One of the things seldom brought up here is how truly incompatible man is with space. And space life sciences is a stagnant science which gets only new LEO datasets to study.

Without depressing folks here, unless manned exploration beyond LEO is commenced very soon, the data necessary to allow man to survive in space outside of LEO will be forgotten and lost. Here we have many pro-space people but it's not enough to be pro-space, one has to know exactly what is needed to keep man alive and what science is needed to continue with the plethora of problems we already observed.

Man is keyed to the Earth. It is fair to say man is a part of the Earth. When we are removed from the Earth we suffer. I suspect many here have no idea of how much degeneration and deterioration occur when man leaves Earth & LEO.

Explosive decompression or acute hypoxia is the stereotype dilemma of the spacecraft or spacesuit, but that is the very least of the worries. Acceleration and various degrees of weightlessness changes the blood and changes in gravity even change the formation of urine resulting in urinary claculus formation.

Whenever someone proposes manned outposts or planetary exploration craft that do not have artificial gravity mechanisms, I shake my head because its like cursing the astronauts to death and disease. And when I see folks promote cheap craft I know these same folks don't keep a mental list of all the hazards. The solar wind and solar flares are enough of a hazard to create a constantly available shielded area and these radiation are a fairly well known hazard, but galactic radiation is even more deadly.

Galactic radiation is high-energy nuclei - roughly 86% protons, 15% alpha particles and the remainder of high atomic number elements. These particles pierce the retina, the brain and the hypothalamus and lesser organs. I recall reading one paper that predicted folks exposed would have their life expectancy cut down by 20-30% and maybe much more.

Just to make it more real for you, these particles leave a trail of ionization in their wake. Like being stabbed by tiny needles that penetrate right through you, yet the needles would actually damage you less than these particles do. The needles would have to be 1000 degrees or so and burn your tissue to do even partially as much damage as galactic radiation does. Ionization radiation damage is permanent. While not nearly as dense as the solar wind, the total lack of data on the density of these particles paths through our solar system makes even plotting a course to Mars a proposition that could kill the crew "invisibly" long before they arrive.

And around Earth we have mapped our radiation belts - but any explorers will have to map any planets they approach. Just randomly entering orbit around a planet could be deadly. High energy particles we avoid and minimize exposure to during launch, re-entry and orbiting might appear like nothing next to another worlds bands of radiation. Conceivably one wrong move in a space craft not shielded could mean death in a matter of minutes for the crew. And even a non-fatal dose could mean a life of roentgen ulceration.

And even all this is just a tiny fraction of the physiological stresses and dangers that man must endure when he leaves the Earth.

So let's not diminish the risks in our advocacy of space exploration. Any manned space enthusiast should try and become well versed in the limited data we have already acquired and advocate science experiments and missions that can advance key areas that are known to be serious, serious restrictions to manned space exploration.

Even here on Earth folks who don't avoid the sun are accumulating non-dispersing ionizing radiation. So don't play too much golf, swim during the day or even contemplate tanning. All these things will destroy your looks, your health and shorten your lifespan.