"Damon Hill" wrote in message
32...
"Dholmes" wrote in
:



Where would reusable liquid boosters come from?

The Russians are/were working on just such a design for future
use with the Angara, the replacement launch vehicle family for Proton
and Soyuz. Uses a single-chamber variant of the RD-180 engine.

I checked and Boeing is working on a reusable Kerosene rocket for NASA.


Any sort of boosters with more thrust, even solids, would be a big
boost to Delta.

That's called Delta IV Heavy, using three CBCs fired in parallel.
But I was thinking of the CBC as a serious second stage, with
a couple of kerosene/LOX boosters or Titan IV-class solids. Modify
the RS-68 for altitude operation with an enlarged expansion nozzle;
a SSME with higher Isp could work here too but its expensive to
throw away.

The solids on Delta are very underpowered. The ones on Atlas have over twice
as much fuel.
Delta 2 uses up to 9 I can see no reason Delta 4 could not as well.
A pair of reusable solids about half the size of the shuttles for both Atlas
and Delta could prove interesting.
The question is would it be cheaper.
Delta's main engine makes a killer second stage for a very large rocket.
Another option would be to use slightly shortened Deltas, 3 at launch and
one as a second stage. but kerosene do seem to work best as a booster stage.

A second stage with nore thrust would help for LEO as well.

The MB-60 or RL60 with up to 65,000 lbs/thrust are in development
to replace the current 22,000 lbs/thrust RL10; this should be
the first major upgrade to Delta IV. This will help with gravity
losses while avoiding having to use two or more RL-10s and would
make possible an enlarged upper stage, if needed.

True, I was really hoping for someting a little bigger but it should be a
big help to LEO.
Beyond GTO it and a RL-10 combined could prove really powerfull.

This still wouldn't be Saturn V class, but would be reasonably
off-the-shelf.

5 RD-170s as a first stage.
3 RS-68s as a second stage.
1 RS-68 as a third stage.
Sounds close to me.


Massively clustered Delta IV CBDs with propellant cross-feed
would be technically possible, and get into heavy-lift range with
a relatively affordable mass-produced modular design.

--Damon