How about a "Double-Barrel" Ares I?

I've been following that there have been concerns whether it would be
powerful enough to put an Orion into orbit, leading to the development
of the 5-seg SRB, and then that might not be enough either.

So, why not "double-barrel" a pair of 4-segs mounted side by side, with
either the rest of the stack mounted asymmetrically on top of one SRB or
symmetrically with an inverse Y-shaped connection?

(Rubbish ASCII art follows)

| |
A A
H H
H H
# A /-\
H-H or H-H
H-H H-H
H-H H-H
H-H H-H
^ ^ ^ ^

Silly idea?

Matt

On Sun, 29 Jul 2007 20:03:23 GMT, in a place far, far away,
Cruithne3753 made the
phosphor on my monitor glow in such a way as to indicate that:

I've been following that there have been concerns whether it would be
powerful enough to put an Orion into orbit, leading to the development
of the 5-seg SRB, and then that might not be enough either.

So, why not "double-barrel" a pair of 4-segs mounted side by side, with
either the rest of the stack mounted asymmetrically on top of one SRB or
symmetrically with an inverse Y-shaped connection?

No longer "simple," which was supposed to be one of its virtues.
Plus, it would cost considerably more per flight, and introduce a new
failure mode of potentially asymmetric thrust.

Cruithne3753 wrote in
. uk:

So, why not "double-barrel" a pair of 4-segs mounted side by side, with
either the rest of the stack mounted asymmetrically on top of one SRB or
symmetrically with an inverse Y-shaped connection?

Two problems:

Excessive thrust with excessive acceleration. This is about
6 million lbs/thrust on a vehicle that weighs a fraction of
Shuttle.

Takes a simple concept and makes it unnecessarily complex.
The assymetric configuration has been suggested on other
launchers so it might be workable but still comes back to
the first issue.

Perhaps a 'super-sized' Ariane V configuration with three-
segment SRBs to reduce thrust? This still suffers from
problem the second. I'd rather go with a down-sized Ares V
and just not deal with big, skinny long solid/liquid stacks.

The Stick is an awkward concept that just doesn't look
'right', especially when one tries to fix its shortcomings.
The logic that retaining uninterrupted use of Shuttle
SRBs is going to save money seems questionable.



--Damon

On Sun, 29 Jul 2007 15:19:35 -0500, in a place far, far away, Damon
Hill made the phosphor on my monitor glow
in such a way as to indicate that:

Cruithne3753 wrote in
.uk:

So, why not "double-barrel" a pair of 4-segs mounted side by side, with
either the rest of the stack mounted asymmetrically on top of one SRB or
symmetrically with an inverse Y-shaped connection?

Two problems:

Excessive thrust with excessive acceleration. This is about
6 million lbs/thrust on a vehicle that weighs a fraction of
Shuttle.

That could be fixed with a suitably large upper stage. But then, it
would have too much payload, which means that we'd have to (horrors!)
mix crew and cargo, and *everyone* knows that's unsafe...

Rand Simberg wrote:

That could be fixed with a suitably large upper stage. But then, it
would have too much payload, which means that we'd have to (horrors!)
mix crew and cargo, and *everyone* knows that's unsafe...

Yep... silly.

At least my idea didn't have excessive amounts of capitalization in the
text. :-)

"Rand Simberg" wrote in message
...
On Sun, 29 Jul 2007 20:03:23 GMT, in a place far, far away,
Cruithne3753 made the
phosphor on my monitor glow in such a way as to indicate that:

I've been following that there have been concerns whether it would be
powerful enough to put an Orion into orbit, leading to the development
of the 5-seg SRB, and then that might not be enough either.

So, why not "double-barrel" a pair of 4-segs mounted side by side, with
either the rest of the stack mounted asymmetrically on top of one SRB or
symmetrically with an inverse Y-shaped connection?

No longer "simple," which was supposed to be one of its virtues.

Yes, but I think we passed "simple" a few revisions ago.


Plus, it would cost considerably more per flight, and introduce a new
failure mode of potentially asymmetric thrust.


You know, toss a tank for liquid fuel between them, an off-center orbital
unit, put a capsule on top and who knows, you may be on to something ;-)




--
Greg Moore
SQL Server DBA Consulting Remote and Onsite available!
Email: sql (at) greenms.com http://www.greenms.com/sqlserver.html

Rand Simberg wrote:

On Sun, 29 Jul 2007 20:03:23 GMT, in a place far, far away,
Cruithne3753 made the
phosphor on my monitor glow in such a way as to indicate that:



I've been following that there have been concerns whether it would be
powerful enough to put an Orion into orbit, leading to the development
of the 5-seg SRB, and then that might not be enough either.

So, why not "double-barrel" a pair of 4-segs mounted side by side, with
either the rest of the stack mounted asymmetrically on top of one SRB or
symmetrically with an inverse Y-shaped connection?



No longer "simple," which was supposed to be one of its virtues.
Plus, it would cost considerably more per flight, and introduce a new
failure mode of potentially asymmetric thrust.



That's not really an issue. Look at the Shuttle... the SRBs are much
further apart, and thus thrust imbalance would be far more noticable...
and yet it hasn't really been an issue. Put the two motors right next to
each other, and the problem becomes much simpler to deal with.


--
-------
The fact that I have no remedy for all the sorrows of the world is no reason for my accepting yours. It simply supports the strong probability that yours is a fake. - H.L. Mencken

On Sun, 29 Jul 2007 21:39:09 GMT, in a place far, far away, Scott
Lowther made the phosphor on my
monitor glow in such a way as to indicate that:

So, why not "double-barrel" a pair of 4-segs mounted side by side, with
either the rest of the stack mounted asymmetrically on top of one SRB or
symmetrically with an inverse Y-shaped connection?



No longer "simple," which was supposed to be one of its virtues.
Plus, it would cost considerably more per flight, and introduce a new
failure mode of potentially asymmetric thrust.



That's not really an issue. Look at the Shuttle... the SRBs are much
further apart, and thus thrust imbalance would be far more noticable...
and yet it hasn't really been an issue.

Until one lights, and the other doesn't...

Sorry, Scott, but I'm just parroting the justification for The
Shaft...errrrr...Stick.

On Jul 29, 5:22 pm, (Rand Simberg)
wrote:

Until one [SRB] lights, and the other doesn't...

I know this has been talked about over the years, but please remind
me:

What are the statistics for any biggish solid rocket failing to light
when it was supposed to? I well appreciate that solids have their
failure modes from seeing impressive pictures of the consequences. But
has Failure To Ignite really been a problem?

On Sun, 29 Jul 2007 15:29:53 -0700, in a place far, far away, Allen
Thomson made the phosphor on my monitor glow in
such a way as to indicate that:

On Jul 29, 5:22 pm, (Rand Simberg)
wrote:

Until one [SRB] lights, and the other doesn't...

I know this has been talked about over the years, but please remind
me:

What are the statistics for any biggish solid rocket failing to light
when it was supposed to? I well appreciate that solids have their
failure modes from seeing impressive pictures of the consequences. But
has Failure To Ignite really been a problem?

It's happened on smaller solids (e.g., Deltas).

But statistically, it probably isn't a problem, given how seldom NASA
launches its own launch vehicles at all.

Costs, on the other hand...

In any event, again, I'm simply parroting the arguments in favor of
The Shaft^H^H^H^H^HStick.