Would it make any difference if you didn't care if they returned to the
launch site vs. just being retrievable? Like say a TAL flight? Benefits,
drawbacks?

A better approach might be to return to the launch site by having the first
stage launch essentially straight up. Sure, the second stage takes a bit of
a performance hit since the first stage didn't give it any additional
horizontal velocity (compared to an "optimal" two stage launch vehicle),

Jeff Findley wrote:
A better approach might be to return to the launch site by having the
first
stage launch essentially straight up. Sure, the second stage takes a bit
of
a performance hit since the first stage didn't give it any additional
horizontal velocity (compared to an "optimal" two stage launch vehicle),

I would suspect "a bit of a hit" would be a fairly major understatement.

Since orbit is all about horizontal speed, I suspect that it would be a
major hit. A lot of fuel would be expanded to raise the stack without
giving it any horizontal speed. Once the LFBBs are expanded, the stack
would have 0 horizontal speed and would then need to use its second
stage to do 100% of the acceleration needed to reach orbital speed.

The only advantage is that the second stage would start off at a higher
altitude with less drag from atmosphere.

Possibly, but I'd think that a TAL flight would be awfully far downrange for
a typical first stage recovery operation. The trouble with this approach is
you need several first stage recovery sites if you're going to launch to
different inclinations. This starts to drive up fixed costs if every
recovery site needs special equipment to handle the landing of the first
stage.

A better approach might be to return to the launch site by having the first
stage launch essentially straight up.

Also, how likely was it that the copy of Bill Gerstenmaier that jogged
past me on the beach a couple miles south of the port wearing an STS-1
t-shirt was the original?

A better approach might be to return to the launch site by having the first
stage launch essentially straight up. Sure, the second stage takes a bit of
a performance hit since the first stage didn't give it any additional
horizontal velocity (compared to an "optimal" two stage launch vehicle), but
so what? If it makes recovery of the first stage a lot easier, it might be
well worth the trouble for the second stage. A bonus for the first stage
launching straight up is that this approach works well for varying
inclinations since the first stage always comes down at the launch site.

I saw this post today, at 2:38 pm CDT 3/12. Bill Gerstenmeier walked past
my console in the MER at JSC this morning about 9 am. Hence the
likelihood, while not zero, is fairly small.

On or about Wed, 12 Mar 2008 16:13:53 -0400, Jeff Findley
jeff.findley@ugs.nojunk.com> made the sensational claim that:
Possibly, but I'd think that a TAL flight would be awfully far downrange
for
a typical first stage recovery operation. The trouble with this approach
is
you need several first stage recovery sites if you're going to launch to
different inclinations. This starts to drive up fixed costs if every
recovery site needs special equipment to handle the landing of the first
stage.

This argument isn't very convincing given we don't have much of a problem
with
finding shuttle abort sites, but then I suppose you could say we don't use
them
every launch.

I guess I'm just fixated on the "flyback" aspect, and wonder if you
couldn't
gain some things by not insisting on returning to the launch site, since I
imagine that places some restrictions on size and speed.

On Wed, 12 Mar 2008 16:13:53 -0400, "Jeff Findley"
jeff.findley@ugs.nojunk.com> wrote:


A better approach might be to return to the launch site by having the
first
stage launch essentially straight up.

Launch failure and range safety destruct results in debris falling all
over the launch site, and possibly onto populated areas. The higher
the detonation, the bigger the fallout zone, even Orlando and Dizzy
World might be rained on if the wind is right. Not good.

Who said anything about launching from KSC? I'd rather new systems launch
from places more like Edwards AFB, where such failures are (or historically
were) accepted as standard operating procedure when testing high performance
experimental aircraft.

Launch failure and range safety destruct results in debris falling all
over the launch site,

Who said anything about launching from KSC? I'd rather new systems launch
from places more like Edwards AFB,

So... to save a little money, you want to uproot the entire U.S.
launch infrastructure and rebuild it 3,000 mile away?

Who said anything about launching from KSC? I'd rather new systems launch
from places more like Edwards AFB, where such failures are (or historically
were) accepted as standard operating procedure when testing high performance
experimental aircraft.

It's a hell of a lot easier to land such a vehicle on a huge, dry lakebed
than to try to land it on a relatively small concrete runway or landing pad
surrounded by swampland.