Space Travel by Humans is Possible

I learned something new from a science article on a web site today.

I remembered reading about how astronauts would have to have "storm
cellars" that were heavily shielded in case of a solar flare while
they were on a long-duration space mission.

But apparently this isn't the case. Solar flares send out protons -
which indeed are intense radiation, but of a kind that the walls of a
spaceship are sufficient to block. Only an EVA would need to be
avoided.

And, since they're accompanied by ejection of gases, cosmic ray levels
actually drop during a solar flare, so the radiation that can't easily
be blocked is reduced.

I don't remember the exact URL now, but the article noted actual
cosmic ray measurements on the ISS, and it was written by a Dr. Tony
Philips. It mentions that this phenomenon is called a "Forbush
minimum", after one Dr. Stephen Forbush. (Since this demonstrates that
the only sudden change in cosmic ray levels in space is a *decrease*,
not an *increase*, could this be the origin of Irving Forbush -
somewhat as DC had their revenge on Isaac Asimov after he wrote an
article about the implausibility of Superman's ability to fly by
having a villain in one story that looked like him? I suppose, though,
that it's just an odd coincidence, even if Dr. Stephen Forbush's
discovery did indeed predate the origin of the Fantastic Four.)

Of course, this may not solve all the problems with radiation for a
trip to Mars. While Dr. Zubrin may not think so, others have felt that
the damage caused by the cosmic ray levels experienced on a trip to
Mars is unacceptably high.

John Savard

Quadibloc wrote:
I learned something new from a science article on a web site today.

I remembered reading about how astronauts would have to have "storm
cellars" that were heavily shielded in case of a solar flare while
they were on a long-duration space mission.

But apparently this isn't the case. Solar flares send out protons -
which indeed are intense radiation, but of a kind that the walls of a
spaceship are sufficient to block. Only an EVA would need to be
avoided.

And, since they're accompanied by ejection of gases, cosmic ray levels
actually drop during a solar flare, so the radiation that can't easily
be blocked is reduced.

I don't remember the exact URL now, but the article noted actual
cosmic ray measurements on the ISS, and it was written by a Dr. Tony
Philips. It mentions that this phenomenon is called a "Forbush
minimum", after one Dr. Stephen Forbush. (Since this demonstrates that
the only sudden change in cosmic ray levels in space is a *decrease*,
not an *increase*, could this be the origin of Irving Forbush -
somewhat as DC had their revenge on Isaac Asimov after he wrote an
article about the implausibility of Superman's ability to fly by
having a villain in one story that looked like him? I suppose, though,
that it's just an odd coincidence, even if Dr. Stephen Forbush's
discovery did indeed predate the origin of the Fantastic Four.)

Of course, this may not solve all the problems with radiation for a
trip to Mars. While Dr. Zubrin may not think so, others have felt that
the damage caused by the cosmic ray levels experienced on a trip to
Mars is unacceptably high.

John Savard

The effect mentioned is at most very brief, and occurs only at the
peak of the solar maximum... After that, cosmic radiation will go on
destroying the astronaut's body.

And this is not the most dangerous problem. Besides radiation
there is the lack of gravity, that kills the astronauts in 1.5 to 2
years.

Nobody has resisted more than 1.5 years in space without gravity...
This means that artificial gravity is needed
during the whole flight, what makes the spaceship much heavier.

All this problems can be solved of course IF we develop a technology
for life supporting systems able to work in space for 4 years without
a single failure.

And THAT is the real show stopper. That technology doesn't exist today.
We have technology to resist in space for dozens of years without
problems but those are robots. For life support systems there is
several orders of magnitude reliability needed, and that will be a very
difficult development.

Until that technology exists, it is impossible to go anywhere in person.
Looking at the rate of failures in the ISS, the spaceship would be
a pile of junk after 1 year only. And we are speaking here of a
spaceship able to carry an enormous mass of oxygen/food/supplies and
what have you to sustain the astronaut's during those years in space.

Much more complicated than the ISS. The ISS needs a constant supply of
materials from earth to keep it running. All that is impossible
in a Mars trip.

And Mars is the nearest planet.

Anyway, WHY do we need to go in person?

Venus, for instance, with its 450 degrees C is a hell to live. You want
to go to venus in person?

Mercury is even worst. Jupiter with is gravity 8 times that of earth is
off limits: the astronaut couldn't survive a few hours at that gravity.
An 70 Kg astronaut would weight more than half a ton. Impossible to
sustain breathing at that gravity. Not to speak about blood circulation,
etc. The heart breaks down in a few minutes. Try to breathe with a
weight of just 250 Kg.

And so on. Humans aren't built for anything else but EARTH. We will go
eventually out of it, of course, but it will take at least a century
to develop a technology able to bring us to space.




--
jacob navia
jacob at jacob point remcomp point fr
logiciels/informatique
http://www.cs.virginia.edu/~lcc-win32

"jacob navia" wrote in message
...

And this is not the most dangerous problem. Besides radiation
there is the lack of gravity, that kills the astronauts in 1.5 to 2
years.


As a friend of mine is wont to say, "show me the pile of dead bodies."


Nobody has resisted more than 1.5 years in space without gravity...

No one has tried. And the one cosmonaut who did stay in space that long
survived just fine.

This means that artificial gravity is needed
during the whole flight, what makes the spaceship much heavier.

All this problems can be solved of course IF we develop a technology
for life supporting systems able to work in space for 4 years without
a single failure.

That's a bull**** requirement. There is no need to design a system that
will work 4 years w/o a SINGLE failure.



And THAT is the real show stopper. That technology doesn't exist today.
We have technology to resist in space for dozens of years without
problems but those are robots. For life support systems there is
several orders of magnitude reliability needed, and that will be a very
difficult development.


Why? What exactly is different? Should be easy for you to list the
differences.


--
Greg Moore
SQL Server DBA Consulting Remote and Onsite available!
Email: sql (at) greenms.com http://www.greenms.com/sqlserver.html

Greg D. Moore (Strider) wrote:
"jacob navia" wrote in message
...
And this is not the most dangerous problem. Besides radiation
there is the lack of gravity, that kills the astronauts in 1.5 to 2
years.


As a friend of mine is wont to say, "show me the pile of dead bodies."


They stopped short, I think after 1 year

Longest stay in space: Vladimir Titov and Musa Manarov spent 366 days in
space from December 21, 1987, to December 21, 1988, manning the Mir
space station.

http://www.permanent.com/s-nograv.htm

Trouble ensues upon the return to life with gravity. The rapid
deceleration during reentry is especially stressful as the apparent
gravity grows from zero to more than one "g" in a matter of minutes. In
1984, after a 237-day mission, Soviet cosmonauts felt that if they had
stayed in space much longer they might not have survived reentry . In
1987, in the later stages of his 326-day mission, Yuri Romanenko was
highly fatigued, both physically and mentally. His work day was reduced
to 4.5 hours while his sleep period was extended to 9 hours and daily
exercise on a bicycle and treadmill consumed 2.5 hours. At the end of
the mission, the Soviets implemented the unusual procedure of sending up
a "safety pilot" to escort Romanenko back to Earth.

Nobody has resisted more than 1.5 years in space without gravity...

No one has tried. And the one cosmonaut who did stay in space that long
survived just fine.


Sure sure. But 4 *YEARS* ????

Stop talking BS man.

In this article we read
http://www.medicine.mcgill.ca/mnmsmi/White%201998.pdf

After nine days in space: “It’s quite a
shock. The first time I pushed myself
up, I felt like I was lifting three times
my weight.”


AFTER NINE DAYS!

After two years the changes could be permanent, and because nobody wants
to die early for science, nobody has stayed more than a year in
space.


This means that artificial gravity is needed
during the whole flight, what makes the spaceship much heavier.

All this problems can be solved of course IF we develop a technology
for life supporting systems able to work in space for 4 years without
a single failure.

That's a bull**** requirement. There is no need to design a system that
will work 4 years w/o a SINGLE failure.


No?

Yes, if they have a failure they go to the next spaceship repair shop.
Sorry I did not realize that.



And THAT is the real show stopper. That technology doesn't exist today.
We have technology to resist in space for dozens of years without
problems but those are robots. For life support systems there is
several orders of magnitude reliability needed, and that will be a very
difficult development.


Why? What exactly is different? Should be easy for you to list the
differences.


The difference is that life support systems must go on working
continuously without any failures for 4 years. In the ISS they
can just wait till a replacement is shipped. Not so in a spaceship
in Mars or in the way to or from Mars.

The ISS is continuously resupplied from Earth.

Anyway arguing this is ridiculous. Anyone with a small interest
in this question can survey the abundant medical literature about
this and see the problems.

Lunar gravity is very week (only 50% of earth gravity). This will
preclude also missions lasting more than 1 year.


--
jacob navia
jacob at jacob point remcomp point fr
logiciels/informatique
http://www.cs.virginia.edu/~lcc-win32

On Thu, 17 Jan 2008 19:51:24 +0100, in a place far, far away, jacob
navia made the phosphor on my monitor glow in such
a way as to indicate that:


Why? What exactly is different? Should be easy for you to list the
differences.


The difference is that life support systems must go on working
continuously without any failures for 4 years. In the ISS they
can just wait till a replacement is shipped. Not so in a spaceship
in Mars or in the way to or from Mars.

No, instead you build in redundancy, and use the on-board crew to
repair them when there are failures.

The ISS is continuously resupplied from Earth.

Anyway arguing this is ridiculous. Anyone with a small interest
in this question can survey the abundant medical literature about
this and see the problems.

Lunar gravity is very week (only 50% of earth gravity). This will
preclude also missions lasting more than 1 year.

The moon is abot 16% of earth's gravity. We have zero information on
the long-term effects of this on human physiology. Stop flaunting
your ignorance here.

On Jan 17, 2:11*pm, (Rand Simberg)
wrote:
On Thu, 17 Jan 2008 19:51:24 +0100, in a place far, far away, jacob
navia made the phosphor on my monitor glow in such
a way as to indicate that:

Why? *What exactly is different? *Should be easy for you to list the
differences.

The difference is that life support systems must go on working
continuously without any failures for 4 years. In the ISS they
can just wait till a replacement is shipped. Not so in a spaceship
in Mars or in the way to or from Mars.

No, instead you build in redundancy, and use the on-board crew to
repair them when there are failures.



The ISS is continuously resupplied from Earth.

Anyway arguing this is ridiculous. Anyone with a small interest
in this question can survey the abundant medical literature about
this and see the problems.

Lunar gravity is very week (only 50% of earth gravity). This will
preclude also missions lasting more than 1 year.

The moon is abot 16% of earth's gravity. *We have zero information on
the long-term effects of this on human physiology. *Stop flaunting
your ignorance here.

Not zero, but little information about human physiology WRT to the
moon. You make it seem like we have never been there like Guth
claims...

Rand Simberg wrote:
The moon is abot 16% of earth's gravity. We have zero information on
the long-term effects of this on human physiology. Stop flaunting
your ignorance here.

Yes, I made a mistake when copying the data.

--
jacob navia
jacob at jacob point remcomp point fr
logiciels/informatique
http://www.cs.virginia.edu/~lcc-win32

On Jan 17, 1:51*pm, jacob navia wrote:
[...]
Lunar gravity is very week (only 50% of earth gravity). This will
preclude also missions lasting more than 1 year.


1/6th or .165 of earth's gravity you mean. Please be more rigorous
with your numbers. Look them up!

"jacob navia" wrote in message
...
Greg D. Moore (Strider) wrote:
"jacob navia" wrote in message
...
And this is not the most dangerous problem. Besides radiation
there is the lack of gravity, that kills the astronauts in 1.5 to 2
years.


As a friend of mine is wont to say, "show me the pile of dead bodies."


They stopped short, I think after 1 year


Exactly.

So in other words you're spewing BS, since obviously we don't know what
happens at 1.5-2 years.


Longest stay in space: Vladimir Titov and Musa Manarov spent 366 days in
space from December 21, 1987, to December 21, 1988, manning the Mir space
station.


And they returned in better shape than Romanenko partly because they learned
from his experience and as I recall, they walked away from the capsule.

Nobody has resisted more than 1.5 years in space without gravity...

No one has tried. And the one cosmonaut who did stay in space that long
survived just fine.


Sure sure. But 4 *YEARS* ????

With time spent in a gravity field in between.

The honest answer is, "we don't know for sure". But to say it kills people
is a complete inaccuracy.


Stop talking BS man.

In this article we read
http://www.medicine.mcgill.ca/mnmsmi/White%201998.pdf

After nine days in space: “It’s quite a
shock. The first time I pushed myself
up, I felt like I was lifting three times
my weight.”


AFTER NINE DAYS!

After two years the changes could be permanent, and because nobody wants
to die early for science, nobody has stayed more than a year in
space.

Nobody? Oh hell. Ask the astronauts who strap into the shuttle.
Stastitically they're shortening their lives, but they do it anyway. Many
people are willing to die early for many causes.



This means that artificial gravity is needed
during the whole flight, what makes the spaceship much heavier.

All this problems can be solved of course IF we develop a technology
for life supporting systems able to work in space for 4 years without
a single failure.

That's a bull**** requirement. There is no need to design a system that
will work 4 years w/o a SINGLE failure.


No?


No.


Yes, if they have a failure they go to the next spaceship repair shop.
Sorry I did not realize that.

No, if they have a failure, they repair it or they failover to a backup
system. But requiring not a SINGLE failure is hardly necessary.




And THAT is the real show stopper. That technology doesn't exist today.
We have technology to resist in space for dozens of years without
problems but those are robots. For life support systems there is
several orders of magnitude reliability needed, and that will be a very
difficult development.


Why? What exactly is different? Should be easy for you to list the
differences.


The difference is that life support systems must go on working
continuously without any failures for 4 years. In the ISS they
can just wait till a replacement is shipped. Not so in a spaceship
in Mars or in the way to or from Mars.

Right, they just hold their breath at ISS when things fail and wait for the
replacement.

Oh wait, no they don't. They have backups and repair procedures.


The ISS is continuously resupplied from Earth.

Anyway arguing this is ridiculous. Anyone with a small interest
in this question can survey the abundant medical literature about
this and see the problems.

Lunar gravity is very week (only 50% of earth gravity). This will
preclude also missions lasting more than 1 year.

Umm, 50%? Want to try again?

And again, you can't say what is or isn't precluded. We honestly don't
know.
1/6th gravity may be perfectly fine, it may be better than zero G, or it may
even be worse.

But w/o data we can't say for sure one way or the other.




--
jacob navia
jacob at jacob point remcomp point fr
logiciels/informatique
http://www.cs.virginia.edu/~lcc-win32



--
Greg Moore
SQL Server DBA Consulting Remote and Onsite available!
Email: sql (at) greenms.com http://www.greenms.com/sqlserver.html

jacob navia wrote:

:Greg D. Moore (Strider) wrote:
:
: No one has tried. And the one cosmonaut who did stay in space that long
: survived just fine.
:
:
:Sure sure. But 4 *YEARS* ????
:
:Stop talking BS man.
:

You've never heard of centripetal force? Stop ignoring simple
solutions to you doom and gloom, man.

:
: That's a bull**** requirement. There is no need to design a system that
: will work 4 years w/o a SINGLE failure.
:
:
:No?
:

No.

:
:Yes, if they have a failure they go to the next spaceship repair shop.
:Sorry I did not realize that.
:

Stop talking bull****, man. If they have a failure they FIX it. You
know. Run the backup equipment while they break out spare parts and
fix whatever broke.

:
: Why? What exactly is different? Should be easy for you to list the
: differences.
:
:
:The difference is that life support systems must go on working
:continuously without any failures for 4 years.
:

Hogwash. That's what backups and spare parts are for.

:
:In the ISS they
:can just wait till a replacement is shipped. Not so in a spaceship
:in Mars or in the way to or from Mars.
:

You take your spares with you, you stupid git.

:
:Anyway arguing this is ridiculous. Anyone with a small interest
:in this question can survey the abundant medical literature about
:this and see the problems.
:
:Lunar gravity is very week (only 50% of earth gravity). This will
reclude also missions lasting more than 1 year.
:

And this shows just how ignorant you are.

1) Lunar gravity is not very week. I suspect the word you're looking
for is 'weak'.

2) Lunar gravity is *NOT* "only 50% of earth gravity". It is, in
point of fact, much less than that.

3) No one knows where the 'point of no return' is for reduced gravity
exposure. You do not know that "this will preclude also missions
lasting more than 1 year". In point of fact, you do not know that one
lunar gravity isn't sufficient to allow a human being to function
indefinitely.

And so we see that you are but an ignorant liar who is bound and
determined to kill any manned space exploration.

If men aren't going, no need to send toasters. Shut down planetary
science right now.


--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson