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In particular, I was impressed with the avionics computers and software. They have five computers to handle this. During ascent and descent, four of them are running identical software concurrently, and any two computers can vote another out of the loop, if they sense it's malfunctioning. The fifth computer runs an avionics package with identical specs but from a different vendor, in case a bug is discovered in the primary software. The captain or pilot can drop to the alternate software with a press of a button.

This is all pretty impressive stuff to me .. I'm just a Web peon who has to write and maintain Perl scripts. Never seen such an interesting exhibition of how stuff is engineered when lives are on the line.

Sitting here watching http://www.nasa.gov/ntv/ntvweb.html is the most satisfying part of my work day!

You're not sick man. I love watching NASA TV!!! I even asked my cable company if they had it, but they had no idea what the hell it was!! ..guess only us real fans know what it is.

I watch it all the time at work, online, that is:
www.nasa.gov/ntv/ntvweb.html.

Watch it! it ROCKS!

We have two space habitats now, MIR and the International Space Station. The history of the development of space habitats shows that, using current technology, we produce very high cost habitats that are dependent upon the Earth. O'Neill in his promotion of real space habitats makes it clear that to be built cost effectively, the material for their construction must come from someplace other than the Earth. That requires future technology.

Given current habitat dependence on earth, a civilization destroying asteroid, would presumably doom the crews on the station(s) as well. If the impact is not too large (sufficiently large to vaporize the oceans), then we should expect crews in submerged nuclear submarines to survive. Because they have long life power sources and extensive food stores, they would presumably be able to emerge someplace where even longer term energy resources are available (e.g. the Middle East). This would potentially allow them to construct green houses that could support a small population until the dust clears from the atmosphere. There are possible locations (deep valleys, underground facilities, etc.) that could survive the impact as well. Collectively, these would form the seeds of a new civilization. There are of course problems such as how do you identify locations where there are likely to be preserved the seeds, power sources, light sources, etc. in relative proximity that would allow you to maintain an agricultural base. But I think people could figure this out. It would be interesting to start a project that created a number of protected "humanity shelters" around the world that were widely know about just to be able to know we had a solution to the most probable doomsday scenarios.

Now, with regard to moving extensive numbers of people into space habitats or colonizing other planets with self-sustaining groups. This is going to require nanotechnology to be done cost effectively. If you have self-replicating systems based on nanotechnology (discussed by Josh Hall in this paper), then you can rapidly move people off the planet. You can also dissassemble a planet or two and build in the vicinity of ~100 billion telescopes the diameter of the moon. This array of telescopes would fill most of the inner solar system out to the orbit of Jupiter. At that point we would certainly be able to identify all of the Oort Cloud objects. Nanoprobes would then be launched to these objects using mass drivers. Once they arrive at these objects, they can be disasssembled into useful construction material and reoriented on orbits to deliver that material to useful locations. If objects were found that were on killer trajectories that could not be reformatted/redirected in time by the nanoengineers, then the mass drivers could also be used to deliver high velocity projectiles into the oncoming path of the object to deflect or vaporize it.

So the answer, as it is with most things, is we need molecular nanotechnology and self-replicating engineering systems. The last time I looked at some of the sites suggested, they did not include nanotechnology in their habitat development strategies. Without nanotechnology, the costs are likely to be so high that serious people can only consider them fantasies.

We have two space habitats now, MIR and the International Space Station. The history of the development of space habitats shows that, using current technology, we produce very high cost habitats that are dependent upon the Earth. O'Neill in his promotion of real space habitats makes it clear that to be built cost effectively, the material for their construction must come from someplace other than the Earth. That requires future technology.

Given current habitat dependence on earth, a civilization destroying asteroid, would presumably doom the crews on the station(s) as well. If the impact is not too large (sufficiently large to vaporize the oceans), then we should expect crews in submerged nuclear submarines to survive. Because they have long life power sources and extensive food stores, they would presumably be able to emerge someplace where even longer term energy resources are available (e.g. the Middle East). This would potentially allow them to construct green houses that could support a small population until the dust clears from the atmosphere. There are possible locations (deep valleys, underground facilities, etc.) that could survive the impact as well. Collectively, these would form the seeds of a new civilization. There are of course problems such as how do you identify locations where there are likely to be preserved the seeds, power sources, light sources, etc. in relative proximity that would allow you to maintain an agricultural base. But I think people could figure this out. It would be interesting to start a project that created a number of protected "humanity shelters" around the world that were widely know about just to be able to know we had a solution to the most probable doomsday scenarios.

Now, with regard to moving extensive numbers of people into space habitats or colonizing other planets with self-sustaining groups. This is going to require nanotechnology to be done cost effectively. If you have self-replicating systems based on nanotechnology (discussed by Josh Hall in this paper), then you can rapidly move people off the planet. You can also dissassemble a planet or two and build in the vicinity of ~100 billion telescopes the diameter of the moon. This array of telescopes would fill most of the inner solar system out to the orbit of Jupiter. At that point we would certainly be able to identify all of the Oort Cloud objects. Nanoprobes would then be launched to these objects using mass drivers. Once they arrive at these objects, they can be disasssembled into useful construction material and reoriented on orbits to deliver that material to useful locations. If objects were found that were on killer trajectories that could not be reformatted/redirected in time by the nanoengineers, then the mass drivers could also be used to deliver high velocity projectiles into the oncoming path of the object to deflect or vaporize it.

So the answer, as it is with most things, is we need molecular nanotechnology and self-replicating engineering systems. The last time I looked at some of the sites suggested, they did not include nanotechnology in their habitat development strategies. Without nanotechnology, the costs are likely to be so high that serious people can only consider them fantasies.

We have a skywatch, operated by the USAF's 21st Space Wing, called GEODSS. GEODSS constantly scans the sky with fully-automated 1-meter computer-controlled telescopes at multiple sites around the world. This system finds satellites, space junk, and anything else that isn't in the catalog of known objects. It's tied to NORAD, in case it detects an ICBM. This system has been operational since the 1980s. With the end of the Cold War, there are fewer hostile satellites to find, so some of the GEODSS sites have been turned over to civilian control and are now working on asteroid detection.

GEODSS is an impressive system. Among other things, it can detect dark objects when they obscure a star. It's even possible to use one of the telescopes with a laser to illuminate a low-orbit satellite so it can be photographed with a second telescope. Anything bigger than a basketball that hangs around Earth orbit for long will be picked up.

The Hawaii GEODSS site is now used for asteroid detection, as the Near Earth Asteroid Tracking program. Visit their site to see what they're picking up.

It was a miniature black hole, not some friggin' asteroid.

It was a stone meteorite, a conclusion reached in 1993 by three well-respected researchers and consistantly reaffirmed. OK?

Just a followup. The database is the NASA Aviation Safety Reporting System (ASRS), and the report on passenger electronic devices can be read here (PDF file).

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Apollo 12 landed on the moon 11/19/1969 and returned safely to Earth with Conrad, Gordon and Bean

Apollo-12 mission summary

There are many horrors lurking in our homes and offices. Perusal of this article (text-only link here) could lead you to live out your life in a tent. However the "big, bad three" ( formaldehyde, benzene and trichloroethylene) are largely scrubbed from the air by plants. The book referred to above looks at the most effective. You are correct in thinking that Chlorophytum comosum (Thunb.) Jaccques (The spider plant) is particularly useful. An important point is that plants are an effective, low-tech solution, self-replicating and aesthetically-pleasing - this beats expensive, quick-fix high-tech solutions any time.

It should come as no surprise that vascular plants do this so well as they have been cleaning earth's atmosphere for hundreds of millions of years (and much longer in the case of their predecessors).
- Derwen

oops, I hit "submit" instead of "preview". Here is my post correctly formatted.

What are the chances of ONE of those going dead, like in a laptop screen? More importantly, what's the return policy on dead-pixels in a camera?

It is extremely rare for a CCD-based (or CMOS-based) digital camera to have no bad pixels. Most (if not all) digital cameras automatically cover the dead pixels through interpolation. And with 1.2 to 3.4 million pixels per image, you probably won't notice if a a small number of pixels are interpolated. If you wanted to purchase a 1 megapixel CCD with no bad pixels, expect to pay around $25,000. Nasa is developing a new type of CMOS based sensor, called APS (Active Pixel Sensor). Among other goals, it aims to increase the yield of perfect samples. See this page for more information.

That's interesting... True, I can see the interprolation hiding defects. So then the chip is not used on a 1-by-1 ratio, pixel for pixel?

What are the chances of ONE of those going dead, like in a laptop screen? More importantly, what's the return policy on dead-pixels in a camera? It is extremely rare for a CCD-based (or CMOS-based) digital camera to have no bad pixels. Most (if not all) digital cameras automatically cover the dead pixels through interpolation. And with 1.2 to 3.4 million pixels per image, you probably won't notice if a a small number of pixels are interpolated. If you wanted to purchase a 1 megapixel CCD with no bad pixels, expect to pay around $25,000. Nasa is developing a new type of CMOS based sensor, called APS (Active Pixel Sensor). Among other goals, it aims to increase the yield of perfect samples. See this page for more information.

The array of visible telescopes is what the NGST is about (to some extent-it uses segmented mirrors acting as one). More directly, the Space Technology 3 mission is supposed to address this.

The array of visible telescopes is what the NGST is about (to some extent-it uses segmented mirrors acting as one). More directly, the Space Technology 3 mission is supposed to address this.

Sucessful launch...YEAH BABY!! click here Nasa shuttle site

AARGH! Hit the wrong button. Let's try again...

Ultimately, the scariest aspect of this is to be reminded we don't have an organized program monitoring for killer asteroids.

Didn't you follow the link to the NEAT project? What do you think found THIS one?

You might argue that it's underfunded, will take too long, might miss something significant, might not spot a collider in time to do something about it, or that it will only spot asteroids and not comets (or at least not in time).

But I recall a decade ago when we DIDN'T have such a project in place AT ALL and I'm MUCH happier with the current situation.

Every time they spot a new one that comes anywhere near close enough they get another opportunity to publish an estimate of the number they HAVEN'T found. A nice argument for a few more bux for telescopes and observers.

Just think: If we stop one extinction-event rock, humans and technology will have prevented vastly more environmental damage in a single operation than has been caused by all the humans since we first appeared. Take THAT, Earth First!

Ultimately, the scariest aspect of this is to be reminded we don't have an organized program monitoring for killer asteroids.

Didn't you follow the link to the ? What do you think found THIS one?

You might argue that it's underfunded, will take too long, might miss something significant, might not spot a collider in time to do something about it, or that it will only spot asteroids and not comets (or at least not in time).

But I recall a decade ago when we DIDN'T have such a project in place AT ALL and I'm MUCH happier with the current situation.

Every time they spot a new one that comes anywhere near close enough they get another opportunity to publish an estimate of the number they HAVEN'T found. A nice argument for a few more bux for telescopes and observers.

Just think: If we stop one extinction-event rock, humans and technology will have prevented vastly more environmental damage in a single operation than has been caused by all the humans since we first appeared. Take THAT, Earth First!

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Anyway, it seems pretty clear that the meteorites are from Mars, though it is slightly less clear for the meteorite which they claimed might have life (that's a hypothesis that is far from proven) as this article explains.

Also, here's a really nice bibliography on Martian Meteorites for those looking for some light reading.

Of course, the matching could be done rapidly by computer, then checked by people. With the knowledge of where the balloon was launched, you could narrow down the search area too. Then each "fix" would allow extrapolation of where the next photos come from, and so on.

This system, of course, is part of Zubrin's "Mars Direct" philosophy which claims that Lunar bases and other $$$ things are not prerequisites for a crewed Mars mission. He would probably include a "Martian GPS" like Marsnet in his "unneccessary" list.

Wat it means, is that balloons become simpler and easier. You can now imagine a lander carrying half a dozen balloons with 1kg payloads that get released one by one. One problem with baloons though is tracking, for good science data, you need to know what the readings are and where they where taken. Until something like Marsnet is up and running, the full potential of balloons won't be fulfilled

With all the posts about LEO (Low Earth Orbit) and GEO (Geosyncronous Earth Orbit) I took the liberty of diging up an old link you might find enlightning. Point your java enable web browser here and you'll see just how high up a GEO is, and thus how much latency such a system will have.

• 
  An energy gradient (i.e. "an organized", dense energy source near an "energy sink" so living things can grab that energy and use it)
  
• 
  The ability to reproduce (share traits with the next "generation")
  
• 
  Responds to stimulus
  

• 
  Water
  
• 
  Carbon
  
• 
  Nitrogen (Can be ammonia or NH3)
  

Actually, its in Hampton, VA which is near Virginia Beach. I got the same vibe when I saw 'Langley', 'Virginia' and 'Government Research' all in the same article.

You can learn more about the research center through this nifty Shockwave-based Interface.

How is Europa's size compared to Earth's or Luna's? With this discovery, could this be a comfortable place for people to live (with water and all)?

Europa's diameter is 3,138 km (1,946 miles), just a bit smaller than Earth's moon.

The surface gravity is also slightly less than that of our moon, which is 1/6 Earth gravity. That wouldn't stop people from living there, but the fact that the entire surface is ice would make it a bit, well, slippery.

I know it's far away, but how does it compare to Mars?

Europa isn't really comparable to Mars in many ways. Mars has an atmosphere -- thin and unbreathable, but much more substantial than vaccuum. Also, being much closer to the sun, Mars would have more energy available for things like growing plants and generating power from wind and sun.

On the other hand, I suppose that Europa's oceans (assuming they exist) could be more hospitable than the surface! Anything's possible... especially when monoliths are involved. :)

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Your accusations of bias are completely unfounded. The paper discussing the results of the '99 contest clearly states the objective criteria used to determine the winners. Entries were judged first on code correctness - each entry had to correctly process all of the test samples. The prize then went to the entry that produced the most highly optimized output. In other words, the prize went to the the entry that objectively produced the most correct and efficient code.

The winners of the '98 contest were simply the best players of the game. What could be more objective? As far as the Judges' Prize is concerned, the contest announcement very clearly states:

Finally, the Judges' Prize is to be awarded, not on the basis of the competition, but solely at the whim and discretion of the judges. Novel algorithms, interesting languages, beautiful code, arresting user interfaces, use of parallelism -- these things may well count for something in the judges' eyes.

This is clearly a subjective decision, but the contest organizers make it very plain that this is the case.

You could perhaps argue that the choice of problems that involve complex translation or problem-solving show a bias towards functional languages, but the fact of the matter is that you'd have a hard time coming up with a good high-level programming problem that wasn't better attacked with a functional language. The winners give much more lucid accounts of the advantage of functional languages for complex problem-solving than I could hope to. They're worth reading.

Another interesting recent study explored the productivity advantages of lisp over C/C++ or java. Their conclusions are also very interesting.

ISS *is* in "really low orbit" (about 400km), as a consequence it orbits earth every 90 minutes. You can see its path and realtime position here (need Java enabled).

http://spaceflight.nasa.gov/gal lery/images/station/

Back to what I set out to say, there are many temperature series out there. Some of them go back over one hundred years. Reliable global temperature series don't seem possible in the pre-satelite era. Yes, many European cities have temperature series going back way further than that, and we have cores from the Greenland icecap which give us hints about the local-to-Greenland weather for hundreds of thousands of years. There is still some controversy about the conclusions to be drawn from them.

Here are a couple of links:
National Ice Coring Lab This has some ice core data sets, and some perspective on them.

Global Climate Perspectives System These guys have some models and some data up on the web.

Global Temperature Anomolies" This is a NASA site...

This is a fellow who seems to take it as given that the temperatures have increased (I'm still not convinced), but isn't sure about why.

Here is a site put up by some folks who aren't convinced by the popular press coverage of global warming.

I know I've found some much more usefull links in the past, but I can't stumble over them right now. One thing that you want to keep in mind is that ( according to researchers I've talked to) being trendy is vital to getting grant money. If the politicians and the bureaucrats they fund are convinced that global warming is politically significant, you base your grant proposals on the idea that global warming is real, even if the really interesting questions start from another premise. Or, you don't get funded. So while I won't say that anyone is whoring for grants, I will say that the scientific debate might be on rather different terms if it weren't for politics.

The archives are at http://nmp.jpl.nasa.gov/ds1/archives.html and date back to October 1998.

JPL's main website (www.jpl.nasa.gov) also has lots of links to their other projects.


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The archives are at http://nmp.jpl.nasa.gov/ds1/archives.html and date back to October 1998.

JPL's main website (www.jpl.nasa.gov) also has lots of links to their other projects.


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• Antimatter and Fusion for rocket propulsion
• NASA Advanced Space Transportation Program
• NASA Breakthrough Propulsion Physics Program

Now manipulating neutrinos is really hard - most of them pass right through earth without noticing it.

• Antimatter and Fusion for rocket propulsion
• NASA Advanced Space Transportation Program
• NASA Breakthrough Propulsion Physics Program

Now manipulating neutrinos is really hard - most of them pass right through earth without noticing it.

• Antimatter and Fusion for rocket propulsion
• NASA Advanced Space Transportation Program
• NASA Breakthrough Propulsion Physics Program

Now manipulating neutrinos is really hard - most of them pass right through earth without noticing it.

The New Scientist article
Marshall Space Flight Center PDF file

yes, you're right, it seems i was. i'm glad you responded anyway; you asked some good questions.

i got my data from Helen Caldicott, founder of Physicians for Social Responsibility, regarded by some as an extremist (read: aggressively radical), regarded by others as aggressively logical, regarded by many as an irritant. I could not re-find the original citation, & so was forced to make do with information from the Agency for Toxic Substances and disease Registry. This site does paint a much less grim picture: it states that 1400 pCi/kg body weight causes bone cancer in 4 years. A pCi is equivalent to one-billionth of an mCi; one mCi of plutonium 239 weighs .016 grams. I'm assuming NASA used Pu -239, not Pu -238, which has a much higher toxicity (one mCi weighs .00006 gm). So the upshot is 2.24-8 g/kg body weight is enough to give a person bone cancer in 4 years & therefore .00000152 grams would be carcinogenic to a 150 lb (68kg) person.

nonetheless, that same site lists the Annual Limit on Intake of Pu-239 as 20,000 pCi, which is equivalent to 3.2-7 g, or three millionths of a gram. It does not, however, say what the result of exceeding this limit would be.

Yet NASA's Final Environmental Impact Statement warns of the dangers of "inadvertent reentry," stating that if the Cassini disintegrates, dispersing the plutonium, "5 billion of the estimated 7 to 8 billion world population at the time ... could receive 99 percent or more of the radiation exposure." This condition would necessitate the banning of future agricultural land use and the permanent relocation of the population in any affected urban area.

Originally I had thought that solar power was a viable alternative. Visiting the European Space Research and Technology Centre shows that it is not.

I suppose that now is the time to hang the tie-dyed dancing teddy bears, but it seems to me that if the best safe option is not feasible, perhaps the mission should not be flown at all. The risk of a necessary "permanent relocation" of entire urban areas seems unacceptable to me, especially if we are still theoretically practicing democracy.

As far as the media goes, I think media outlets--especially the conglomerates, or the ones owned by conglomerates--generally hesitate to dig into little-known government scandals, since the government is one of its main sources of information. For instance, a reporter can simply report verbatim what a government agent has said, and feel secure in not verifying it. (I have done the same thing above, perhaps naively).

Civilian reports, on the other hand, require research and verification, which is time-consuming and expensive. Therefore reporters lean towards government sources since it is more expedient and generally puts them in a better light with their bosses, since they don't have to authorize unusual expenditures. Smaller for-profit venues don't have the funds for extensive investigations; not-for-profits are anomalies to be commended.

I do not think this is a conspiracy theory; i think it is simply the result of businesses doing what businesses do, which is attempt to make money. I'm probably safe in saying that media corporations are still corporations, which have as their explicit goal the accumulation of capital.

Everytime someone badmouths Linux its a feature here, while lots of interesting stuff is ignored. How about the new ISS module Progres s?

Mod this down, I've got lots more Karma than you.

Actually it appears you are trolling, but I'll bite anyway (its late :) ).

1) I have heard of Cassini, it is an intersting exploration probe of the Saturn system. As an aside where do you get your Pu toxicity data? Here's a link to a paper on the subject by Bernard Cohen. Do you have information from a radiation health researcher to back your claims?

2) In order to expolore the outer solar system there are good reasons to use plutonium as a power source (in an RTG, Radioisotope Thermal Generator). It is compact (low mass/energy), long lived, and reliable. Other possible power sources have inherently serious problems.

3) Also they do contain the Pu in many layers of protection in case of an accidental reentry to prevnt the release of the Pu in the atmosphere. Perhaps the press has been "nonchalant" because the danger is miniscule and only the extremists are upset by a non-existant danger.

AFAIK in Fl. at least being a "right to work" state, it's quite possible that his firing had 'nothing to do' with his whistlebowing activities.

Hey bud, Marshall Space Flight Center is in Alabama, not Florida, and while IANAL, I don't know that right-to-work statutes would apply here. I don't even remember if AL is right-to-work.

GFM -- who can see a big-ass Saturn V from his bedroom window . . . I live two miles down the road and have to go out there today. =)
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• rover (highrez )
• rover (lowrez)

LinuxLover

• rover (highrez )
• rover (lowrez)

LinuxLover

For those who don't know, safety is always spelled with a capital S in and around NASA. Their homage to this sacred cow -- mandatory monthly meetings with cliff-hanger videos that make the American Red Cross look like Cannes Film Festival triumphants, monthly inspections by overbearing site safety managers, some inane safety tip in email at least weekly from same -- borders on asinine.

If AJT doesn't get a sound smacking, there's probably a rat somewhere in the chain of their contract.

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Since the VLT source appears to be slashdotted, another good place to look is the Astronomy Picture of the Day, which has a Hubble pic of the comet up today.

Doug

You might have a look at encke. This site has a lot of info about comets in general, including finding charts, positions, brightness, and lots of pictures spread across the site.