Delta V Heavy as a manned launch vehicle?

In all the new images from Boeing they show a delta V heavy as the launch
vehicle of choice for the CEV. Since the delta V heavy has no propellant
crossfeed it has no engine-out capability whatsoever. So even a single
engine failure very late in the ascent profile would be enough to have to
abort the mission. In theory this should be survivable for the crew since
they have an escape tower, but there is a very large amount of unnessecary
risk and costs involved.

I think the problem of engine-out survivablilty is why spacex dropped their
original plans of using three falcon first stages for a falcon heavy. Their
current medium offering falcon V has five engines arranged in a circle,
which gives very good engine out capability as long as the engine does not
fail catastrophically and IMHO makes much more sense.

Why does boeing think that they can manage this risk? Are they planning to
add propellant crossfeed to the delta V heavy, or are they just taking the
risk to find a justification for delta V heavy? If they start taking
unnessecary risk so early in the program, that is not a good sign for the
whole concept. What's next? Adding solids to delta V heavy to cope with
weight growth?

s/Delta V/Delta IV/

"Ruediger Klaehn" wrote in message
...
In all the new images from Boeing they show a delta V heavy as the launch
vehicle of choice for the CEV. Since the delta V heavy has no propellant
crossfeed it has no engine-out capability whatsoever. So even a single
engine failure very late in the ascent profile would be enough to have to
abort the mission. In theory this should be survivable for the crew since
they have an escape tower, but there is a very large amount of unnessecary
risk and costs involved.

I think the problem of engine-out survivablilty is why spacex dropped
their
original plans of using three falcon first stages for a falcon heavy.
Their
current medium offering falcon V has five engines arranged in a circle,
which gives very good engine out capability as long as the engine does not
fail catastrophically and IMHO makes much more sense.

Why does boeing think that they can manage this risk? Are they planning to
add propellant crossfeed to the delta V heavy, or are they just taking the
risk to find a justification for delta V heavy? If they start taking
unnessecary risk so early in the program, that is not a good sign for the
whole concept. What's next? Adding solids to delta V heavy to cope with
weight growth?


I think we should be quitting all hydrogen/oxygen propellent methodologies
for launching orbit/space vehicles. The cost is just ridiculous, the
fuel/payload
weight ratio is a nonsense and its outdated human rocket technology. It
makes
spaceflight an exclusively expensive endeavour which just makes big bucks
for non innovative reasearch.

This is what we need:

http://www.isr.us/ISRHome.asp
or
http://www.liftport.com/


These are both theoretically doable; they just need the money
and commitment. Even if these elevators are not ready til
2025, its time to get going on these concepts now.

On Mon, 26 Jan 2004 14:02:47 +0000 (UTC), "Dolores Claman"
wrote:

I think we should be quitting all hydrogen/oxygen propellent methodologies
for launching orbit/space vehicles. The cost is just ridiculous,

It is high, but if there was a cheaper open, then everyone would be
using it. Obviously there is not, because they are not.

the fuel/payload weight ratio is a nonsense

That is what rocket technology is all about.

and its outdated human rocket technology.

Funny how it is so popular because it works.

It makes spaceflight an exclusively expensive endeavour which just
makes big bucks for non innovative reasearch.

They tend more to work on things that can be achieved.

This is what we need:

http://www.isr.us/ISRHome.asp
or
http://www.liftport.com/

The great space elevators.

These are both theoretically doable; they just need the money
and commitment.

They also need carbon nanotubes on a scale that is currently not
possible. Sure there is much progress in this area, but making a
carbon nanotube thread tens of thousands of kilometers long is far
from easy.

Even then this thread this need to be taken into orbit and trailed out
using rockets on either end at incredible speed. Then lets not forget
that you need many more carbon nanotube threads tens of thousands of
kilometers long in order to thicken this structure into a usable
cable.

None if this is currently possible, because carbon nano-tube
technology is not yet developed well enough.

Even when it is this would be an humongous project, which can easily
fail due to a flaw in your long thread, rockets going off course, or
just something unexpected taking it out.

And even if you had your space elevator, then don't forget that you
have to travel at mach 27 just to get on it! I would personally like
to see that one happen, but that is an entire technical leap in
itself.

Even if these elevators are not ready til
2025, its time to get going on these concepts now.

The concepts have already been completed, when they know how to build
their space elevator. And should you look into the field of carbon
nanotubes, then you will see that there is progress being made here
all the time.

Maybe one day it will actually happen, but it is extremely difficult
and would also make a wonder of the world should it prove its worth.

Cardman
http://www.cardman.com
http://www.cardman.co.uk

Dolores Claman wrote:

[snip]
This is what we need:

http://www.isr.us/ISRHome.asp
or
http://www.liftport.com/


These are both theoretically doable; they just need the money
and commitment. Even if these elevators are not ready til
2025, its time to get going on these concepts now.

Tethers in space are a very good idea, but we need to walk before we can
run. So I think that the concepts presented on www.tethers.com are much
better. They could be built today without exotic materials like carbon
nanotubes.

Read this paper to see what I mean: http://www.tethers.com/papers
MXERJPC2003Paper.pdf. This could be built with todays launch vehicles
(they are planning to use Sea Launch) and todays materials.

"Dolores Claman" wrote in message ...

I think we should be quitting all hydrogen/oxygen propellent methodologies
for launching orbit/space vehicles. The cost is just ridiculous, the fuel/payload
weight ratio is a nonsense and its outdated human rocket technology. It makes
spaceflight an exclusively expensive endeavour which just makes big bucks
for non innovative reasearch.

This is what we need:

http://www.isr.us/ISRHome.asp
or
http://www.liftport.com/

These are both theoretically doable; they just need the money
and commitment. Even if these elevators are not ready til
2025, its time to get going on these concepts now.


No, they *don't* just need the money! They need a few technological
break-throughs. *Rockets* just need the money. Rockets we could just
pay for. This one needs a "Eureka!" and *then* a big wallet.

I agree with you that this would revolutionize space flight as we know
it, but you need tens of thousands of kilometer-long intertwined nano-
tubes for a space elevator rope. Right now we can produce some nano-
tubes that are a few centimeters long.

Maybe this development will take quantum leaps, like the microchip,
and in only ten years from now it may be just a question of money.
But right now it's SCIENCE FICTION.

We should aggressively sponsor it, so promising does it look! But so
long as I don't see so much as a meter-long piece of a space-elevator-
strength tape I say, "right here and now it's impossible to do!" If
we want to guarantee being able to go to the Moon or elsewhere we bet-
ter have a few big rockets ready for that!


I would *love* to see SEs happen, though--the sooner, the better!



--
__ “A good leader knows when it’s best to ignore the __
('__` screams for help and focus on the bigger picture.� '__`)
//6(6; ©OOL mmiv :^)^\\
`\_-/ http://home.t-online.de/home/ulrich....lmann/redbaron \-_/'

"Cardman" wrote in message ...
On Mon, 26 Jan 2004 14:02:47 +0000 (UTC), "Dolores Claman"
wrote:

And even if you had your space elevator, then don't forget that you
have to travel at mach 27 just to get on it! I would personally like
to see that one happen, but that is an entire technical leap in
itself.

Well, no! Provided the technology is developed for making enough na-
notube tape to wrap around the Earth you could build a geosynchronous
space elevator. It would be anchored up in GEO, with a counterweight
easily reaching out as far as three times as high--centrifugal force
increases only linearly with distance--and on the other end near the
equator on Earth's surface.

No problem there, other than costs, if they can ever make it. But I
want to see a 1m nanotube rope, then a 1km, and then a 100km-long one
before I believe in the feasibility of a 36,000km-long one!



--
__ "A good leader knows when it's best to ignore the __
('__` screams for help and focus on the bigger picture." '__`)
//6(6; ©OOL mmiv :^)^\\
`\_-/ http://home.t-online.de/home/ulrich....lmann/redbaron \-_/'

In article ,
Ruediger Klaehn wrote:
In all the new images from Boeing they show a delta V heavy as the launch
vehicle of choice for the CEV. Since the delta V heavy has no propellant
crossfeed it has no engine-out capability whatsoever.

Neither did Mercury or Gemini's launch vehicles. Even the Saturn V had
only limited engine-out capability -- it could usually survive an engine
failure, but only in particularly favorable cases could it complete the
mission with an engine out.

If a liquid-fuel engine starts properly, it usually keeps running. The
risk is fairly small.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

Cardman wrote in
:

And even if you had your space elevator, then don't forget that you
have to travel at mach 27 just to get on it! I would personally like
to see that one happen, but that is an entire technical leap in
itself.

The whole point behind a space elevator is that the bottom end of the
elevator is fixed with respect to the ground. Getting on is little
different from getting into an elevator.

--
Coridon Henshaw - http://www3.telus.net/csbh - "I have sadly come to the
conclusion that the Bush administration will go to any lengths to deny
reality." -- Charley Reese

On 2004-01-26, Ruediger Klaehn wrote:

In all the new images from Boeing they show a delta V heavy as the launch
vehicle of choice for the CEV.

I wouldn't call most if any of those images new, I'm pretty certain that
I've seen them before. Delta-IV Heavy happens to be the largest of the
Delta IV family, so it's logical they'd showcase it on their viewgraphs.

I think the problem of engine-out survivablilty is why spacex dropped their
original plans of using three falcon first stages for a falcon heavy. Their
current medium offering falcon V has five engines arranged in a circle,
which gives very good engine out capability as long as the engine does not
fail catastrophically and IMHO makes much more sense.

Falcon V also has (will have) a payload capacity closer to a Delta II than
a Delta IV. I can't see a CEV launching on a Falcon V

Why does boeing think that they can manage this risk? Are they planning to
add propellant crossfeed to the delta V heavy, or are they just taking the
risk to find a justification for delta V heavy?

USAF want the Delta-IV Heavy to replace the Titan IV which is being
retired.

If they start taking unnessecary risk so early in the program, that is
not a good sign for the whole concept.

Delta IV was not originally designed to be man rated. Man-rating it (and
any mods required to do so) would have had to be part of the OSP programme
as I understand it, and I assume this will be part of the CEV requirements

What's next? Adding solids to delta V heavy to cope with
weight growth?

Highly unlikely, the Strap-On CBC's block the mounting points for the
Solids on the core vehicle. Boeing already have plans to upgrade the
upper stage to increase payload. There have been a number of suggestions
and discussions in this newsgroup as to 'Super' or 'Mega' Heavy versions.

Additionally, don't forget the Delta IV Heavy already has the capacity
of the Saturn-1B.


All the Best

Iain