Drive on Opportunity

"bob haller" wrote in message
...


so you admit you dont read my links, most of which come from nasawatch
or spaceflight now, both respected websites.....

You're correct. Since again, they are mostly fluff pieces.

a closed mind knows little and wouldnt investigate futher........


Take your own advice Bob.

Seriously.

And start reading real RESEARCH.

Have you read the CAIB yet?

BTW, since you seem fascinated by disasters, there are some good books to
read.

Sitting in front of me for example is Charles Perrow's Normal Accidents.
Good discussion on why complex systems are prone to accidents. He has a
follow up book (not right in front of me, so title is escaping me) which
discusses how to decouple failure modes and make things less likely to occur
and if they do occur, minimize the scope.

I'm also reading "Engineering is Human" (Henry Petroski). You'd like that.
It discusses how and why engineers make mistakes. (it's old enough, that
it's covering in part the Kansas City, MO hotel sky bridge collapse.)
Engineers are NOT perfect. They do make mistakes. But they're also
generally VERY good at what they do (and in some ways even better now than
30 years ago).

I'd recommend reading it.





--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

"bob haller" wrote in message
...


well most on the planet can still look and go outdoors.even in
antartica

Which doesn't help the folks on boomer patrol.


of course there are supermax prisoners who live in constant solitary

Yes, keywords there are "constant solitary confinement". We KNOW lack of
human interaction is a problem.
Hence, no one is suggesting locking astronauts in their bunks for months at
a time.


confinement with not even a window to the outdoors.... superrmax in
florence colorado has no windows and prisoners arent ever allowed
outdoors. out of cell just one hour a day shackled in exercise oom not
much larger than their cell

mental illness is normal for them..........

a close friend worked on shemya alaska a tiny island watching for
incoming russian bombs..... a GE contractor norad job

1 mile by 3 miles in isolation, in the begining no tv...... miserable
weather

one time they put up a tv antenna in the middle of a 40 foot military
dish that was out of service to try to get some tv. it worked if the
weather was right

he reported most of the workers were wierd........ but very well paid

now add being so far from earth, no chance for outside help in a
emergency, locked in a small space with 6 or 8 others...


And I know several folks who would do just fine there. Are there selection
criteria to take into account?
Of course. No one is suggesting otherwise.

Might we observe some behaviors we're not expecting? Possibly. But again,
this is not an area of complete unknowns.


human factors cant be dismissed.

No one is dismissing them. Someone is most likely over-hyping them.

while 40 days each way might be a piece of cake, 6 months each way
might cause serious mental issues.

people under stress may not follow all procedures just right and cause
what could easily be a devastating accident

Yes. This is called "a car accident". Don't drive.

Again, I really wonder how much experience you really have in this area?

People who are trained actually under moderate levels of stress PERFORM
BETTER. Their training kicks in and they know what to do.
You don't send untrained folks.





--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

"Jeff Findley" wrote in message
...

Sounds like something that could be done with a smallish LEO tech
demonstration mission. Perhaps fly it as a "tag-along" mission inside
the Dragon Trunk and deploy it in LEO before rendezvous and docking with
ISS.

Like I say,I think doing something like this in LEO vs say cis-lunar space
may introduce some issues due to gravity gradient. But again, no deep-space
work really be done.


But this doesn't support Bob's assertion that we need to fly these sorts
of missions well beyond LEO.


Agreed. And like I say, the other option, fixed truss. "Keep it simple"

Heck, in general I think some research into long-term rotating space
structures may be worthwhile.


Jeff

--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

"bob haller" wrote in message
...

http://www.space.com/8009-rocket-eng...s-40-days.html

just one article travel time cut to 40 days........


Great, if and when they build one.

Again, I'll point you to the details that Fred pointed out:


A mission trajectory study estimated that a VASIMR-powered spacecraft could
reach the red planet within 40 days if it had a 200 megawatt power source.

Note the ISS has 100 kw of power.

So if you want to go solar, you need 2,000 as much in terms of solar power.

Ok, that's a non-starter.

So now we're talking nuclear.

I believe Topaz-II is the largest space nuclear reactor actually flown.

I can't find much details, mass appears to be about 1 tonne. If I scale up
from the Topaz-I reactor, I get about 15kw.

But let's make the math simpler and help your argument and get 20kw out of a
reactor and that we can scale it in a linear fashion.

So now we're talking 1000 of them. Or 1000 tonne. If we're flying Falcon
9, we're talking 6-10 tonnes to LEO. To GTO even lower (2-7).

Let's go with 6 because we'll have supporting hardware, shielding, etc.

That's 166 Falcon 9 launches.

From Wikipedia again:
As of March 2013, Falcon 9 launch prices are $4,109 per kilogram ($1,864/lb)
to low-Earth orbit when the launch vehicle is transporting its maximum cargo
weight.

So, $4,109,000/tonne, at 1000 tonnes, just to launch your reactor for
VASIMR is $4,109,000,000. If I didn't skip a 0, that's $4B.

And that's assuming you can scale VASIMR and scale your reactors (I actually
suspect the reactor will scale in less than linear fashion, so that helps
your case, which needs it.) And note, that's JUST the reactors, not VASIMR
or the rest of your space ship.

Oh wait, sorry, I think I did slip a zero. You need 10,000 of them. But
tell you what's assume we can make the reactor 10x more powerful. Just to
help your case.

If I have Zubrin's numbers right, first crewed landing requires about 250
tonnes. That's 1/4 of the optimistic number I gave you.
Now, let's assume he's TOO optimistic and we double everything. We're now
talking 500 tonnes. That's about $2B. That's half the price for you flying
VASIMR. And honestly, most of his stuff is close to off the shelf. So I
don't even have to design much.

But in case you're worried, I'll toss in a long duration deep-space mission
to an NEA for an extra $1B. I'm still cheaper than your VASIMR idea.

And not I had to give you a 10x improvement factor in reactor design to come
close.

Now I'm sure if I screwed up the math Jeff or Fred or someone will correct
me.

But see, there's part of the difference. I HAVE MATH. It's even grade school
level. Let's see yours.








--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

In article 06486f17-be91-4818-8039-9e5b47dd54f2@
5g2000yqa.googlegroups.com, says...

http://www.space.com/8009-rocket-eng...s-40-days.html

just one article travel time cut to 40 days........

From the above article:

I need more power!

A mission trajectory study estimated that a VASIMR-powered
spacecraft could reach the red planet within 40 days if it
had a 200 megawatt power source. That's 1,000 times more
power than what the current VASIMR prototype will use,
although Ad Astra says that VASIMR can scale up to higher
power sources.

The real problem rests with current limitations in space
power sources. Glover estimates that the Mars mission
scenario would need a power source that can produce one
kilowatt (kW) of power per kilogram (kg) of mass, or
else the spacecraft could never reach the speeds
required for a quick trip.

Existing power sources fall woefully short of that ideal.
Solar panels have a mass to power ratio of 20 kg/kW.
The Pentagon's DARPA science lab hopes to develop solar
panels that can achieve 7 kg/KW, and stretched lens
arrays might reach 3 kg/KW, Glover said. That's good
enough for VASIMR to transport cargo around low-Earth
orbit and to the moon, but not to fly humans to Mars.

Ad Astra sees nuclear power as the likeliest power source
for a VASIMR-powered Mars mission, but the nuclear reactor
that could do the job remains just a concept on paper.
The U.S. only ever launched one nuclear reactor into space
back in 1965, and it achieved just 50 kg/kW.

In other words, *if* VASMIR can be scaled up to provide the necessary
thrust for a manned Mars mission, there is currently *no* power source
available which would meet the required output of one kW per kg of power
source mass.

In other words, this is yet another research project that might,
someday, prove useful, but it's not quite there yet. And no one has a
clue what could possibly power it anyway, even if it did exist.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

"Jeff Findley" wrote in message
...

In article 06486f17-be91-4818-8039-9e5b47dd54f2@
5g2000yqa.googlegroups.com, says...

http://www.space.com/8009-rocket-eng...s-40-days.html

just one article travel time cut to 40 days........

From the above article:

There you go interjecting facts into the discussion.

Of course I'm reminded of an old sci-fi story I need to find again. General
synopsis, scientist wants to study fusion, so designs spaceship that can
orbit the sun closely. To do this he needs to develop basically a super
efficient heat-transfer engine to his ship won't burn up. Spends a few years
studying the sun. Gets back to Earth to discover everyone with flying cars,
etc. He wonders who figured out fusion. Turns out no one. But his
heat-transfer engine was so efficient that the thermal gradient between the
top/bottom of the flying cars was enough give the power to fly. (or
something like that, forget the exact details.)

My point being, if you can figure out 1kw/kg.

(and I'll take Bob's number from earlier of 40 minutes but round up to 1
hour)

So (and again check my math) 1MJ = .28kWh.

So 1 kWh = 3.57MJ.

Now we're talking 200 megawatts.

Or 714,285 MJ

That's a hell of a lot of energy in any form.




I need more power!

A mission trajectory study estimated that a VASIMR-powered
spacecraft could reach the red planet within 40 days if it
had a 200 megawatt power source. That's 1,000 times more
power than what the current VASIMR prototype will use,
although Ad Astra says that VASIMR can scale up to higher
power sources.

The real problem rests with current limitations in space
power sources. Glover estimates that the Mars mission
scenario would need a power source that can produce one
kilowatt (kW) of power per kilogram (kg) of mass, or
else the spacecraft could never reach the speeds
required for a quick trip.

Existing power sources fall woefully short of that ideal.
Solar panels have a mass to power ratio of 20 kg/kW.
The Pentagon's DARPA science lab hopes to develop solar
panels that can achieve 7 kg/KW, and stretched lens
arrays might reach 3 kg/KW, Glover said. That's good
enough for VASIMR to transport cargo around low-Earth
orbit and to the moon, but not to fly humans to Mars.

Ad Astra sees nuclear power as the likeliest power source
for a VASIMR-powered Mars mission, but the nuclear reactor
that could do the job remains just a concept on paper.
The U.S. only ever launched one nuclear reactor into space
back in 1965, and it achieved just 50 kg/kW.

In other words, *if* VASMIR can be scaled up to provide the necessary
thrust for a manned Mars mission, there is currently *no* power source
available which would meet the required output of one kW per kg of power
source mass.

In other words, this is yet another research project that might,
someday, prove useful, but it's not quite there yet. And no one has a
clue what could possibly power it anyway, even if it did exist.

Jeff

--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

40 days may be tough but 6 months by chemical rocket is going to be
tough too on the crew, with the time delay unable to carry on a real
time discussion....... Even a 3 month Vasmir trip time can be a big
improvement

In any case BEFORE setting out on a multi year trip to mars having
some asteroid missions or other limited deep space missions is just
common sense......

"bob haller" wrote in message
...

40 days may be tough

Damn near impossible. Do the math.

but 6 months by chemical rocket is going to be
tough too on the crew, with the time delay unable to carry on a real
time discussion....... Even a 3 month Vasmir trip time can be a big
improvement

Not really. Folks handle with time delays in conversations all the time.

Again, as another poster pointed out, folks at the South Pole have
experience with this.


In any case BEFORE setting out on a multi year trip to mars having
some asteroid missions or other limited deep space missions is just
common sense......


Again, you haven't actually given any real reasons why.

While I think trips to an NEA may be great for its own reasons, I'm not
convinced it's necessary for a Mars mission.




--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

On Jun 13, 5:02*am, Fred J. McCall wrote:
"Greg \(Strider\) Moore" wrote:





"bob haller" *wrote in message
...

40 days may be tough

Damn near impossible. *Do the math.

but 6 months by chemical rocket is going to be
tough too on the crew, with the time delay unable to carry on a real
time discussion....... Even a 3 month Vasmir trip time can be a big
improvement

Not really. *Folks handle with time delays in conversations all the time.

Again, as another poster pointed out, folks at the South Pole have
experience with this.

Hell, we had long experience with it on Usenet!



In any case BEFORE setting out on a multi year trip to mars having
some asteroid missions or other limited deep space missions is just
common sense......

Again, you haven't actually given any real reasons why.

Why, it's 'common sense'. *That means there is no reason why.

--
"Some people get lost in thought because it's such unfamiliar
*territory."
* * * * * * * * * * * * * * * * * * * --G. Behn

because we have never had a human deep space mission, we should first
do a short one before commiting a crew to a multi year one......

again its just common sense, which you obviously dont have.......

In article 091d5d69-98b6-4ecf-980f-8b832bbe93d4
@c3g2000yqj.googlegroups.com, says...

40 days may be tough but 6 months by chemical rocket is going to be
tough too on the crew, with the time delay unable to carry on a real
time discussion....... Even a 3 month Vasmir trip time can be a big
improvement

Apparently you weren't paying attention to the article *you* cited and I
quoted! Holy crap Bob. Pay attention to what *you* are citing.

Let me break it down for you:

1. VASMIR is a research project which has not yet been scaled up to the
size needed for a manned Mars mission. This is a problem yet to be
solved.

2. If #1 is solved, there is *no* power source in existence, or even on
the horizon, which can produce enough power in a tiny amount of mass in
order to make the numbers work.

Your proposed mission architecture is based on *research* in a lab,
which is *not* a viable way of actually *engineering* actual flight
hardware.

In any case BEFORE setting out on a multi year trip to mars having
some asteroid missions or other limited deep space missions is just
common sense......

B.S. You have yet to provide believable examples of why this is useful,
especially since the conditions on an asteroid are *nothing* like the
conditions on Mars.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer