Questions about "The High Frontier"

Hop David wrote:


NASA did a study on this to determine the minimum diameter of a
rotating station where the crew wouldn't feel dizziness as they moved
around in it due to the perception of what "up" was, particularly in
regards to their inner ear.
IIRC, it was around 400 feet diameter for a 1g station.

Pat


400 feet = 122 meters, so the radius would be 61 meters.

w^2 * 61 meters = 9.8 meters/sec^2

w^2 = 9.8/61sec^2

w = .4 radians/sec = 3.8 RPM


Based on its rotational rate in the movie, I wonder how big the 2001
station was?
You could actually exactly figure out its size based on its RPM.

Pat

Pat Flannery wrote:

Seriously, remember how we were gong to get to the Moon? Reusable ferry
rockets were going to build this space station, and then cargo rockets
were going to bring up propellants and parts to make a Moonship...

People sometimes forget that those "reusable ferry rockets" were
themselves going to be on-beyond-Saturn beasts -- 15M lbs GLOW, if I
remember correctly from Jenkins.

Von Braun took for granted there'd be a good metal-skin TPS solution
(which we didn't have in time for the Shuttle, and don't have today).
Given reasonable development time for that, and the time needed just
to get such beasts flying reliably enough to start building the Big
Wheel Station...

It's easy for people say confidently "We should have gone the
systematic von Braun route instead of the quick & dirty ELV route."
But it's not clear to me that they understand the much longer timeline
it implied.

Pat Flannery wrote:

NASA did a study on this to determine the minimum diameter of a
rotating station where the crew wouldn't feel dizziness as they moved
around in it due to the perception of what "up" was, particularly in
regards to their inner ear.
IIRC, it was around 400 feet diameter for a 1g station.

400 feet = 122 meters, so the radius would be 61 meters.

w^2 * 61 meters = 9.8 meters/sec^2

w^2 = 9.8/61sec^2

w = .4 radians/sec = 3.8 RPM

Based on its rotational rate in the movie, I wonder how big the 2001
station was?
You could actually exactly figure out its size based on its RPM.

Not unless you agree on the g level provided at the outer ring :-)

According to http://grin.hq.nasa.gov/ABSTRACTS/GPN-2003-00093.html

"Kubrick's station in the movie was 900 feet in diameter, orbited 200
miles above Earth, and was home to an international contingent of
scientists, passengers, and bureaucrats."

According to http://members.tripod.com/Aries_1B/id66.htm

it was 600-feet wide, rotated at 1.3 RPM, and generated 0.18g at the
outer ring.

Was there mention in the book as to whether the Station provided earth
or lunar gravity levels?

--
Dave Michelson

Erik Max Francis skreiv:
John Schilling wrote:

If you want to skip the fluid mechanics, just tack a factor of one-half
on the "area of hole times density of air times speed of sound" BOTE
calculation.

So what's the full calculation, then?

http://www.sff.net/people/geoffrey.landis/higgins.html

Already mentioned in this thread.


Eivind Kjørstad

Matthias Warkus skreiv:

Uh, yes. All forms of power generation need a distribution grid and
buffer storage of some kind. Your point being?

Solar needs *more* buffer-storage than many (not all) other forms of
power-generation.

Accidentally, that makes it a perfect match for some other types of
power-generation that has huge buffer-stores.

For example we produce 90%+ of our electrical energy with hydro-power
that has water-magazines in the high mountains with capacity measured
literally in *months*. Needs to be so, since rainfall and snowmelt ain't
really adjusted to fit power-consumption.

Solar is a perfect match. You use solar whenever the sun shines, and
whenever it doesn't, you use the cubic kilometres of water stored at
altitude.

The stores are cheap (building a 10m dam on a 20km^2 lake at 1000m
stores 540Mwh, drilling a drainpipe so you'll be able to drain the lake
to 10 meter below pre-dam levels doubles that to 1Gwh. A larger lake
stores more energy, at no extra construction cost. The store is close to
maintenance-free for several decades.

In total we store aproximately 90.000Gwh this way, a normal year
consumes aproximately 110.000Gwh, so if the batteries where all charged
up (currently quite close, 94%) we'd have enough for pretty much a year,
even if no drop of water would fall and no drop of ice/snow would melt.

Okay, so Norway is special. Thing is though, we're hooked up, so that
battery buffers not only our production/consumption, but also Swedens,
Denmarks, Finlands, and to some degree even Germanys.

There's other places in the world with mountains and rainfall. In a
pinch you can do with only mountains, and use active -pumping- on
surplus days to offset days with high demand and low production. Modern
turbines and pumps are efficient, I've seen experiments that achieve 75%
roundtrip efficiency.


Eivind Kjorstad

Monte Davis wrote:
Pat Flannery wrote:


Seriously, remember how we were gong to get to the Moon? Reusable ferry
rockets were going to build this space station, and then cargo rockets
were going to bring up propellants and parts to make a Moonship...


People sometimes forget that those "reusable ferry rockets" were
themselves going to be on-beyond-Saturn beasts -- 15M lbs GLOW, if I
remember correctly from Jenkins.


I've got all the goodies on them from one of his books, hoards of
Hydrazine/RFNA engines with pretty poor isp.
What's really impressive is what happens as stage two gets ready to burn
out...excuse me....undergoes brenschluss...
At that point the crew are experiencing 8 g's.
That's impressive on the way down, on this trip, you get it on the way up.
You could certainly do it, but no weaklings need apply. :-)

Von Braun took for granted there'd be a good metal-skin TPS solution
(which we didn't have in time for the Shuttle, and don't have today).
Given reasonable development time for that, and the time needed just
to get such beasts flying reliably enough to start building the Big
Wheel Station...


Until they actually figured out how reentering bodies decelerated and
heated in the upper atmosphere at over Mach 20, it was all talking
through your hat.

It's easy for people say confidently "We should have gone the
systematic von Braun route instead of the quick & dirty ELV route."
But it's not clear to me that they understand the much longer timeline
it implied.

Oh come on! We could have been on the Moon by 1963!
I've got $300.00 down with this guy in Australia that says so.
BTW...the scene of the Antipodal Bomber being pulled out of the hangar
is great, but just like "The Two Towers" rose or fell with the Ents (it
rose...oh yes, it rose), the takeoff scene of the Antipodal Bomber is
the critical thing.
He does that right, and it's going to be like a "burp gun loaded up with
full-auto kickass Nazi handjobs" as Neill Cumpston would say. :-)

Pat

Pat Flannery wrote:

BTW...the scene of the Antipodal Bomber being pulled out of the hangar
is great, but just like "The Two Towers" rose or fell with the Ents
(it rose...oh yes, it rose), the takeoff scene of the Antipodal Bomber
is the critical thing. He does that right, and it's going to be like a
"burp gun loaded up with full-auto kickass Nazi handjobs" as Neill
Cumpston would say. :-)
Pat

For anyone who doesn't know what I'm talking about; Neill Cumpston's
review of "300":
http://www.aintitcool.com/node/31520
Within one week of him writing this, the word "dude-ity" had become a
permanent part of the English language, and was showing up all over the
web and on TV.
Since "Deathproof" just came out on DVD, you might want to read his
review of "Grindhouse" also:
http://www.aintitcool.com/node/32030
In fact, look all of his reviews up if you have a half-hour or so to
spare per review, because that's about how long it's going to take to
get over the cramps in your sides from laughing that hard.
Just fukin' neill. :-D :-D :-D

Pat

Dave Michelson wrote:

Not unless you agree on the g level provided at the outer ring :-)

According to http://grin.hq.nasa.gov/ABSTRACTS/GPN-2003-00093.html

"Kubrick's station in the movie was 900 feet in diameter, orbited 200
miles above Earth, and was home to an international contingent of
scientists, passengers, and bureaucrats."

If she's 900 feet in diameter, then she's going mighty fast on rotation
in the movie. Generating over 1 g at her outside rim makes no sense. She
looks like she doing around 4rpm in the movie and that would imply that
she's around 350 feet in diameter.
I call the station "she" because I fell head over heels in love with her
when I saw her on the screen for the first time when I was a kid.
Mind you, a Minbari Sharlin class cruiser stole my love in time, and
despite the fact of a "lost weekend" with a Incom T-65 X-Wing...but you
always remember your first love.
As to the Federation Constitution class starship NC-1701.
Well, I've put that all behind me now. Mistakes of youth must be
accepted as the wild oats we all sow, to become who we are now.
That being said... the energy and matter transparent hemispheres that
cover the front end of a Constitution class starship's Bussard intakes
seem superior in regards to gathering interstellar hydrogen from all
directions to the vertically aligned intakes of a "Enterprise" class
starship.
But she can suck on anything she wants, any way she wants, can't she?

The faithless bitch. :-)

Pat

"Hop David" wrote in message
...

Coal, petroleum and nuclear are all limited energy sources. Space based
solar also is also limited but the limit is far higher.

The uranium dissolved in the oceans would fuel current nuclear
reactors for tens of thousands of years. The uranium and thorium
in the crust could fuel breeder reactors supplying the entire
current world primary energy demand for longer than the Earth
will remain habitable. So, these sources are not limited to
nearly the same extent coal or petroleum are.

Paul

On Thu, 04 Oct 2007 19:48:08 +0200, in a place far, far away, Matthias
Warkus made the phosphor on my
monitor glow in such a way as to indicate that:

Greg D. Moore (Strider) schrieb:
"Matthias Warkus" wrote in message
...
Hop David schrieb:
Orbital structures like the proposed Bigelow hotels would be inadequate
for long stays as gravity is needed to maintain health. Crew rotations
are very expensive so you want to make them infrequent.
People have held out in zero-g space stations for more than one year
without serious health problems AFAIK.


Yes and no. Long-term stays require extensive exercise while in orbit (on
the order of 2 hours a day).

If we start to build SPS and the like, almost certainly some form of
rotating stations (or at least sleeping quarters) will be built.

I'd think it cheaper to let people live in zero-g and put two hours of
mandatory daily exercise into their contracts.

It's not clear that that's a sufficient prophylactic.