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I think it might be insightful to read this report, I'm not sure that it was criminal negligence, I think it was more a problem with the culture at NASA at the time and specifically management's seeming loss of perspective with regards physical realities and lack of basic statistical and risk analysis.
http://science.ksc.nasa.gov/sh... Appendix F - Personal observations on the reliability of the Shuttle
by R. P. Feynman

Introduction

It appears that there are enormous differences of opinion as to the probability of a failure with loss of vehicle and of human life. The estimates range from roughly 1 in 100 to 1 in 100,000. The higher figures come from the working engineers, and the very low figures from management. What are the causes and consequences of this lack of agreement? Since 1 part in 100,000 would imply that one could put a Shuttle up each day for 300 years expecting to lose only one, we could properly ask "What is the cause of management's fantastic faith in the machinery?"

The remainder of the report is quite revealing.

At least one engineer recommended against the launch for precisely that reason. He was overruled. I guess the military uses for that TDRS payload were more important than safety....

"Actually it is well known from the recovered tapes and the recorded talks of the crew of Columbia, that all survived the accident until the crew cabin crash landed."

The Executive Summary of the Columbia Crew Investigation Survival Report page XIX says otherwise.

http://www.nasa.gov/pdf/298870...

Eh? No, the crew of Columbia did not survive all the way down. Perhaps you are thinking of challenger, where there is some debate on if they survived until impact. In the case of Columbia the crew was dead four times over before impact. The lethal factors NASA identified were:

1. Depressurization of the crew module at or shortly after orbiter breakup.
So, we start with denying the crew oxygen. None closed their helmets when pressure dropped to 0 in a fraction of a second at the start of the breakup.
2. Exposure of unconscious or deceased crew members to a dynamic rotating load environment with a lack of upper body restraint and non-conformal helmets.
Then we bang them around a bit in what can be best described as a rolling garbage compressor full of sharp and heavy things, in helmets not designed to protect against this kind of force and without proper seat belts.
3. Separation of the crew from the crew module and the seat with associated forces, material interactions, and thermal consequences.
Then we break the box apart, exposing the crew to an unprotected reentry into atmosphere
4. Exposure to near vacuum, aerodynamic accelerations, and cold temperatures.
Finally we let them free-fall back to earth...

The Columbia Crew Survival Investigation Report is a 400 page long and very dark document, but the executive summary is just a couple pages. You can find it here:
http://history.nasa.gov/columb... The bodies of the astronauts were mangled beyond recognition, which is hinted in the report, but out of respect of the astronauts details of the injuries are redacted from the report.

Oh, and don't forget to use a five year running average as in here. You can see the global five year running average temperature in 1990 was 0.3 C above the baseline; in 2000 it was about 0.8. You can also see the five year average oscillates above and below the underlying rising trend. If you use a piece of paper to cut off the graph at 1950, it looks like global temperatures are falling. In fact in the 50s global cooling was the scientific consensus, but that's coincidentally where the first contrarian papers proposing AGW were published.

I agree with Karmashock.

Look at the profile for apollo 11.

http://history.nasa.gov/SP-402....

stage 1 sthutoff is about 36 nm altitude 51 nm down range. While that may seem fast I think it is only at a 35deg angle to verticle at the time.
it weighed 3,000,000kg and the first stage was 2,300,000kg of that (total weight)

Where is your evidence that volcanic activity plays a major role ? And which active volcano is actually capable of spewing rocks and lava anywhere near Greenland ?

The Icelandic volcanoes are in a good position to cause this sort of thing. For example, a series of eruptions in mid 2010 covered a significant portion of Greenland in ash. Coincidentally (or not), "record melting" of Greenland's ice sheet was observed at the end of 2010 with the greatest "melt day anomalies" (as described in the link) observed in southern Greenland which was also the most affected by the volcanic ash released by the eruptions.

The current melting in Greenland follows a even larger eruption (up to perhaps double the size of the 2010 eruptions) this year (which is still ongoing more than two months later). There isn't as much ash generated from what I read, but you don't really need a lot of ash to change albedo of snow.

More than 95% of stuff in orbit now is junk and huge resources at NASA and DoD are used just to track it More than 500,000 pieces of debris, or “space junk,” are tracked as they orbit the Earth. They all travel at speeds up to 17,500 mph, fast enough for a relatively small piece of orbital debris to damage a satellite or a spacecraft. http://motherboard.vice.com/re... http://www.nasa.gov/mission_pa...

it will be much harder to remove later. By the time we are building moon telescopes and research bases, we will be using half the payload for tools to sweep the junk up http://science.nasa.gov/scienc...

More than 95% of stuff in orbit now is junk and huge resources at NASA and DoD are used just to track it More than 500,000 pieces of debris, or “space junk,” are tracked as they orbit the Earth. They all travel at speeds up to 17,500 mph, fast enough for a relatively small piece of orbital debris to damage a satellite or a spacecraft. http://motherboard.vice.com/re... http://www.nasa.gov/mission_pa...

it will be much harder to remove later. By the time we are building moon telescopes and research bases, we will be using half the payload for tools to sweep the junk up http://science.nasa.gov/scienc...

cf. http://amyshirateitel.com/2011...

If the problem was only economical, there wouldn't be a problem nowadays for a new launch vehicle to go to Mars. The $6 billions NASA budget in 1966 would be equivalent to $43 billions today. Even at FY 2013 budget, $17 billions, assuming the R&D had already been done, documented, and tooling still exist, the saturn launch vehicle could easily be re-made. But strangely, it could not. you are also disproved by the fact the NASA engineer have only been testing the Rocketdyne F-1 engine quite... recently... http://www.nasa.gov/exploratio...

Let's face it, the US space program is not what it used to be, but hey, if you like to live in the past, good for you :-/

.
Dark Matter Core Defies Explanation
http://www.nasa.gov/mission_pa...

Of course I admit I am a little biased in my analysis above, because my own theory actually predicts this lensing effect and doesn't even require any new fictitious or magic particles to do it. When the Abell 520 survey came out it merely confirmed my hypothesis of how the physics actually works at the quantum level.

Actually these are not planets according to the new classification.

First, it must orbit the Sun.
Second, it must be big enough for gravity to squash it into a round ball.
And third, it must have cleared other objects out of the way in its orbital neighborhood.

http://missionscience.nasa.gov...

Yep. I believe that this stuff is what astronomers call "dust".

Actually these are not planets according to the new classification.

First, it must orbit the Sun.
Second, it must be big enough for gravity to squash it into a round ball.
And third, it must have cleared other objects out of the way in its orbital neighborhood.

http://missionscience.nasa.gov...

You're pretty behind the times. Much if not most of the code is available now. The NASA/GISS Model E, one of the main Global Climate Models is available here. The data and code for Michael Mann's original hockey stick graph are available here.

For a comment on the code in your original code see here.

The 1937-1937 were FAR hotter than today, across almost the whole United States. (I'm not claiming it was global.) While that might not be "global climate change" it puts any of today's "extreme weather events" to shame.

Nope, hotter now.

Eratosthenes pre-dated Columbus by some time...he was not wildly wrong about the circumference of the Earth, but the size of the Atlantic Ocean.

Columbus was wrong about both. Despite having the correct size of the Earth computed very closely by Eratosthenes (we do not know how closely though since the exact size of this "stadia" is unknown), Columbus still accepted a grossly incorrect figure due to his own (flawed) interpretations of ancient geographers.

Looking at the map, it seems like the direction to look from Connecticut will be south/southeast (but mostly south). It first has to rise above the Earth's curvature far enough to be visible from CT, and by that time it's already quite far out to sea to the east. Looks like a similar situation in NJ - it's not going to appear to the southwest.

http://www.nasa.gov/press/2014...

Of course NASA is used to doing this.

The ocean below 1.24 miles hasn't warmed. The ocean above that has, and it turns out it has warmed more than originally thought: Link.

http://www.theregister.co.uk/2...
Doubled CO2 means under 2 degrees warming

"8th December 2010 13:24 GMT - A group of top NASA and NOAA scientists say that current climate models predicting global warming are far too gloomy, and have failed to properly account for an important cooling factor which will come into play as CO2 levels rise."

Yes, because a news site without links to the actual published research or subsequent scientific discussion is to be taken at face value. However, it didn't take much Googling to find that the so-called study being referenced in the link was authored by none other than Judith Curry, a well-known climate crank. Her work has been scientifically eviscerated many times over. In other words, she has no credibility.

The latest research, done by several different scientists at several different institutions over the past couple years seem to be averaging around 4C. The AR5 centered around 3C.

http://www.nasa.gov/topics/ear...
""Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time," says Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data. "

Why would a 150 year melt cycle be "right on time" in warming world? Never mind somebody made the headline "Unprecedented melting of Greenland ice".

How can a cyclical even be unprecedented?

Again, you are mixing journalistic sensationalism with actual science. That being said, irregardless of the event, Greenland is experiencing rapid mass loss. There have been multiple papers on the subject.

I believe Mr. Hansen left shortly after this. I could be wrong but I think it was around that time.

This had nothing to do with why he left NASA. HE RETIRED. He mentioned his retirement several years before he actually left. He worked there for 46 years. Now he's following his passion as the director of the Program on Climate Science, Awareness and Solutions at Columbia University's Earth Institute.

http://www.nasa.gov/press/2014...

Of course NASA is used to doing this.

The ocean below 1.24 miles hasn't warmed. The ocean above that has, and it turns out it has warmed more than originally thought: Link.

http://www.theregister.co.uk/2...
Doubled CO2 means under 2 degrees warming

"8th December 2010 13:24 GMT - A group of top NASA and NOAA scientists say that current climate models predicting global warming are far too gloomy, and have failed to properly account for an important cooling factor which will come into play as CO2 levels rise."

Yes, because a news site without links to the actual published research or subsequent scientific discussion is to be taken at face value. However, it didn't take much Googling to find that the so-called study being referenced in the link was authored by none other than Judith Curry, a well-known climate crank. Her work has been scientifically eviscerated many times over. In other words, she has no credibility.

The latest research, done by several different scientists at several different institutions over the past couple years seem to be averaging around 4C. The AR5 centered around 3C.

http://www.nasa.gov/topics/ear...
""Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time," says Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data. "

Why would a 150 year melt cycle be "right on time" in warming world? Never mind somebody made the headline "Unprecedented melting of Greenland ice".

How can a cyclical even be unprecedented?

Again, you are mixing journalistic sensationalism with actual science. That being said, irregardless of the event, Greenland is experiencing rapid mass loss. There have been multiple papers on the subject.

I believe Mr. Hansen left shortly after this. I could be wrong but I think it was around that time.

This had nothing to do with why he left NASA. HE RETIRED. He mentioned his retirement several years before he actually left. He worked there for 46 years. Now he's following his passion as the director of the Program on Climate Science, Awareness and Solutions at Columbia University's Earth Institute.

http://www.nasa.gov/press/2014...

Of course NASA is used to doing this.

http://www.theregister.co.uk/2...
Doubled CO2 means under 2 degrees warming

"8th December 2010 13:24 GMT - A group of top NASA and NOAA scientists say that current climate models predicting global warming are far too gloomy, and have failed to properly account for an important cooling factor which will come into play as CO2 levels rise."

http://www.nasa.gov/topics/ear...
""Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time," says Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data. "

Why would a 150 year melt cycle be "right on time" in warming world? Never mind somebody made the headline "Unprecedented melting of Greenland ice".

How can a cyclical even be unprecedented?

I believe Mr. Hansen left shortly after this. I could be wrong but I think it was around that time.

http://www.nasa.gov/press/2014...

Of course NASA is used to doing this.

http://www.theregister.co.uk/2...
Doubled CO2 means under 2 degrees warming

"8th December 2010 13:24 GMT - A group of top NASA and NOAA scientists say that current climate models predicting global warming are far too gloomy, and have failed to properly account for an important cooling factor which will come into play as CO2 levels rise."

http://www.nasa.gov/topics/ear...
""Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time," says Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data. "

Why would a 150 year melt cycle be "right on time" in warming world? Never mind somebody made the headline "Unprecedented melting of Greenland ice".

How can a cyclical even be unprecedented?

I believe Mr. Hansen left shortly after this. I could be wrong but I think it was around that time.

No http://www.skepticalscience.co...

Sorry but that article claims the heat is going into the ocean. However, NASA says NO it's not. http://science.nasa.gov/scienc... Again real science trumps.

Perhaps you could use your obviously epic google skills to look up the Western Antarctic Ice Sheet. You know the one the article is actually talking about? The one that is shrinking and unstable and could cause sea levels to rise by 1.2 metres? I think that's worth at least keeping an eye on. Don't you?

Enters Robonaut.

while that was an absolutely stupid thing to do, its not really relevant to the topic at hand here now is it??

It's not even really true; it's just bamboozlement for people who want to be bamboozled. If you listen to the actual fracking interview, he says that his goals, on this particular trip to the Middle East include outreach to the Muslim world, including reminding them in their role in the development of science. That is a non-surprising goal for an official trip to a particular region. I have a news flash - at the recent IAC meeting, he congratulated the Indians on the initial success of their MOM Mars mission. I suppose the Telegraph will take offense of that too.

I have met Mr. Bolden several times, and had the opportunity to see him in action. He is an excellent NASA administrator who is seriously focused on "boots on Mars," not self-esteem initiatives.

Why? It is Darwin time. Let the fittest survive and the first to die to get a unit in her name, according to the old custom.

Here is a map of intelligent civilizations who have successfully reproduced (by experiment in the laboratory) the conditions for creating Gamma Ray Bursts. No one knows whether this map is up to date or even functional because it requires the installation of Microsoft Silverlight, which is only used by Netflix users who would rather watch movies than ping the dying remnants of failed civilizations. Our knowledge of Gamma Ray Bursts is incomplete because astrophysicists have devoted far more time to avoiding Silverlight, which they consider to be a greater danger to life here on Earth.

Here is the list of successful lab experiments observed to date. Due to obvious Y2K errors in the naming convention of GRBs attempts to collate this data over the centuries have been unsuccessful, leading to time paradoxes and fistfights.

The light curves of GRB events ech contain a complex pulse-coded message placed there by the Grand Architect that says in effect, "Whatever you do... don't do this." While the signals have not been decoded, their diversity suggests that there are a number of things that one just should not do. Except for plot on the bottom right which cannot be right, I did that in High School.

Because the characteristics of celestial GRBs mimic the explosion of fission bombs, these bursts are Nature's Way to push paranoid little civilizations over the edge to go full-out on one another during nuclear adolescence. There is a reality show out there that showcases one of these every week with a laugh track dropped in at every retaliatory response, rousing applause at the end.

Let me check, maybe it's on Netflix...

As this study shows, the missing heat recently found in the deep ocean between 700m and 2000m is required to account for observed sea level rise. So not only does the increased warming in the deep ocean close the radiative imbalance budget, it also closes the sea level rise budget. So yes, the law of conservation of energy is not challenged by this new finding.

Huh? Are you reading the same page I am? According to the page linked to by OP, the deep ocean HASN'T warmed. Quote:

From the total amount of sea level rise, they subtracted the amount of rise from the expansion in the upper ocean, and the amount of rise that came from added meltwater. The remainder represented the amount of sea level rise caused by warming in the deep ocean.

The remainder was essentially zero. Deep ocean warming contributed virtually nothing to sea level rise during this period.

The direct implication -- in fact their conclusion -- was that there WAS NO warming in the deep ocean at all.

Beamed-energy Propulsion

Lasers and microwaves are among the beamed-energy propulsion concepts the Advanced Space Transportation Program is pursuing. If the energy to propel a spacecraft doesn’t have to be carried on board the vehicle, significant weight reductions and performance improvements can be achieved. Beamed-energy propulsion uses a remote energy source — such as the Sun, a ground- or space-based laser or a microwave transmitter — to send power to the vehicle via a "beam" of electromagnetic radiation. Presently, beamed energy is the most promising technology to lower the cost of space transportation to tens of dollars per pound. Research into this technology is a joint effort of the Marshall Center, the Air Force Research Laboratory Propulsion Directorate at Edwards Air Force Base, Calif., and Rensselaer Polytechnic Institute of Troy, N.Y.

Earth-to-orbit for $30 to $100 a pound? Space tourism becomes a reality. Asteroid mining is next. Permanent outposts on the moon, with low-g "fall-safe" health care for the elderly. Space-based power generation. This will open up the whole solar system.

Antarctic ice recently set a historic record. And not just sea ice, either. Satellite data has been showing the land volume to be growing too.

Are you sure about that? People usually say the sea ice is increasing in extent, but that the land ice (the bit that might raise sea levels) is shrinking rapidly. For example:

http://climate.nasa.gov/news/242/

Gravity data collected from space using NASA's Grace satellite show that Antarctica has been losing more than a hundred cubic kilometers (24 cubic miles) of ice each year since 2002. The latest data reveals that Antarctica is losing ice at an accelerating rate, too.

/. had a recent story on this too, based on data from the same satellite:

http://news-beta.slashdot.org/story/14/09/30/2351213/antarctic-ice-loss-big-enough-to-cause-measurable-shift-in-earths-gravity

Turns out "may have"... and "suggests" turns out to be "is not" ... "there"...

http://www.jpl.nasa.gov/news/n...

JPL just compared deep ocean temps with what they were in 2005 and found there is no warming. So the deep oceans are not warming.

This means the "missing heat" issue remains a problem for the people working on these climate models. And this "may have" ... "suggests" that maybe the reason the heat is missing is because there isn't actually any warming. Think I'm wrong? Where it is the heat?

Whatever it is, it's not very relevant in the global warming discussion, because climate != weather.

Actually, it's quite relevant, for climate is simply the integral of weather of a pre-determined amount of time. NASA lays this out quite nicely. Note as a result of selecting a different time basis for the integration, one can have significant - or no - change in climate.

Climate IS, in fact, weather - just over a longer scale

.

No heating in deep oceans since 2005

Not sure what you mean by few references...All these were on that page.

http://www.grida.no/publicatio...
http://dx.doi.org/10.1038/ncli...
http://www.weatherzone.com.au/...
http://pubs.giss.nasa.gov/docs...
http://www.sciencemag.org/cgi/...
http://www.copenhagendiagnosis...
http://www.iac.ethz.ch/people/...
http://www.aip.org/history/cli...
http://www.aip.org/history/cli...
http://www.giss.nasa.gov/resea...
http://www.realclimate.org/ind...
http://www.realclimate.org/ind...
http://web.archive.org/web/201...

As for Dyson...two imporat words you dont find in his biography are "climate scientist".
In fact, he rather quite well falls into the science trope of the phsycist who insits on talking about things outside his realm of expertise.
(There's even an XKCD for that, though I am missing the link atm)

Not sure what you mean by few references...All these were on that page.

http://www.grida.no/publicatio...
http://dx.doi.org/10.1038/ncli...
http://www.weatherzone.com.au/...
http://pubs.giss.nasa.gov/docs...
http://www.sciencemag.org/cgi/...
http://www.copenhagendiagnosis...
http://www.iac.ethz.ch/people/...
http://www.aip.org/history/cli...
http://www.aip.org/history/cli...
http://www.giss.nasa.gov/resea...
http://www.realclimate.org/ind...
http://www.realclimate.org/ind...
http://web.archive.org/web/201...

As for Dyson...two imporat words you dont find in his biography are "climate scientist".
In fact, he rather quite well falls into the science trope of the phsycist who insits on talking about things outside his realm of expertise.
(There's even an XKCD for that, though I am missing the link atm)

What do you mean by that? What are "people like me"? "Laymen"?

Obviously...

Why are you making assumptions about who I am? If you clicked on my homepage, it would only take a few seconds to realize that you're wrong. But more importantly, it's not necessary or productive to accuse someone of being a layman. There's no reason to be nasty. Just discuss the science, and leave your assumptions about who the other person is out of it.

I linked you the 'half value layer' articles ... metric tons per square meter are irrelevant.

No. Metric tons per square meter = thickness * density, so if density is relevant then metric tons per square meter is also relevant.

Relevant is how dense the material is and what its actual properties are to 'break' or capture cosmic rays. A ton of water simply does not equal a ton of lead, even if you believe so after you got missleaded by that NASA article :)

The NASA article I showed you explicitly calculated the required shielding using silicon dioxide (Moon dust) as I've failed to explain. They're not saying a ton of water exactly equals a ton of lead, and neither am I.

no one uses tons per m^2 to describe radiation absobtion. A measure like that would imply the material used is irrelevant, which it is not. The correct material is the prime shielding factor.

No, density is the prime shielding factor. That means metric tons per square meter is a good first order approximation.

That is a laymen explanation for people like you. I linked you the 'half value layer' articles ... metric tons per square meter are irrelevant. Relevant is how dense the material is and what its actual properties are to 'break' or capture cosmic rays. A ton of water simply does not equal a ton of lead, even if you believe so after you got missleaded by that NASA article :)

Again, metric tons per square meter = thickness * density. That means the half-value layer should be inversely proportional to the shield's density. So if metric tons per square meter are relevant to the half-value layer, the half-value layer should be inversely proportional to the shield's density.

Did you try plotting those half-value layers against the inverse densities for concrete, steel, lead, tungsten and uranium? If you did, you'd notice that they're all close to a straight line. So metric tons of shielding per square meter is a good first order approximation.

Also, you claimed I mixed up the travel time, but you still haven't shown that my 3.5 day travel time to Mars at 0.25g is somehow wrong. What travel time did you get?

The question is when will you read science ?

Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends
The ups and downs of global warming

no one uses tons per m^2 to describe radiation absobtion.

Except NASA: "Passive shielding is known to work. The Earth's atmosphere supplies about 10 t/m^2 of mass shielding and is very effective. Only half this much is needed to bring the dosage level of cosmic rays down to 0.5 rem/yr. In fact when calculations are made in the context of particular geometries, it is found that because many of the incident particles pass through walls at slanting angles a thickness of shield of 4.5 t/m^2 is sufficient."

You are mixing some stuff up :) actually lots of it.
Radiation absorption is not measured in tons per m^3.

If I'm mixing lots of stuff up, just explain how this NASA study was wrong to conclude that 4.41 tons/m^2 would be sufficient shielding.

Growing up on the mythology of Apollo (the space program not the god) I was shocked to read the things found in the quite below. But mythology is one thing and history is another.

As a Senator Kennedy did not believe in manned space flight, he thought the money should be spent on social programs. He was more open to less expensive robotic missions.

As President he was still not interested in manned flight. The "new frontier" was actually of little interest to Kennedy. What did get Kennedy behind the Apollo program was, payback to Vice President Johnson for his support and more importantly Cold War politics.

Shockingly, here is NASA's portrayal of Kennedy's motivations:
"Kennedy as president had little direct interest in the U.S. space program. He was not a visionary enraptured with the romantic image of the last American frontier in space and consumed by the adventure of exploring the unknown. He was, on the other hand, a Cold Warrior with a keen sense of Realpolitik in foreign affairs, and worked hard to maintain balance of power and spheres of influence in American/Soviet relations. The Soviet Union's non-military accomplishments in space, therefore, forced Kennedy to respond and to serve notice that the U.S. was every bit as capable in the space arena as the Soviets. Of course, to prove this fact, Kennedy had to be willing to commit national resources to NASA and the civil space program. The Cold War realities of the time, therefore, served as the primary vehicle for an expansion of NASA's activities and for the definition of Project Apollo as the premier civil space effort of the nation. Even more significant, from Kennedy's perspective the Cold War necessitated the expansion of the military space program, especially the development of ICBMs and satellite reconnaissance systems."
http://history.nasa.gov/Apollo...

Another interesting and shocking bit of trivia.

"Consistently throughout the 1960s a majority of Americans did not believe Apollo was worth the cost, with the one exception to this a poll taken at the time of the Apollo 11 lunar landing in July 1969. And consistently throughout the decade 45-60 percent of Americans believed that the government was spending too much onspace, indicative of a lack of commitment to the spaceight agenda."
http://www.theatlantic.com/tec...

Yep. That's the same sanity check used by that NASA study:

"Passive shielding is known to work. The Earth's atmosphere supplies about 10 t/m^2 of mass shielding and is very effective. Only half this much is needed to bring the dosage level of cosmic rays down to 0.5 rem/yr. In fact when calculations are made in the context of particular geometries, it is found that because many of the incident particles pass through walls at slanting angles a thickness of shield of 4.5 t/m^2 is sufficient."

Water could be an effective shield, and would be especially easy to apply and repair. Just melt it and let it freeze in place. That's how most of the lighthuggers in Revelation Space were shielded, as well as the starship in Songs of Distant Earth.

The only downsides I can think of would be the low tensile strength, so a water shield couldn't spin with a rotating ship, and the fact that if the ship overheats then its radiation shield sublimates away...

Centrifuges need to rotate no faster than 1 rpm to avoid inducing motion sickness. That's for long-term colonies, so maybe 2 or 3 rpm would be acceptable for astronauts selected for their resistance to motion sickness. Maybe even faster if they're hibernating the whole way. But regardless, the centrifuge would still have to be quite large.

If the centrifuge is inside the shielding, that makes the shield enormously bigger and heavier. Alternatively, only the hibernation/living chamber at the end of the centrifuge could be shielded. But that requires that the shielding mass be attached to the centrifuge, which vastly increases its required tensile strength. That's why the NASA study placed the colony's centrifuge inside a separate shield: if the shield rotates with the centrifuge then the centrifuge would have to be built out of carbon nanotubes. If the shield is separate then the centrifuge can be built out of aluminum.

NASA found that 441 grams/cm^2 of silicon dioxide (Moon dust) would be sufficient shielding, which equals 4.41 tons/m^2. Hibernation dangers and personal preference regarding books may vary, of course.

Reliable shielding isn't impossible. Shielding of 4.41 tons/m^2 is sufficient. Putting the crew in hibernation does reduce shielding because otherwise the entire back side of the spacecraft (at least) has to be covered with 4.41 tons/m^2 of shielding. In hibernation, the crew could be closely packed and aligned with their feet towards the sun, reducing the required shielding area and mass.

"a little lower than normal" ?

You're as bad as the other cherry pickers.

http://www.nasa.gov/press/2014...

Any signs we find of it, would be a snapshot of some point in the past. We could communicate with a civilization a few light years away, though it would be very slow since it would take 12 months for a beam of informational light to reach a single light year away. With our current tech, it would take us way too long to get to any other star systems. unless we stumble onto a worm hole near Mars or something.

Actual link:

http://earthobservatory.nasa.g...

That's because of drought, not because of something stupid and short sighted.

Here's a working link, as provided by the AC here.

You aren't quite right that the satellite gravity scientists are just using climate as a "hook" to display their techniques. A major reason for the launch of these very precise gravity satellites is to use gravity to monitor the movement of water (not just ice) in and around the Earth. Hence the name of the GRACE satellite -- Gravity Recovery and Climate Experiment. The NASA GRACE fact sheet is at -- http://earthobservatory.nasa.g... with more details.

http://earthobservatory.nasa.g...

Quite startling, how the water levels change. But read the article to see why this is happening, and where it's going. It seems it doesn't take a "totalitarian government" to do stupid, short-sighted things. But hey, enjoy your golf at Vegas, hear? And the water shows.

Even getting the first ship with humans in it would be a major ordeal. At current estimates based on the time it would take to get people to Mars, it would take 1.36 million kg (article says 3 million pounds) of supplies. That's for a round trip, but we are planning to stay there, so you'd probably need most of those supplies to still be there. You'd save on fuel because you wouldn't be returning but you'd need other supplies to sustain life when you were there. Even the biggest heavy launch vehicle can only lift 50,000 kg of supplies, meaning it would take over 27 launches just to get the supplies into earth orbit.