SRB-Based EELV Launcher Article

Rand Simberg wrote:
(ed kyle) glowed:
We first discussed this in Feb 2004. It is an idea with
some merit, I think, that just refuses to go away.

"http://www.thespacereview.com/article/226/1"

My comments:
http://www.transterrestrial.com/arch...72.html#004272

My initial thought, reading the SRB based booster article:

"Why are we still talking about 20 ton payloads for
8 seat capsules?"

Now that Wings are mostly off the table, the ongoing
quest for larger, more expensive booster options has
gone from indiscreet to appalling. To fly 8 people to
the space station, you don't need a $100 million 20 ton
to SSO launcher, you can do it just fine on a much
smaller EELV, or a pair of Falcon-V boosters.


-george william herbert

George William Herbert wrote: My initial thought, reading the SRB based
booster article:

"Why are we still talking about 20 ton payloads for
8 seat capsules?"

Now that Wings are mostly off the table, the ongoing
quest for larger, more expensive booster options has
gone from indiscreet to appalling. To fly 8 people to
the space station, you don't need a $100 million 20 ton
to SSO launcher, you can do it just fine on a much
smaller EELV, or a pair of Falcon-V boosters.

Quite. Even 10 tonnes buys a whole lot of hardware for
a sizeable crew, especially with modern technologies and
a decent sized capsule diameter. 20 tonnes is basically
a Shuttle-killer, with all the room and functions of
the Shuttle after you shave off the insane bulk of the
cargo bay, SSMEs, wings, and their consequent friends in
support structures. 20 tonnes buys you, really, a
space station. The Salyut's up through 6 all weighed
under 20 tonnes.

"Christopher M. Jones" wrote:

20 tonnes buys you, really, a
space station.

Good. The purpose of this capsule launcher isn't to throw people at the
space station, but at the moon. Rather a lot more hardware required for
that.

Save the people-station-lobbers for Spaceship 3 and the like.

On Tue, 14 Sep 2004 03:14:31 GMT, in a place far, far away, "Greg D.
Moore \(Strider\)" made the phosphor
on my monitor glow in such a way as to indicate that:

In the event of a problem, the capsule fires its abort motors, gets
clear
and the SRB shreds its skin.

Only if the problem is known in time.

Same issue with any launcher.

Not with human-rated ones, by definition.

Which don't exist. Turning an SRB into one isn't necessarily any harder
than turning an existing EELV into one.

It is for the Delta, which can be shut down. In addition, there is
much more existing infrastructure for FOSD on the EELVs, since they're
already launch systems (as opposed to the SRB, which is simply a
strap-on booster with little in the way of sensors, since there no
ability to use diagnostic information from it).

I'm not defending EELV, though--I think the entire CEV concept
(putting up a capsule on an expendable) is dumb.

On Tue, 14 Sep 2004 03:21:30 GMT, in a place far, far away, Scott
Lowther made the phosphor on my
monitor glow in such a way as to indicate that:

If you're going to count this problem against the SRB, you have to be fair
and count it against any launcher being considered for CEV.

I suspect what Rand will *eventually* get around to is dropping vague hints
that what he's *really* after is some privately developed fully reusable
craft, and anything else is a horrendous waste of time and money.

Why hint? I said it quite clearly and explicitly in my essay in The
New Atlantis.

He's wrong, of course, but such optimism and naivite is to be expected in the
very young.

I wish I were very young.

On 13 Sep 2004 21:02:20 -0700, in a place far, far away,
made the phosphor on my monitor glow in such a
way as to indicate that:

An equaly serious objection: the US launcher market can barely
support two
launchers in that payload range. Three woud be even tougher
economics.


The economics are already tough. Both EELVs are already
government supported, having failed to be commercially
competitive with Proton, Zenit, or Ariane. If NASA can
do it cheaper with its own design, shouldn't it?

Perhaps, but there's no reason to think it can. The article didn't
have enough cost data to indicate that. I'll bet the cost they quoted
was marginal, and didn't include amortization of either development
costs or fixed annual costs.

"Scott Lowther" wrote in message
...


"Christopher M. Jones" wrote:
20 tonnes buys you, really, a
space station.

Good. The purpose of this capsule launcher isn't to throw people at the
space station, but at the moon. Rather a lot more hardware required for
that.

Save the people-station-lobbers for Spaceship 3 and the like.

Actually, you only have to get the people to LEO. After that, you dock with
another module (sent up on another booster) that provides living space and
life support for the duration of the mission. This is very close to the
Skylab plus Apollo CSM model. This model works, and has the added benefit
of requiring a higher flight rate, which works to lower per flight costs.

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

Rand Simberg wrote:

On Tue, 14 Sep 2004 03:21:30 GMT, in a place far, far away, Scott
Lowther made the phosphor on my
monitor glow in such a way as to indicate that:

If you're going to count this problem against the SRB, you have to be fair
and count it against any launcher being considered for CEV.

I suspect what Rand will *eventually* get around to is dropping vague hints
that what he's *really* after is some privately developed fully reusable
craft, and anything else is a horrendous waste of time and money.

Why hint? I said it quite clearly and explicitly in my essay in The
New Atlantis.

You are going to have to wait for a billionaire to actually get some
vision. Gates doesn't have it. Oprah just gave her entire studio
audience new cars. They literally have no idea after they buy the things
they want what to do with all the money.



--
"The rabbits became strange in many ways, different from other rabbits.
They knew well enough what was happening. But even to themselves they
pretended that all was well, for the food was good, they were protected,
they had nothing to fear but the one fear; and that struck here and
there, never enough at a time to drive them away. They forgot the ways
of wild rabbits. They forgot El-ahrairah, for what use had they for
tricks and cunning, living in the enemy's warren and paying his price?"
-+ Richard Adams, "Watership Down"

On Tue, 14 Sep 2004 17:18:14 -0700, in a place far, far away, "Bill
Bonde ( ``Soli Deo Gloria'' )" made the
phosphor on my monitor glow in such a way as to indicate that:

I suspect what Rand will *eventually* get around to is dropping vague hints
that what he's *really* after is some privately developed fully reusable
craft, and anything else is a horrendous waste of time and money.

Why hint? I said it quite clearly and explicitly in my essay in The
New Atlantis.

You are going to have to wait for a billionaire to actually get some
vision.

It won't take a billionaire.

Compared to an in-line SRB based ELV with a large brand-new upper
stage, Delta
III was a modest evolution, but turned in a 66% failure rate.


After only three flights - far too few to make a reliability
comparison. But all rocket designs, whether new or old, are
susceptible to failure. I was eyewitness to a Delta failure
once.


The chance of a launcher as reliable as the Delta II having two back to back
failures in three flights is greater than zero, but very small. The most
plausible conclusion is that Delta III, on the flights that it flew, was a
great deal less reliable.

Nothing surprising about that. While all rocket designs are vulnerable to
failure, all things being equal rockets with a lot of flight experience do
better than entirely new designs. Designs that have some heritage experience
fall somewhere in between, depending on how similar they are to the vehicle
they inherit from.

In the case of an in-line SRB based launcher with a new upper stage, you are
changing the configuration, aerodynamics, flight profile, upper stage and
payload. The SRB may need more control authority, since the SSMEs will no
longer help steer. You will probably need to add thrust termination ports, with
associated pyrotechnics and new failure modes. It's not quite a new vehicle,
but it's pretty close

An equaly serious objection: the US launcher market can barely
support two
launchers in that payload range. Three woud be even tougher
economics.


The economics are already tough. Both EELVs are already
government supported, having failed to be commercially
competitive with Proton, Zenit, or Ariane. If NASA can
do it cheaper with its own design, shouldn't it?


- Ed Kyle

If the design is really cheaper, then Thiokol should build it. If it is willing
to put up as much of its own money as Lockmart and Boeing have already done,
then let them build it and bid for launches.

Will McLean