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

On Jan 16, 11:44*pm, Quadibloc wrote:
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.)
{snip}
John Savard

This is not considering that the ISS is within the Earth's Van Allen
belt. My understanding is that travelling through that and being
outside of the Van Allen belt changed the whole solar radiation
picture.

Arthur Hansen

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

And yet even back in the 1960's NASA didn't think it was that hard to
put together a relatively lightweight lunar base that would allow stay
times of half a year or longer.

:
: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.
:

Oh, hogwash! They've never heard of centripetal force where you live?

This 'insoluble' problem is quite easy to solve. You put your life
support pod on one end of a rope. Stick your lander/supplies for the
stay on the other end. Spin for 'gravity'. The only added weight is
the tether connecting the two.

:
: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.
:

Centripetal force is pretty reliable.

:
: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.
:

So you take it with you from the start. All that requires is
planning.

:
: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
ff 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.
:

So we should cancel planetary science funding now, since it's totally
irrelevant to anything for at least a century.

:
: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.
:

You sure it's not billions and billions of years?

If I agreed with you, I'd say we should kill all planetary science
funding now as a waste of money. We can wait a century to do it.


--
"Before you embark on a journey of revenge dig two graves."

-- Confucius

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.

That is true of most passive solar events, although a good halo CME
isn't passive, and much less passive is our physically dark moon
that'll nail our frail DNA with gamma and hard-X-rays, so you want to
avoid the likes of our naked/anticathode worthy moon at all cost.

Remember that ISS is always 50% protected by Earth and still 100%
protected by our extensive magnetosphere. Also remember that most
extended EVAs are of a one time career dosage.


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.

You need better physics, like those off-world conditional laws of
physics that supposedly got our rad-hard DNA safely walking on the
moon, although it's always fun to otherwise pretend.


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

It actually solves most all the problems for those incest mutated
clones of Dr. Zubrin, as it'll be a less spendy one-way ticket to
ride. At least we'll once and for all be getting rid of such village
idiots.
- Brad Guth

On Jan 17, 12:08 am, jacob navia wrote:

Anyway, WHY do we need to go in person?

I agree. In person is just asking for trouble, as well as freaking
spendy as all get out.


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

Stop knocking Venus. At least there's less solar and cosmic radiation
while on that toasty geothermal surface than right here on Earth, and
there's unlimited local energy as is to work with.


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/informatiquehttp://www.cs.virginia.edu/~lcc-win32

I agree that space expeditions are extensively for robots at not 0.1%
the cost of us frail humans doing those missions, although Venus
should become doable as long as we bring along our technology and a
few of those nifty Ove Gloves.
- Brad Guth

On Jan 17, 6:53 am, Arthur Hansen wrote:
On Jan 16, 11:44 pm, Quadibloc wrote:

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.)

This is not considering that the ISS is within the Earth's Van Allen
belt. My understanding is that travelling through that and being
outside of the Van Allen belt changed the whole solar radiation
picture.

Arthur Hansen

In a very bad kind of way, especially if going anywhere near our naked/
anticathode moon as much like getting a surround cobalt gamma
treatment that's full body. Even our Moon's L1 (at nearly 60,000 km
away from the moon) isn't exactly human DNA friendly.
- Brad Guth

"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.

What astronaut has died due to exposure to microgravity? The Soviet/Russian
space stations, including Mir, had several very long duration flights for
some of their cosmonauts and none of them died.

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.

We don't know this for sure. In particular, we don't know what level of
gravity is needed. It could be that 0.5 G's of artificial gravity could be
sufficient to stop most or all of the effects of microgravity on the human
body. Unfortunately, it looks like the CAM module isn't going to be added
to ISS, so it's unclear when scientists will be able to gather data on
mammals exposed to artificial gravity between 0 and 1 G.

At any rate, providing a rotating spacecraft to provide artificial gravity
isn't a technology we lack. Its an engineering problem to solve, but it's
not as hard as you make it seem.

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.

No, it just means you need multiply redundant systems and spare parts for
those systems. It means you can't launch spare parts from earth (like Mir
and ISS), you have to carry them with you. This is simply an engineering
problem to solve, not a scientific research problem.

And THAT is the real show stopper. That technology doesn't exist today.

We've had the technology since the late 60's/early 70's. What we lack is
the level of funding necessary to make it happen.

Anyway, WHY do we need to go in person?

Because people on the spot can do far more science than robotic rovers that
move a few meters each day. Because a man on the spot just isn't the same
as a remote controlled robot. It's the same reason we have a *manned*
research base at the south pole.

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.

Lack of technology is not the problem.

Jeff
--
A clever person solves a problem.
A wise person avoids it. -- Einstein

On Jan 17, 1:08*am, jacob navia wrote:

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.

Not true. The Earth exists.

So, using lunar materials, we just build a very large radiation shield
around a large rotating cylinder... with a surface area of several
acres, and a mix of plants and animals. Lakes would cover about 3/4 of
the surface area. That should support one or two astronauts.

The required optical system for getting sunlight in while one is
radiation-shielded from all angles is described on my web site at:

http://www.quadibloc.com/science/spaint.htm

Of course, launching such a large and heavy object, constructed in
lunar orbit, on a trip to Mars would be energy-intensive, but one
could just use giant solar mirrors to boil reaction mass. So even in
the *worst-case scenario* where conventional spaceflight technology is
wholly inadequate to get humans to Mars, it *can* be done.

A flying bedstead with lots of little rockets would allow the
astronauts to land on the Martian surface.

To eliminate confusion: this is not being proposed as the only, right,
or best way to go to Mars - it is proposed as a way that would work
even if all the objections of people who say the conventional way
doesn't work were valid. If we want to go to Mars, we *can* go to Mars
- that's a fact, not a theory.

John Savard