happy about this.
One of these EELVs is going to fall by the wayside
eventually. Maybe not right away, but eventually, in
a few more years at the most.

Which EELV will survive? My guess is that the one that
has both the highest core lifting capacity and the lowest
costs stands a pretty good chance. That would be Atlas V.

Without Delta IV, RS-68 has no home unless NASA uses it.
And the early indications are that NASA wants to use SSME,
not RS-68.

RS-68 is a compromise engine, a fussy high-performance
technology (cryo LH2) mis-used in a high-thrust application
that does not take full advantage of the high-energy
possibilites of the fuel. Because it is "low-cost", it is
both heavy and relatively "low performance". A hydrocarbon
engine could provide similar high-thrust performance for
less cost, the RD-180 being evidence.

RS-68 could be sold to NASA if the salesmanship were good
enough. But who at Pratt will want to sell the thing
now that the company also has control of both the higher
performance (and higher budget) SSME AND the lower budget,
but still higher thrust RD-180?

- Ed Kyle

.

Relevant Pages

  • Re: SSME vs. J2 / RS-68
    ... at EELV's and EELV derived vehicles rather than insisting on this "shuttle ... NASA Eyes Alternative to Shuttle Main Engine for Heavylift ... J-2S for the stick's upper stage, in place of an air started SSME. ... and performance merits of the SSME and RS-68. ...
    (sci.space.history)
  • SSME vs. J2 / RS-68
    ... NASA Eyes Alternative to Shuttle Main Engine for Heavylift ... NASA is considering dropping the Space Shuttle Main Engine (SSME) from ... and performance merits of the SSME and RS-68. ...
    (sci.space.history)
  • Re: NASA Eyes Alternative to Shuttle Main Engine for Heavylift
    ... Maybe common sense is not totally dead at NASA. ... That NASA is doing trade studies on SSME versus RS-68 ... This suggests that a RS-68 design is a lot cheaper ...
    (sci.space.policy)
  • Re: GRIFFINS DRIVE FOR SHUTTLE-DERIVED
    ... > seems unlikely now that we'll see any RS-68 upgrades. ... Pratt/Rocketdyne already have SSME, which is ... > turbopump upgrades, etc., so NASA isn't going to ...
    (sci.space.policy)
  • Re: GRIFFINS DRIVE FOR SHUTTLE-DERIVED
    ... > But RS-68 would then have to be reengineered at ... Putting a bigger ablative nozzle on does not need reengineering at ... > costs presumable doubled along with the program. ... but this would also be true for SSME. ...
    (sci.space.policy)