Space travel by humans is not possible now

On Jan 30, 4:28 pm, "Jeff Findley"
wrote:
"Eric Chomko" wrote in message

...

I am not saying no to nuke power, but wouldn't it be better to have a
system that is safer? In the case of nuke power it is not a matter of
if, but more of when.

The state of the art in nuclear power (electricity) *is* safer.

No one builds reactors like Chernobyl anymore. Likewise, surely there has
been a lot done in the area of safety since Three Mile Island was designed
and built. That said, it's hard to give accurate predictions like "MTBF"
since the number of operating reactors is statistically few and the designs
are rather varied, so you can't say one specific type of failure would
necessarily apply to all designs.

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

You have any knowledge about pepple bed ractors?

Einar

"Einar" wrote in message
...

You have any knowledge about pepple bed ractors?

Not really. I'm not an expert in the field, but I have talked to people who
work on building these things and they sound pretty confident that they've
learned a lot from past reactors and that newer reactor designs are much
safer. Chernyobal was an especially bad design run in an especially bad
manner at the time of the accident. We also learned a lot from Three Mile
Island. Today's computerized monitoring equipment is much better than what
Three Mile Island had.

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

On Jan 30, 4:28*pm, "Jeff Findley"
wrote:
"Eric Chomko" wrote in message

...

I am not saying no to nuke power, but wouldn't it be better to have a
system that is safer? In the case of nuke power it is not a matter of
if, but more of when.

The state of the art in nuclear power (electricity) *is* safer.

No one builds reactors like Chernobyl anymore. *Likewise, surely there has
been a lot done in the area of safety since Three Mile Island was designed
and built. *That said, it's hard to give accurate predictions like "MTBF"
since the number of operating reactors is statistically few and the designs
are rather varied, so you can't say one specific type of failure would
necessarily apply to all designs.

With the rising cost of fossil fuels and the fact that wind and solar
power can't fill the niche, nuclear energy is bound to gain in
popularity despite the risks.

Ian Parker wrote:
:
:There is only one route to $50. The market driven route.
:

I find it funny that you say this and then argue completely against
any such approach.

:
:$100 is the market price.
:

And now back down to $88 and falling. I think everyone who knew
anything knew that $100 barrel prices were unsustainable in anything
more than the short term.

:
:This is based on Asian consumption.
:

Nonsense! Can you seriously believe that Asian demand has gone up so
much in the past year that it's driven prices up by 67% (the
difference between the price at the beginning of 2007 and the $100
peak)?

And now, after making the sensible statement above that oil prices are
market driven and the only sensible way to lower them must also be
market drive, you drive right over the cliff and contradict yourself.

:
:$50 - You need
:
:1) Nuclear power (peaceful)
:

Why? How does this impact oil consumption or prices? You are aware
that oil only accounts for something like 3% of total US electrical
production, right?

:
:2) More efficient energy use.
:

Conservation isn't a market-driven approach to REDUCING prices and
never will be, since if the market thought conservation was the answer
at a lower price it would have occurred on the way up.

:
:3) Most important solar power and a hydrogen economy. Progress has
:already been made. The latest cells will recover their cost in a sunny
:environment in a year or so.
:
:Hydrogen can be used on its own or to produce oil from coal.
:

And yet nobody in the market is jumping on either of these, even when
oil prices were temporarily artificially high. This should tell you
that they are NOT economically viable at these price levels.

Solar power is FIXED power. Most petroleum is not used for fixed
power (3% of fixed power is from oil, remember?).

Cars are not set up to use hydrogen, nor is the distribution system.
The conversion costs are very high which means that fuel prices need
to stay VERY high for a long time before this will occur driven by the
market.

:
:There is a cloud on the horizon if we have large numbers of fuel cell
:driven vehicles and that is the shortage of platinoids for catalysts.
:Its OK for celebraties to drive "green" cars which might not be quite
:so green if everyone were driving them.
:

This is the same concern that was raised when we started putting
catalytic converters on cars. It hasn't really been a problem.

:
:We need a rational global space policy. We need a rational global
:energy policy. The two are or course linked. I feel certain
:individuals are in a state of denial about both.This is hampering
:discussion.
:

So you jump from your opening where you say it must be market-driven
to your ending where you say it essentially requires a command economy
("rational global energy policy").

Just what is it about "market-driven" that you don't quite understand,
Ian? No 'planning' or 'command' is required if you let the market
drive, since the market will do what it does based on demand and
prices.


--
"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

Of robust and rad-hard types of micro-robotics in space isn't where
the big payoff is, as that's doable as is and getting per kg cheaper
by the day.
.. -Brad Guth


jacob navia wrote:
Human space travel is a big source of profits for aerospace companies.

The advantages are that the scientific returns are very low or zero, so
there is no need to spend money paying scientists to gather and
understand data, all the profits go in building hardware that is
used for a few days/weeks and the thrown away.

In the ISS, for instance, billions have been paid to aerospace
industries for hardware that has produced not a single intersting
scientific result, and that has dwarfed the budget of science within
NASA.

Take for instance a mission like the Mars Rovers. After four years in
Mars, those machines are still working perfectly, returning scientific
data and allowing the exploration of Mars in an unprecedented scale.

The total budget of the Mars rovers was around 900 million, and it has
returned gigabytes of data, measurements, photographs, etc.

This is more or less what a single trip of the space shuttle costs.

In this group, one of the most vocal advocates of this "humans
into space and to hell with science" is Mr McCall, that will not
hesitate to insult anyone disagreeing with his views.

Mostly his arguments are just at the level of

"bull ****"

or

"stupid".

Personally I do not care, but facts are stubborn. Human presence
in space is unnecessary, even more so in the moon. The basic
groundwork is not there, in terms of working life support
systems that can stay in space for 4 years without any failure.

It can be argued that astronauts can "fix" a life support system,
and this is partially true, but it depends heavily on the type
of failu to repair a life support system you need a life support
system that keeps you alive.

There is an emergency escape frm the ISS. That choice is not available
halfway from the distance to Mars.

This is a basic UNSOLVED problem.

Space radiation is another, completely unsolved one. The experience
of the ISS is of no use since the earth magnetic field protects the
ISS, a protection that people in the way to Mars will not have.

This is another UNSOLVED problem.

Gravity effects (or rather its absence) is another problem. We just
do not know since we have no data about the long term effects on
the body of 2 years without gravity. It is a fact that exercise
and countermeasures do NOT work, and there is a continuous bone
mass loss in space.

This is another UNSOLVED problem.

You can say that "artificial gravity" etc, but the problems to solve to
put that to work are quite big.

Another unsolved problem is how to land in Mars, what is a very
difficult problem that is very complex to solve for small
mass vehicles and completely unknown for huge mass vehicles
like a spaceship with 4 people and its life support, supposing the
2-3 years supplies are previously sent to Mars by robots.

This host of problems (all of them unsolved) makes any proposition for
manned Mars missions just a waste of money.

All of this problems CAN be solved, and (I am sure) they WILL be solved,
but not before this century has finished.

A new society is needed to give the drive to go into space. A society
that cares about exploration and that is ready to pay make the effort
it will take to develop a life-support system that can take us to the
stars.

Before that life support system is there, all the things being
done here are just pipe dreams.

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