Military vs Civilian Orbital Laboratories, Vehicles, and Crews

Jeff Findley wrote:
"Pat Flannery" wrote in message
...

Check out these two projects:
http://www.astronautix.com/articles/prorizon.htm
That's the Army one.


From above:

For the return to earth, from either the earth orbit or the
lunar surface, aerodynamic braking will be used, since it
allows significant overall payload increases when compared
to rocket braking. The aerodynamic braking body used for this
study is similar in shape to a JUPITER missile nose cone
modified by the addition of movable drag vanes at the base of
the cone.


I think they are overlooking the G loads they are going to get unless
they do a lifting type reentry.

...and: http://www.astronautix.com/articles/lunex.htm
The Air Force one.


From above:

A three-man Lunex Re-entry Vehicle. This vehicle must be
capable of re-entry into the earth's atmosphere at velocities
of 37,000 ft/sec. It must also be capable of making a
conventional aircraft landing.

Definitely an Air Force bias here as to the landing method. ;-)


In that case trying to build a aerodynamic vehicle to enter the
atmosphere is going to be very challenging.
Dyna-Soar was pretty cutting edge without demanding that it enter the
atmosphere at lunar return velocities.
Even today that would be a very challenging requirement to meet.
Both of these plans were very blue sky in regards to both technology and
timeline.
The big question is of course what military use the lunar base serves.
Its way to far away to do reconnaissance from, and any missile launched
toward Earth from it will take well over a day to reach its target even
with a very large booster.
Then there's the problem of the guidance system for the warhead.
I assume this is supposed to be some sort of a revenge weapon in case of
a surprise Soviet nuclear attack, so there will be no US infrastructure
left to give it trajectory updates on the way in, so it will have to use
either updates from the Moon or a inertial system. Gyro drift over that
period of time will be significant, and it might be possible to jam
signals being sent to it from the Moon.
All in all, this is a very complex and expensive way to do a form of
deterrence that could be done far more easily and cheaply with nuclear
missile submarines.

Pat

wrote:

All wrong. The F-1 was first an USAF project and not Army
Big solids were not Army but USAF

Redstone didn't even do one payload much less 'reduce their size".


The key development that led to our liquid fueled boosters and missiles
was the North American "Navaho" missile project.
Its booster engines became the forefathers of those on Thor, Jupiter,
and Atlas.
It's odd that von Braun's team stuck with LOX as a missile propellant
for so long.
Even in WW II, the German army was looking to replace the V-2's
propellants with storable hypergolics due to the problems LOX posed to
its deployment with the need to fuel the missile with it just before
liftoff, and the boil-off problems during transport of the LOX from the
factory to missiles in the field.
The Soviets went over to storable propellants as soon as they could,
with their first "real" ICBM, the R-16/SS-7 "Saddler" using them, as
well as their IRBMs, LRBMs, and SLBMs.
They had such success with them that it seriously impeded their work on
large scale solid fueled rocket motors and they ended up lagging around
a decade behind the US in that technology.

Pat

Bash wrote:
And a possibly interesting issue for the heatshield if it was to be
reusable. Unobtainium anyone? ;-)


I suspect the only way to do it would be some sort of ablative
heatshield you'd jettison after reentry leaving the vehicle light enough
to glide land.

wrote:
You are insane.

Seek help.


You know, it would help if you told us who you were referring to.
I'm betting it's Brad Guth, but that's just a inspired guess based on
what he normally writes. :-)

Pat

wrote:
You are delusional.

Don't post until you get professional help.


Guth again, right? :-D

Pat

On Mar 15, 9:05*am, (Rand Simberg)
wrote:
On Sat, 15 Mar 2008 02:24:17 -0600, in a place far, far away, Pat
Flannery made the phosphor on my monitor glow in
such a way as to indicate that:



wrote:
You are delusional.

Don't post until you get professional help.

Guth again, right? :-D

It's hard to tell around here. *There are lots of suspects. *He could
even be talking to himself.

Rand, when you're not spouting evil bull****, you're spouting nasty
bull****. That causes me to suspect you probably aren't very popular
with the ladies! lol.

Pat is correct, I'm responding to something Guth said. lol.

On Mar 14, 8:12*pm, Bash wrote:
From above:

* *A three-man Lunex Re-entry Vehicle. This vehicle must be
* *capable of re-entry into the earth's atmosphere at velocities
* *of 37,000 ft/sec. It must also be capable of making a
* *conventional aircraft landing.

Definitely an Air Force bias here as to the landing method. *;-)

Jeff

And a possibly interesting issue for the heatshield if it was to be
reusable. *Unobtainium anyone? ;-)

Warheads re-entered at nearly orbtial velocity. The design of re-
entry vehicles - RV - is STILL highly classified! It was 'above top
secret' back in the day. The whole concept that re-entry is an
impossibility and you need special stuff and its too complicated and
dangerous for mortal man - was developed at that time as a barrier to
that knowledge base, and those ideas are still around - as reflected
in your statement.

Bluff body re-entry vehicles create a compression wave well in front
of the body itself, causing the bulk of the heating to occur in the
air removed from the surface of the vehicle, and then to move that
air sideways into the slip stream. The body itself is coated with an
ablative layer - the simple observation that is oft-repeated from
those who worked in the field in that era - was a wax coated milk
carton. You could put it in a fire, and the carton would not burn
until the wax had all evaporated from the cardboard. Another simple
observation is to hold a paper cup filled with water over a candle.
An empty paper cup burns, the water removes heat fast enough to
control the temperature rise and you never reach combustion
temperatures, even though the gas from the candle flame is well above
those temperatures (451F) So, a bluff body that creates a shock,
coated with an ablative layer of material, made out of aluminum -
works just dandy.

Since forces are a produce of air density and velocity squared,
controlling the angle of descent determines body forces and those
along with vehicle density determine acceleration forces - which gives
you the structural requirements - once you have the thermal
requirements figured out.

So, a low density vehicle - such as a booster rocket, required lower
entry angles to recover than a high density vehicle - like a nuclear
weapon. .

On Sat, 15 Mar 2008 02:24:17 -0600, in a place far, far away, Pat
Flannery made the phosphor on my monitor glow in
such a way as to indicate that:



wrote:
You are delusional.

Don't post until you get professional help.


Guth again, right? :-D

It's hard to tell around here. There are lots of suspects. He could
even be talking to himself.

On Mar 14, 4:49*pm, wrote:
You are delusional.

Don't post until you get professional help.

This coming from our green hydrogen guy that can't manage to get one
cent of public DOE support for what should work as good or better than
most other renewable energy alternatives, much less deliver one
prototype tonne of such green hydrogen. Way to go willie.moo.
. - Brad Guth

wrote:
It's hard to tell around here. There are lots of suspects. He could
even be talking to himself.


Rand, when you're not spouting evil bull****, you're spouting nasty
bull****. That causes me to suspect you probably aren't very popular
with the ladies! lol.

Oh, don't get him started on that; according to his descriptions he's
the greatest cocksman since Casanova. :-D

Pat