Shuttle Derived Launchers - Safe, Simple, Soon

"Murray Anderson" wrote in message
...

"Ed Kyle" wrote in message
oups.com...
There is one shuttle-derived concept floating around
that is claimed to be able to put 850 Klbs into low
earth orbit or 340 Klbs on a translunar trajectory.
It is an ET core (LOX/RP) with six RD-180s, boosted
by six RSRMs, topped by an ET-based LOX/LH2 second
stage powered by three SSMEs. It looks like a
Delta 2, except 450 feet tall with a 28 foot diameter
core! The thing would weigh 14.4 million pounds at
liftoff and would create 21 million pounds of liftoff
thrust. Its name is MAX (Mars Express).

That's an implausible figure for payload, since it's about 6% of the
takeoff
weight. The Atlas III was rated at about 4.7%, and it wasn't burdened with
the low performance SRBs. I'd say about 600 000 lbs max to LEO (just over
4%) and 240 000 translunar.

Why is that implausible when you consider the ISP of the RD-180's and the
ISP of the SSME's (you could even extend the SSME nozzles for a bit more
vacuum ISP).

In other words, a BOTE calculation based on % payload mass likely isn't
detailed enough.

Jeff
--
Remove icky phrase from email address to get a valid address.

Phil Bagust wrote:

At what point do we just say 'enough'? If this thing ever got built, and
heaven forbid fell back onto the pad, the resulting explosion would make
the N1 debacle look like a firecracker.


I'd still like to see one of these blow up on the pad:
http://www.astronautix.com/lvs/ur900.htm

Pat

"Jeff Findley" wrote in message
...

"Murray Anderson" wrote in message
...

"Ed Kyle" wrote in message
oups.com...
There is one shuttle-derived concept floating around
that is claimed to be able to put 850 Klbs into low
earth orbit or 340 Klbs on a translunar trajectory.
It is an ET core (LOX/RP) with six RD-180s, boosted
by six RSRMs, topped by an ET-based LOX/LH2 second
stage powered by three SSMEs. It looks like a
Delta 2, except 450 feet tall with a 28 foot diameter
core! The thing would weigh 14.4 million pounds at
liftoff and would create 21 million pounds of liftoff
thrust. Its name is MAX (Mars Express).

That's an implausible figure for payload, since it's about 6% of the
takeoff
weight. The Atlas III was rated at about 4.7%, and it wasn't burdened
with
the low performance SRBs. I'd say about 600 000 lbs max to LEO (just
over
4%) and 240 000 translunar.

Why is that implausible when you consider the ISP of the RD-180's and the
ISP of the SSME's (you could even extend the SSME nozzles for a bit more
vacuum ISP).

In other words, a BOTE calculation based on % payload mass likely isn't
detailed enough.

Jeff
--
Remove icky phrase from email address to get a valid address.



The proposed Atlas V upgrade to a larger Centaur gives 26.6 tons payload to
a 100 nm orbit. The liftoff weight would be about 600 tons, including 225
tons solids, 305 tons core stage, and 65 tons upper stage plus payload.
That's about 4.5% and includes more RD-180 in relation to solids than the
proposed configuration. See the Atlas mission planner guide, section 8, page
9.
Maybe 4% is a little low - but 6% is unreasonable.

Murray Anderson

Griffin wrote a text just a few years ago suggesting using shuttle
derived hardware for the moon-mars goal. I think I remember seeing the
article in an IAAA journal.

Gene

"Jeff Findley" wrote in message
...
Sounds like this would be a 2X size space shuttle. Exactly how would this
be better than the current shuttle?

You could blow up twice as much stuff.