2005-07-12 06:27:45 UTC
big fan of the SRB solution, as you'll see.
Replacement Saturn-IB: Two Atlas-V cores (roughly 2Mlbf total) strapped
on to a new core with a single SSME upper stage - it's overpowered for
this application (it needs to be around 300Klbf I'm guessing), but
there's nothing else in that class besides J-2S and why bother bringing
that old fart back when they could just use a throttled-back SSME, with
higher performance and a current production line (and commonality with
the HLLV below)? The core is based on Delta 4, although heavily
modified to use a SSME and mate with Atlas V's.
Replacement Saturn-V: Six uprated Atlas-V cores -- RD-170's or dual RD-
180's (12Mlbf thrust total) attached to a new core (air-started?) with
three SSME's (1.5Mlbf total) and the third stage using one SSME (again
the question, make it restartable for TLI or just bring back the J-2S?
I say improve the SSME). Personally I don't understand WHY they're so
intent on using the Shuttle tank??? By the time they're done modifying
it, it'll be a completely new tank anyway might as well make it 10
meters diameter like the old S-II stage and use a nice big 10 meter
After CEV development is completed, bring back something like the RS-84
as a domestic replacement for the RD-180 for the Atlas V. Make it a
2Mlbf high-pressure hydrocarbon engine, and throttle it down for the base
Atlas V. Bring out a SSME Block III, with lower chamber pressure,
higher area ratio (now assuming air-start), and reduced cost (due to
lower pressures and simplified design). And, if some day EELV produces
something like a RL-60, it could potentially be used in place of the
single SSME on the replacement S-IVB stage... though I'm a little
skeptical of how many would be required.
Build two new pads or refurbish LC39 and make them state-of-the-art.
Both launch vehicles will use the same pads, with identical crew towers
(same height for accessing the CEV). They actually did this later on
with the Saturn-IB for the Skylab missions - put it on top of a "milk
stool" (girder taking up the extra height) and launched them from LC39
just like the Saturn-V. They found they could save a lot of money and
decommission the old Saturn-IB pads completely by using the "milk stool"
trick - they never needed them in the first place if they'd just used
So, we'll leverage both EELV (thus driving down their launch costs and
making the military happy) and Shuttle-derived hardware (where it fits
well), and build a pair of man-rated pads so our operations don't
interfere with their commercial operations and also because there will be
significant differences between VSE vehicles and EELV -- not the least of
which is the crew-access tower.
I would have like to have found a use for RS-68 and more for Delta 4 to
do, but frankly, the RS-68 is a dog and I doubt the cost savings of the
engine are a good trade-off on the 2nd stage of a moon-mission HLLV, and
it's too big to replace the J-2S... so there's no chair for it at the
table I'm afraid.