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The culprit turned out to be the innermost core, made of a porous material which, during its manufacture, trapped many bubbles of air, at atmospheric pressure. Later vacuum-chamber experiments suggested that the unwinding of the reel uncovered pinholes in the insulation. That in itself would not have caused a major problem, because the ionosphere around the tether, under normal circumstance, was too rarefied to divert much of the current. However, the air trapped in the insulation changed that. As it bubbled out of the pinholes, the high voltage ("electric pressure") of the nearby tether, about 3500 volts, converted it into a plasma (in a way similar to the ignition of a fluorescent tube), a relatively dense one and therefore a much better conductor of electricity. The instruments aboard the tether satelite showed that this plasma diverted through the pinhole about 1 ampere, a current comparable to that of a 100-watt bulb (but at 3500 volts!), to the metal of the shuttle and from there to the ionospheric return circuit. That current was enough to melt the cable.

The board found sufficient evidence to identify two possible causes of the breach in the insulation -- foreign object damage, or a defect in the tether itself. Debris and contamination found in the deployer mechanisms and in the tether itself could have been pushed into the insulation layer while the tether was still wound on its reel. The investigation found evidence of damage to copper wire in the tether, and also established that normal forces on the tether while on the reel could push a single copper strand or foreign debris through the insulation.

But that is nowhere close to 20.

And even has HTML interfaces. Try NASA's archieplex for example. or this one. Or try another or yet another.

here is a great site for MIR. It gives it's location in orbit, etc... MIR spacestation

The energizer bunny was funny, but the real Mars weather can be found here:

Mars Today It includes current conditions. I believe this site has been up before the Internet was popular.

And current solar data for those intersted


~afniv
"Man könnte froh sein, wenn die Luft so rein wäre wie das Bier"

I thought a neutron star had the density of an atomic nucleus, but was not compressed into one nucleus. Of course, this link doesn't seem to indicate whether I'm wholely correct or not. It does support my statement on the density, but doesn't say whether or not it's compressed into one nucleus.

Of course, if it's compressed into one nucleus, it would help to explain the immense amount of x-rays this sucker is putting out.

Kierthos

1. Open source library of knowledge for developing nations (making the world's intellectual wealth available to all)
http://www.oneworld.org/globalp roj ects/humcdrom/
http://www.oneworld.org/globalprojects/& lt;/a>
http://www.oneworld .or g/globalprojects/humcdrom/copyrigh.htm
http://payson.tulane.edu:8888/
; http://www.globalprojects.org/
; http://www.humanitylibraries.net/ http://www.villageearth.org/
http://www.villageearth.org/ATLi bra ry/cdrom.htm

2. Open source knowledge management systems
http://www.bootstrap.org/
http://bootstrap.org/colloquium/ar chi ves.html
http://www.bootstrap.org/dkr/discussion /

3. Self-replicating space habitats (support trillions of humans in style without overrunning the earth)
http://members.aol.com/oscarcombs/s ett le.htm
http://members.aol.com/oscarcombs /sp acsetl.htm
http://www.permanent.com/
http://science.n as. nasa.gov/Services/Education/SpaceSettlement/
http://www.luf.org/
http://www.ssi.org/
http://www.ssi.org/alt-plan.html http://www.spacedev.com/
http://www.spacehab.com/
http://www.kurtz-fernhout.com/oscomak/

4. Pursue the "Ecocity Berkley" vision in the book by that name by Richard Register and look for related visions of sustainable development
http://www.amazon.com/exec/ob ido s/ASIN/1556430094/
http://www.co-intelligence.or g/y 2k_commtyorgs.html
http://www.fuzzylu.com/greencenter/h ome .htm
http://www.ulb.ac.be/ceese/meta/sust vl. html
http://www.rmi.org/

5. Work towards ending the drug war and pardoning hundreds of thousands of Americans imprisoned on non-violent drug charges. (I believe drug use is wrong and should be avoided, and by all means as it is now illegal, so don't do drugs! But as with alcohol and tobacco and caffeine, drug abuse should be considered a medical problem, not a legal one (except when like DUI it hurts or puts at risk others directly)).
http://www.pbs.org/wgbh/pag es/ frontline/shows/drugs/
http://www.drcnet.org/facts/

6. Teaching tolerance and compassion
http://www.splcenter.org/
http://www.splcenter.or g/t eachingtolerance/tt-index.html

7. Open source educational simulations and simulation construction toolkits (one of the most meaningful ways to use computers in the classroom).
http://www.gardenwithinsight.com/ http://riceinfo.ri ce. edu/armadillo/Simulations/simserver.html
http://www.creativeteachingsite .co m/edusims.html
http://www.workingmodel.com/
http://www.idsia.ch/~andrea/simtools.h tml

8. Preserving biodiversity (when it's gone, it's gone forever)
http://www.tnc.org/
http://www.environment.about.com/newsissues/enviro nment/library/weekly/aa091700.htm

9. Develop any specific sustainable technology in energy (e.g. solar), recycling (e.g. recycle computers), materials (e.g. plastics from starch), society (e.g. participatory democracy & social justice).
http://www.google.com/sear ch? q=sustainable+technology
http://www.edf.org/issues/Recycling.htm l
http://www.sustainable.doe.gov/

10. Make corporations more accountable to human needs
http://www.adbusters.org/inform ati on/foundation/
http://www.adbusters.org/c amp aigns/charter/death.html
Previous link vanished, try instead:
http://www.google.com/search?q=cache:www.adbuste rs.org/ campaigns/charter/death.html+corporate+death+penal ty&hl=en
http://www.cwsl.edu/news/n_corpo rat e_death.html
http://monkeyfist.com/articles/340& lt;br> http://www.chaordic.org/

11. Reform the "Intellectual property" laws and their related organizations, perhaps so that copyrights are for a couple decades and most patents are for a dozen years and only for true innovations. Ensure that any IP developed with any government money is immediately put into the public domain.
http://danny.oz.au/fre e-s oftware/advocacy/against_IP.html
(Lots of other Slashot links!)

12. If you don't want to get you hands dirty volunteering your own time, look around and find good people (not organizations, although the people may be in organizations) already doing good things. Pick people with a track record of years of fighting for the common good or who have already made a major accomplishment demonstrating commitment and just anonymously give them $100K without strings attached. Example: Marty Johnson at Isles, Inc.
http://www.isles.org/mileston.html& lt;br> Find people just starting a career of public service or a charitable venture and struggling to do good things and give them $20K and tell them you believe in their promise and cause. Expect a bunch of the money to be wasted but give it anyway and learn how to give effectively. For ideas, look at the grantees list of any foundation. Then ask those people who they know who are just starting out and trying to do a good job.
http://www.beldon.org/grants2000_07.htm l

When I was about thirteen, I got about seven books out of the library on money thinking I wanted to become a millionaire. Six told me how to get rich (start a business and run it well.) One of them asked me "why do you want to be rich?" That is the one whose name I remember and the ideas in it have changed my life. For advice on setting a direction of what to do with wealth, read the Book "The Seven Laws of Money" by Michael Phillips and Sally Raspberry, especially the chapter on how foundations fail in their mission and how grants go to people who sound good but usually can't deliver (i.e. how hard it is to give money away).
http://www.seeingmoney.com/SevenLaws.ht m
http://www.hallbusi nes ses.com/biographies_primers/1420.shtml

My wife and I are working on a few of these issues ourselves (and a few example links are to our stuff). We make money contracting and spend it to "buy" our own time for making quality software the market can't or doesn't seem to want to pay for. Even without IPO riches, any competent software developer can make $75K-100K in today's market. Graduate students can live on $20K a year, and so can many software developers (kids make it harder) if they follow the path of Voluntary Simplicity. It's a question of priorities.
http://www.life.ca/subject/simplicity .ht ml
http://www.simpleliving.net/slj/ http://www.scn.org/earth/lightly/ http://www.thegarden.net/simplicity/

Voluntary simplicity leaves a lot of funds for doing good deeds - even if they are done on your own time by using your own money to take time off and develop open source software or do other worthwhile ventures. Or take a job that doesn't pay as well but involves helping an organization that you believe in.
http://www.idealist.org/

There are awesome things happening over the next twenty to forty years. According to Moore's law, desktop computers in twenty or so years will be a million times faster than today's. Already computers can drive cars somewhat well and identify vegetable better than humans.

http://www.research.ibm.com/resources/magazine/199 9/number_3/machine399.html ;

Other breakthrough innovations are happening in technological areas like energy, materials, nanotechnology, communications, agriculture, biotechnology, and robotics. Use your wealth to think deeply about what all this means and do something to ensure human survival with style.

It is saddening to see people spend so much money on less important stuff (another night club in this case). Now if it was a night club where these issues are discussed, then maybe it makes sense.

Capitalism without charity is evil, because capitalism only meets the needs of people with money.

Here is a page with a tutorial on pulsars. You can listen to them, too!

This isn't just a "biggest explosion, gee whiz" story. As the article notes, very little is known about the interior of neutron stars, and this explosion probes deeper inside. As explained on this nifty page about neutron stars, there could even be all kinds of exotic stuff inside them, like strange-quark matter.

--

It'd serve many people well to have a little understanding of the physics of a black hole.
Here are a three of my favourites:

Virtual Trips to Black Holes and Neutron Stars Page

Jillian's Guide to Black holes

Got it. But this is exactly the problem. If you actually want to use the number for any purpose more meaningful than striking panic, you need to have both numbers, and not one. Mapping two independent variables onto one dimension has big problems, as the linked chart shows.

For example, an impact that would cause regional damage and has a 98% chance of striking is rated as a 3, while one with a 99% chance of striking is an 8.

Another example: According to the chart, an impact with global consequences and a 1:1000 probability merits a 2 on the Torini scale, but if it has a 1:999 probability, it jumps to a 6 on the scale.

Both of the above examples are where the spatial regions meet at a line. If you look at where they meet at a point, it's possible to nudge an impact between a ranking of 2 and 7 (KE: 10E5MT, P: 10E-2), or from a 3 to a 9 (KE:100MT, P: 0.99).

This is arbitrary and, as mentioned before, useless for anything other than scaremongering and puff-pieces.

Kevin Fox

Take a look at http://impact.arc.nasa.gov/torino/pr of. html. It shows a two dimensional chart with probability and likely damage.

If it will hit, but cause no damage, it's a zero. If it will completely destroy the earth, with less than 10^-8 probability, it's also a zero. Goes to 1, then 2, then 6, 7, 10 with increasing probability.

-KDP

You can see that none of the objects in the table has a period of 353 or 354 days. Perhaps an object with a longer period got slowed, or one with a shorter period got accelerated, by Earth-Moon approaches. Or Apollo 12's lost stage ended up here...

The Torino Scale, as presented in the link provided in the story, is useless. It tries to rank objects on a scale of 0 to 10 based on the damage they would inflict if an impact did occur, yet it simultaneously tries to rank based on the likelihood of collision, though these factors aren't necessarily correlated at all.

Basically, an object gets a 0 if it is extremely unlikely to hit the Earth and|or wouldn't inflict any damage if it did. An object gets an 8, 9, or 10 if it's certain to hit the Earth, and|or would inflict continental or global devistation.

The Torino scale doesn't give a way to categorize objects which are certain to strike the Earth but pose no danger, nor does it facilitate ranking objects that could prove catacalysmic, but have only a marginal likelyhood of impact.

Looks like something more suited to a bad asteriod movie than a NASA research site.

Kevin Fox

Shuttle launch costs are much much greater than 20-50 Million dollars. Try at least 300 Million dollars and probably closer to 1 Billion dollars.

NASA Baseline Space Shuttle Costs

If you follow the link you will see they calculate the launch costs by taking the budget available and working backwards. The first 8 flights consume the entire budget, so they fudge the last two at 90 Million each even though they don't fit in the budget! Note the maximum safe launch rate of 10/year is what is required for the ISS to be built. Another example of starting with the answer and working backwards. If we don't have a launch disaster we can probably count on the Russian built modules to provide one.

The Shuttle and NASA are the absolute worst things that ever happened to the US Space program.

Well, according to this, the farthest object we can see is about 1 billion light years away. Now, there are 5,865,696,000,000 miles in a light year.

So we'll say that the farthest object we can see is five sextillion, eight hundred sixty-five quintillion, six hundred ninety-six quadrillion miles away.

Now, at 56 digits, we're going to say that it can calculate to a precision of 10^-56.

10^-56 * 5865696000000000000000 = 5.865696*10^-35

So, a decimel at 10^-56 will represent a unit on this scale of 5.865696*10^-35 miles.

Now, there are 63,660 inches in a mile, so...

(5.865696*10^-35)*63660=3.7341020736*10^-30

So, a decimel at 10^-56 will represent a unit on this scale of 3.7341020736*10^-30 inches.

Now, the estimated size of a proton is 0.22 trillionth of an inch. That is twenty two hundred quadrillionths.

Size of Proton = .00000000000000022 inches

Size of Known Universe * 10^-56 = .0000000000000000000000000000037341020736

So, 56 digits of pi, as you can see,... is TOO accurate.

Here's the link to the Nasa site with the formula for computing an arbitrary hex digit of Pi.

Wow, that site is really cool. I remember going to it a long time ago, they certainly have kept it going.

Anyway, here's another great pic of 2 more galaxies collding.

And hell, I might as well borrow their html of the description:

Billions of years from now, only one of these two galaxies will remain. Until then, spiral galaxies NGC 2207 and IC 2163 will slowly pull each other apart, creating tides of matter, sheets of shocked gas, lanes of dark dust, bursts of star formation, and streams of cast-away stars. Astronomers predict that NGC 2207, the larger galaxy on the left, will eventually incorporate IC 2163, the smaller galaxy on the right. In the most recent encounter that peaked 40 million years ago, the smaller galaxy is swinging around counter-clockwise, and is now slightly behind the larger galaxy. The space between stars is so vast that when galaxies collide, the stars in them usually do not collide.

More information on this can be found here.
--
*Condense fact from the vapor of nuance*
25: ten.knilrevlis@wkcuhc

Also, geosynchronous orbit is incredibly high (don't know the exact figure, but it dwarfs 31 miles.)

Yep, it's 22,241 miles.

Galactic collisions or similar interactions are very common. Galaxies are large compared to the distances between them - e.g. Andromeda is about 750kpc away, and is on the order of 100kpc in radius (this is a bit fuzzy) so intergalactic distances are only a few times galactic sizes. In comparison, stars are tiny compared to separations, so stellar collisions are very rare indeed.

The Arp catalog of unusual galaxies contains many interacting/colliding galaxies. Two famous nearby examples are M51 and Centaurus A.

(If anyone cares, I do have a doctorate in astrophysics, although I'm not working in astronomy.)

Galactic collisions or similar interactions are very common. Galaxies are large compared to the distances between them - e.g. Andromeda is about 750kpc away, and is on the order of 100kpc in radius (this is a bit fuzzy) so intergalactic distances are only a few times galactic sizes. In comparison, stars are tiny compared to separations, so stellar collisions are very rare indeed.

The Arp catalog of unusual galaxies contains many interacting/colliding galaxies. Two famous nearby examples are M51 and Centaurus A.

(If anyone cares, I do have a doctorate in astrophysics, although I'm not working in astronomy.)

HELLÓ! Does nobody here read Astronomy Picture of the Day? It has new picture every day and a detailed description by a professonal astronomer. Put it in a bookmark NOW! And you call yourself geeks, sheesh!

For fans of these kinds of pictures, Astronomy Picture of the Day is hard to beat. They have a this same picture for today.

--

For fans of these kinds of pictures, Astronomy Picture of the Day is hard to beat. They have a this same picture for today.

--

Not quite -- due to decreasing air temperature, the speed of sound actually decreases as you go up for a while, then increases again until you hit near-vacuum.

• Sea level -- 1116 fps
• 36000 to 82000 feet -- 968 fps
• 150000 feet -- 1075 fps
• 250000 feet and up -- by a quirk of physics, 1116 fps again!

He was a competitive glider pilot, and won the national championship a few years in a row. After the last time, he showed everybody the little circular slide-rule he had developed to maximize speed and range (the McCready SpeedRing) which pretty much revolutionized the sport.

In the mid 70's, he was in debt to some friends for $50,000 -- and he heard about the Kramer Prize, $50,000 to the first person to fly a human powered aircraft through a 1-mile figure-eight course. McCready was building indoor duration models at the time (unbelieveably fragile creations of wire and film that would fly for 20 minutes on a few twists of a rubber band) and realized that that same technology could be used to make a plane that would win the prize. The result was the Gossamer Condor -- a externally-braced plane to make something as light and large-span as possible. It easily won the prize. Unfortunately, he went through about $100,000 to build it. Later, he won the next Kramer Prize for the first human-powered plane to fly the English Channel, and then build a few early solar powered planes (piloted by a very light young woman).

GM hired McCready to build a car to win a solar-car race across Australia. McCready's astonishing realization was that it was all about aerodynamics -- where other teams were trying to maximize the amount of energy they were getting from the sun, McCready was worried about going really fast. It won the race by several days!

McCready built a flying Pteradon for a Smithsonian movie. It flew, flapped its wings for power, and was successfully filmed for the IMAX film.

And then there are these flying wings. Truly astonishing machines. They currently hold the record for the highest-flying propeller-powered planes, and are just (to me) insanely beautiful. Here is a gallery of photos of Helios. This picture in particular I find just sublime. What a machine. What a guy.

Thad

He was a competitive glider pilot, and won the national championship a few years in a row. After the last time, he showed everybody the little circular slide-rule he had developed to maximize speed and range (the McCready SpeedRing) which pretty much revolutionized the sport.

In the mid 70's, he was in debt to some friends for $50,000 -- and he heard about the Kramer Prize, $50,000 to the first person to fly a human powered aircraft through a 1-mile figure-eight course. McCready was building indoor duration models at the time (unbelieveably fragile creations of wire and film that would fly for 20 minutes on a few twists of a rubber band) and realized that that same technology could be used to make a plane that would win the prize. The result was the Gossamer Condor -- a externally-braced plane to make something as light and large-span as possible. It easily won the prize. Unfortunately, he went through about $100,000 to build it. Later, he won the next Kramer Prize for the first human-powered plane to fly the English Channel, and then build a few early solar powered planes (piloted by a very light young woman).

GM hired McCready to build a car to win a solar-car race across Australia. McCready's astonishing realization was that it was all about aerodynamics -- where other teams were trying to maximize the amount of energy they were getting from the sun, McCready was worried about going really fast. It won the race by several days!

McCready built a flying Pteradon for a Smithsonian movie. It flew, flapped its wings for power, and was successfully filmed for the IMAX film.

And then there are these flying wings. Truly astonishing machines. They currently hold the record for the highest-flying propeller-powered planes, and are just (to me) insanely beautiful. Here is a gallery of photos of Helios. This picture in particular I find just sublime. What a machine. What a guy.

Thad

NASA has a page on previous involvement with AeroVironment, including descriptions of all previous solar aircraft, starting back in 1971 and up to the Helios (the one in this article) and the ERAST program in general. These things have come a long ways in thirty years.

Let's see here, the IIS has a projected lifespan to 10 to 25 years. Mir was continuously occupied for about 12 years. So, IIS could be decommissioned and deorbited two years short of setting a record for continuous habitation.

I'm afraid so -- the crew of Soyuz 11 were kil led when their craft decompressed after a valve came open after un-docking from the Salyut 1 station in 1971.
/.

I needed to grab a compiler and other useful programs, so I started hitting FTP sites. One of which was swedishchef.lerc.nasa.gov, a major SGI distribution site at the time (LERC is/was Lewis Research Center in Cleveland, Ohio). I was also looking to configure my machine to be an FTP server for our department so I did some poking around to see how to set up an FTP server (doing anything I can looking through an anonymous FTP login).

It turns out that a few weeks later the machine was compromised, and they noticed that I had downloaded basically everything on the machine a few weeks earlier, so they came to my mom's house looking for me. I was at school at the time, nearing finals. They actually cut me some slack and came back after finals were over to come back to question me. Thankfully they didn't take anything, but it did scare the sh!t out of me for a good long while.

George!

Let's try this link to one of my favorite sites, APOD:

http://antwrp.gsfc.nasa.gov/apod/ ast ropix.html

Good only on Tuesday.

It had to be redesigned and sent up with the antenna folded up so they could fit it in the space shuttle cargo bay. The reason it had to go up in the space shuttle even after Challenger was because of political interference where people wanted the shuttle to be used for some high profile missions to revive it a bit from the Challenger blowing up in 1986.

Ummmm... I think you've gotten confused, somehow. Galileo was always intended to be launched by Shuttle. The launch, originally intended for 1982, slipped gradually to May of 1986 through a combination of problems, some of which were Shuttle's own delays (remember how late the first Shuttle actually flew?); the mission was supposed to be orbited with a Shuttle-specific version of the LOX/LH Centaur transstage (the Shuttle-Centaur's funding problems caused some of the delay, too). Of course, in late January 1986 Challenger exploded, so Galileo was temporarily grounded for lack of a launch vehicle.

The only real redesign that happened was when Shuttle-Centaur was finally cancelled, as being too dangerous to launch with Shuttle (liquid oxygen/liquid hydrogen in your payload bay is apparently more dangerous than in your fuel tanks... :p ). The transstage was replaced with the much-smaller Inertial Upper Stage, so the flight plan was changed to a six-year multiple-gravity-whip trajectory through the inner solar system, instead of the orignal two-year direct flight. And during the three-year layoff waiting for Shuttle to fly again, Galileo was shipped from Cape Canaveral to JPL in California and back again, spending some time in storage in the interim. It's believed that the main antenna lost some critical lubricant during this unplanned shipping and storage, and this loss caused etching of the standoff pins and sockets, so the the antenna failed to completely unfurl.

So the mission was always intended to fly on Shuttle -- and Shuttle's problems indirectly precipitated the antenna failure. You're correct in that political interference was the reason the mission was to fly on Shuttle -- but it was NASA who interferred, because they wanted Shuttle to carry all the payloads, instead of using expendable launchers (even when they'd have been more suitable). And once designed and built, it would have been very hard to convert Galileo for a Titan IV launch (for example) -- it was built to interface with the Shuttle payload bay, not a Titan payload fairing.

Unfortunately, it was NASA's fault, pretty much entirely... even though the failure was incidental to everything else which went on. Sad, but true. (I regularly work with some of these guys, and believe me, they feel as bad about it as anyone else -- it's the upper management that's cross-threaded in that org.)

---

For the record, I don't think NASA can be completely blamed for the failed main antenna on Galileo.

Earlier this year I heard Bob Mitchell speaking about Galileo and Cassini - he's pretty much been at the top of both missions. One of the reasons that the main antenna failed to open was because it had to open in the first place, so it was a lot more complicated. (Ideally they would have built it fixed open, like Cassini is designed.)

It had to be redesigned and sent up with the antenna folded up so they could fit it in the space shuttle cargo bay. The reason it had to go up in the space shuttle was because of political interference where people wanted the shuttle to be used for some high profile missions to revive it a bit from the Challenger blowing up in 1986.

Cassini couldn't have the same problems because it was launched with the antenna open. Instead of the space shuttle, they just threw it on the back of one of these, which would have been preferable for Galileo aswell, since they can get much more effective propulsion to kick it off.

Even if the story provided you with nothing *cough* all the trolls *cough*. Atleast you can enjoy the images. That's one cool gallery. For example this one Enjoy!

Even if the story provided you with nothing *cough* all the trolls *cough*. Atleast you can enjoy the images. That's one cool gallery. For example this one Enjoy!

Some people at NASA from a generation raised on planetary sci-fi just doesn't get it. Colonizing the surface of the Moon would create a habitable area equal to Africa. Colonizing Mars would produce a habitable area with a surface area equal to Earth's land masses (not including ocean surface). Sure, do it someday for fun, but not first.

NASA should instead invest the bulk of its R&D in creating one self-replicating space habitat that could duplicate itself using only sunlight and asteroidal ore. If duplicating once per year in a hundred years such a habitat and its offspring would produce thousands of times the habitable surface of the Earth, enough to support trillions of humans and large populations of other species.

Remember: a planet is a very wasteful way to use mass. It is much more efficient to use shells to contain atmosphere. If you wan't gravity, just spin it. If you don't want gravity, live in bubbles.

NASA should take on the responsibility of educating the public about humankind's future in space, not pandering to old obsolete notions in an effort to get funding.

Related links:
http://members.aol.com/oscarcombs /sp acsetl.htm
http://members.aol.com/oscarcombs/s ett le.htm
http://www.permanent.com/
http://science.n as. nasa.gov/Services/Education/SpaceSettlement/
http://www.luf.org/

however, this image seems to indicate that there is life on Io and that they are using Lynx to surf our web :-)

Remember the Van Allen radiation belts around Earth? They're composed of energetic charged particles (protons and electrons), excited to high energies by the magnetosphere, and are held in their spiraling paths by the terrestrial magnetic field. Before they were discovered (in the late 50's, by James Van Allen), people like Werner Von Braun had planned to put manned satellites in a two-hour orbit -- about 1075 miles up. This turned out to be in the lower Van Allen belt, and the radiation hazard was far too great for safety, so manned spaceflight now is generally in orbits below 250 or 300 miles.

But it's Jupiter we're talking about, and the jovian magnetic field is much stronger than Earth's; the jovian equivalent of the Van Allen belts are millions of times more energetic than the terrestrial belts. Just to give you an idea of what this means to people, compare the exposure at Jupiter (say, in the neighborhood of Io) to that around Earth.

When the Apollo astronauts went to the moon, they had to penetrate the Van Allen belts twice, going out and coming back; in doing so, they received about 2 rem radiation dose. This isn't too much: the U.S. limits radiation workers to about 25 times this, each year, based on the cancer risk. When you talk acute doses -- say, you do a pass by Io, which is in the middle of the jovian belts -- the whole-body exposure which is 50% fatal within 30 days (when untreated) is around 250-300 rad (under these circumstances, 1 rad ~ 1 rem).

Jupiter's radiation belts are millions of times stronger than Earth's, so if an astronaut spent the same time in them (about 3 hours total on a lunar mission -- but Jupiter's much larger, and so your speed would have to be hugely greater to make the transit in that time) they'd get an exposure of millions of rem. In other words, they'd be dead almost immediately -- an exposure of mere seconds would probably be lethal.

Galileo is radiation-hardened, since it was intended to survive in this environment; however, it's been there for almost three times its design limit, and it must be getting pretty fried by now. As a matter of fact, last year when it made its first really close flyby of Io, there was concern that the radiation would corrupt the computer memory and cause it to go into safe mode, or blind the camera's CCD. When that didn't happen, everyone was relieved -- and they promptly did it again!

The radiation environment is severe enough that they actually expect the spacecraft to be physically destroyed in a few hundred million years, if they left it in Jupiter orbit.

---

The reason for the low bitrate is the fact that they are not using the main antenna, which failed to open long ago. Instead the engineers ingeniously reprogrammed the craft to use a low-gain antenna to transmit scientific data. The high-gain antenna was meant to transmit 134,400 bits per second (about one imaging frame per minute). Many software tricks had to be applied, as well as the use of better receiving equipment on earth, for the mission to continue as planned. Prior to the software upgrades, the low-gain antenna had a bitrate of only 8-16 bits per second! See http://www.jpl.nasa.gov/galileo/hg a_f act.html.

The value of data alone that the probe is obtaining is well worth the value of increasing the transmission ability.

The slow transmission speed is due to the fact that the main (high-gain) parabolic-dish antenna failed to open correctly on its way to Jupiter. According to the JPL web site, the main antenna was supposed to be capable of up to 134 Kbps.

Instead, they had to use the less powerful, omnidirectional backup antenna, which has worked admirably over the years. Go JPL.

--

Karma is meaningless...

Capt. Ron

Capt. Ron

"If America doesn't even think it's got enough money to pay reparations to those of African ascent for the harms done by slavery, why do we have enough money to go to mars?"

That's an amazing question. Rather than try to anwser it I will give you a link to review.

lovell-spac eta lk

Sadly, the previous budget cuts are partly to blame for the failures. In the past NASA used to design/build/launch missions as pairs ala Voyager, Pioneer and the all to pertinent Viking. It has been a long time since the budget allowed them the luxury of building and launching 2 of everything (albeit usually months apart etc). The twin mission sets provided for redundancy in the best possible cases: the cost is about 1.5 times the cost of building a single project, improvements in the design/build process benefit the prgoram, if one fails you still have the second not too far behind. I think the psycological value of this is better in the case of the sheeples too:One failure and one success on the same mission type makes it a bit easier to downplay the failure with all the wonderful data you get from the success.

I would like to show the the fact the Bonzo has aboslutely no clue which probes failed. Mars Global Surveyor is working perfectly and is mapping as we speak. He just got that confused with Mars Climate Suveryor. If anyone doesn't know what they are talking about, just got to nasa.gov

However, basic research, like everything else is best handled in a market environment. Individuals should be free to fund the basic research they see as the most valuable.

How many would choose to fund Fermilab? What private concern would or could find the money to support Jet Propulsion Laboratory? Don't forget, the government funded the manned lunar landing to which we should thank for our own microcomputer industry.

The list goes on and on and on. First, and foremost it includes the very infrastructure that supports Slashdot and everything else that matters to geeks. Without government funding there would be no Internet.

Pshaw! No matter what your political persuasion, naive extremism is rubbish. This includes libertarianism.

However, basic research, like everything else is best handled in a market environment. Individuals should be free to fund the basic research they see as the most valuable.

How many would choose to fund Fermilab? What private concern would or could find the money to support Jet Propulsion Laboratory? Don't forget, the government funded the manned lunar landing to which we should thank for our own microcomputer industry.

The list goes on and on and on. First, and foremost it includes the very infrastructure that supports Slashdot and everything else that matters to geeks. Without government funding there would be no Internet.

Pshaw! No matter what your political persuasion, naive extremism is rubbish. This includes libertarianism.