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I don't think the action of CFC's as a catalyst to break up ozone in the presence of UV radiation is under dispute here, it is not a controversial experiment.

Nor is the fact that CFC's take quite a while to degrade. CFC acts as a catalyst, meaning it participates in the reaction, but is not comsumed. Typical figures are one CFC molecule will survive for long enough to destroy 100,000 ozone molecules. All of this is pretty basic stuff which you could easily find out with 5 minutes of googling.

The upshot of this is that a small amount of CFC's reaching the upper atmosphere produces a tremendous amount of damage. Ozone is naturally created, but if the rate of destruction is too high, then clearly the ozone levels will fall.

In my last post I put some URL's of some tables and graphs. I suggest you study them closely, and decide for yourself if it is natural or not.

Since you seem too lazy to do your own research, or even lookup posted URL's, I post here a table of world CFC production from 1940 to 1990 (from http://arch.rivm.nl/env/int/hyde/eisp_cfc.html

CFC-11 output, millions of killograms
1940: 0.1
1945: 0.3
1950: 5.5
1955: 23
1960: 40.5
1965: 108.3
1970: 206.6
1975: 310.9
1980: 250.8
1985: 280.8
1985: 216.1

I can't be bothered re-typing the data for CFC-12, it is similar (but higher), look it up yourself (you do know how to click on a URL, don't you???)

Remembering that each CFC molecule will destroy 100,000 or so O3 molecules once it reaches the upper atmosphere, and the units here are millions of killograms, I leave it for you to calculate the potential damage. Exactly how much ozone do you think there is?

Please go and do some research and some thinking, and by all means post again if you can come up with some actual refutations of what I've been saying. So far you have shown absolutely nothing except whining, in response to hard evidence and figures.

The astronomy picture of the day a few days ago had a nice moving picture of Jupiter with two moons. Where did the other 46 go?


(feeble Karma saving attempt)

Recent results from Galileo indicate that Callisto and Ganymede may also have vast oceans beneath their surfaces. So ruling out Europa doesn't mean that there is no life in the Jovian system.

...it uses a super-low density foam type material...

Maybe they used aerogel?

But yeah, something could go wrong. Wah. Let's forget about it and all stay on Earth until the sun explodes.

Accoding to this article from NASA, Ion engines don't create anything near 1g of thrust. In fact, the acceleration is so slight that scientists have to test in a vacuum to measure it. Like you mentioned, they get their efficiency from the speed of the ejected ions, however this article states that 80 kg of fuel would last 1 to 2 years and could accelerate a rocket up to 22,000 mph.

And for propellantless propulsion we have the space tether, solar sails, and (for a good laugh) vacuum propellers which are big props that are supposed to push against the 'quantum vacuum'.

Accoding to this article from NASA, Ion engines don't create anything near 1g of thrust. In fact, the acceleration is so slight that scientists have to test in a vacuum to measure it. Like you mentioned, they get their efficiency from the speed of the ejected ions, however this article states that 80 kg of fuel would last 1 to 2 years and could accelerate a rocket up to 22,000 mph.

And for propellantless propulsion we have the space tether, solar sails, and (for a good laugh) vacuum propellers which are big props that are supposed to push against the 'quantum vacuum'.

Maybe you should look at your own link Take a close look at that picture. There are exactly two non-Russian European components.

From the Astronomy Picture of the Day:
Sputnik

Doug

Lt Col Virgil Grissom USAF, Lt Col Edward White USAF and Lt Cdr Roger Chaffee USN. All died, as a previous poster stated, in the Apollo 1 fire in 1967. Apollo 1

On the friendly fire issue - no, not yet. The Canadian casualties (Canada's first combat losses since Korea) were in Afghanistan. Friendly Fire in the Afgan Campaign

In Iraq the US has only yet managed to kill American, French, British and Turkish personnel. Operation Provide Comfort

I watch as everyone jumps on the bandwagon that the United States' space program sucks. All because we have not returned to the moon.

Okay, our manned missions have become fairly lax, but NASA's unmanned missions are doing a fair job of making up for it. Just check the current list: http://www.nasa.gov/missions/current/

Plus, the Hubble and Chandra are doing real good work - in Earth orbit.

Nice page on what else is going on with space missions...

If you want to know what parts of the ISS the US has assigned to other nations, you can find it on Google (e.g., this and this). Ariane rocket launches also are used for a lot of components, although US media don't seem to have much interest in reporting this (e.g., here).

The main reason for NASA to favor international involvement in something like the ISS is because it makes it harder for Congress to cancel the project; otherwise, it looks like they'd just as soon go it alone.

Deep Space 1 used an ion thruster.

Ion Thruster Used to Propel the Deep Space 1 Spacecraft to Comet Encounters

There were two, Luna and Zond. (See that link if you trust the federal government). The Soviet missions ran from 1959 to 1976 overall; Luna was the ground mission which picked up three lunar ground samples (Luna 16, 20, 24) and Zond was the satellites that flew over the moon (probably trying to set up a laser defense array or something).
The important thing isn't that moon travel has happened before; it's that it's being seriously considered again.

2) Globus is fucking trivial to install (and I'm not on their staff). Maybe not as easy to install as kazaa, but then gridware is targetted at people who want to do more with the internet than look at pictures of Gillian Anderson's pussy. That said, review point one. There are other grids available.

Posted anonymously since I, too, am involved in a grid project.

Globus *IS* a pain in the ass to install. And I don't trust it in the least. Big clumps of scientist-written code running as a privledged user on a high-profile network. Stupid non-standard install and build scripts that ignore where I tell it perl lives. It *IS* a multi-day install even if you know what you're doing.

The emperor has no clothes. In a typical political environment grid computing is nothing more than a method of transferring resources from projects with funding to projects with no funding.

I also think that you dismiss manned spaceflight to readily. While there are some things that robotic probes can do better, there are times when decidely human qualities win out.

The Soviet Union was the first (1959) to splatter their flag onto the moon's surface as described here:

Luna 2 was the second of a series of spacecraft launched in the direction of the Moon. The first spacecraft to land on the Moon, it impacted the lunar surface east of Mare Serenitatis near the Aristides, Archimedes, and Autolycus craters. Luna 2 was similar in design to Luna 1, a spherical spacecraft with protruding antennae and instrument parts. The instrumentation was also similar, including scintillation- and geiger- counters, a magnetometer, and micrometeorite detectors. The spacecraft also carried Soviet pennants. There were no propulsion systems on Luna 2 itself.

They were also the first to soft land a probe (Luna 9 in 1966). Maybe they're the ones with the valid claim.

The Soviet Union was the first (1959) to splatter their flag onto the moon's surface as described here:

Luna 2 was the second of a series of spacecraft launched in the direction of the Moon. The first spacecraft to land on the Moon, it impacted the lunar surface east of Mare Serenitatis near the Aristides, Archimedes, and Autolycus craters. Luna 2 was similar in design to Luna 1, a spherical spacecraft with protruding antennae and instrument parts. The instrumentation was also similar, including scintillation- and geiger- counters, a magnetometer, and micrometeorite detectors. The spacecraft also carried Soviet pennants. There were no propulsion systems on Luna 2 itself.

They were also the first to soft land a probe (Luna 9 in 1966). Maybe they're the ones with the valid claim.

Owned by no nation per international treaty

Article II Outer space, including the moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means.

The point about manned spaceflight is irrelevant, it is like saying that the New Yorkers can't build the tallest skyscraper until they have duplicated the great pyramid. The justification for manned exploration is pretty tenuous at this point, we now have robots that do the job better. The Appolo missions were about winning the cold war, science was a byproduct.

China is persuing this project for political reasons too. It is a Jim Collins style Big Hairy Audacious Goal, the whole point is that it is hard. But China wants to do it to prove it is a major power and that the US and others should not underestimate them.

I've read about nuclear-explosion-powered space ships before. Project Orion, in the '60s, was a serious attempt at this. google for more links.

The initial cost of each shuttle comes from NASA, John Glenn, PBS/NOVA and Sandia National Laboratories. They're all in agreement except for the price of Endeavour, in which three of the four sources list $2.1 billion and NASA claims $1.7 billion.

The $450 million per flight number comes from NASA. See this link for details.

The $1 billion amortized launch expense 1977-1993 comes from Aviation Week Forum on Compu$erve, 26 July 1993.

It's really amazing to me that the question is even arising; take a look at the archived project page for the Delta Clipper ; this is such an obvious solution, low cost, high sustainability, and it's really cool. Aside from the blowing up thing, of course.

While they claim that the X-series they are currently working on is just the latest incarnation, that's a bunch of crap; the big contractor corps just don't like the idea of a cheap spacecraft.

It's either this or Prometheus; anything else is just a temporary solution.

It's really amazing to me that the question is even arising; take a look at the archived project page for the Delta Clipper ; this is such an obvious solution, low cost, high sustainability, and it's really cool. Aside from the blowing up thing, of course.

While they claim that the X-series they are currently working on is just the latest incarnation, that's a bunch of crap; the big contractor corps just don't like the idea of a cheap spacecraft.

It's either this or Prometheus; anything else is just a temporary solution.

The microwave radiation is blueshifted in the direction our galaxy appears to be moving in relation to points at the edge of the visible universe, after correcting for blueshifts from our motion around the sun and the sun's course through the galaxy. This rather handily shows the source of the microwave radiation to be outside our galaxy. If you blame it on the instruments themselves, then you have to come up with a theory that explains how the instruments produce anomolous readings that correspond exactly with the extra-galactic point they happen to be aimed at at the moment (versus what planet, local star, geomagnetic longitude, etc. they are pointed at). And the source of the microwaves isn't claimed by astrophysicists to be "distant stars everywhere." It is obvious that you don't know enough about the theories or the instruments and observations that stimulated them to discount them. Part of science is to come up with theories that explain observations. No where is it implied that the theories have to be whole and perfect or even correct, just that they explain all the evidence gathered so far. If we could send probes to distant galaxies and they showed that the Milky Way was responsible for all the microwave radiation, then the theories would be rewritten and /. user Angram crowned as a visionary. But don't hold your breath.

Consider though the design and launch of such a thing will train another group of engineers in the art of spacecraft design. There are still many of us, now in our 50's and 60's that originally designed a lot of the missions when they were popular in the late 70's, but we are aging.

While I appreciate that keeping the engineering teams trained is a good thing and I'm in no way against this particular mission, I was wondering if you could please clarify what you're saying here.

Specifically, is there any reason why the engineering teams need to be trained up on a mission going to the Kuiper belt? There's hardly a lack of current and future JPL missions that involve sending probes to other bodies in the Solar System.

Consider though the design and launch of such a thing will train another group of engineers in the art of spacecraft design. There are still many of us, now in our 50's and 60's that originally designed a lot of the missions when they were popular in the late 70's, but we are aging.

While I appreciate that keeping the engineering teams trained is a good thing and I'm in no way against this particular mission, I was wondering if you could please clarify what you're saying here.

Specifically, is there any reason why the engineering teams need to be trained up on a mission going to the Kuiper belt? There's hardly a lack of current and future JPL missions that involve sending probes to other bodies in the Solar System.

What about the gravitational pull of the Sun? Does Pioneer 10 have enough velocity to escape its pull?

Yes.

That's like comparing the failure of an entire airplane to the failure of the black box inside the airplane. Also, there are different kinds of heat shields, reusable ones (like the tiles on the shuttles) and ones that desintegrate in the process (like the ones used on the reentry capsules on the Apollo missions). When you have a solid object surrounded by enough material to withstand re-entry two times over, I would say that is sufficient to prevent the vaporization of the core material in the atmosphere under any circumstances. BTW, there's not a single soul at NASA that believes an RTG could even possibly lead to a single fatality (unless you're the unlucky guy that gets hit in the head by it). Consider how indestructable black boxes in airplanes are and then multiply by 100 and you'll get an idea of how sturdy these things are. Also, this is all going off the premise that either a) the rocket blows up on launch (which absolutely wouldn't have enough energy to harm the RTG) or b) the RTG burns up in the atmosphere on a botched gravity assist maneuver using the earth. The Pluto mission might not even reorbit earth and just head straight out to Jupiter (that's my bet as they are really cutting it close and probably don't have the time to try an earth gravity assist to reach Jupiter before getting to Pluto).

it's perfectly fine to kill thousands or tens of thousands of people as long as nobody knows that you did--otu of sight out of mind

In which scientific report did you read that stated several kilograms of plutonium in an RTG could kill thousands of people??? Before replying (if you reply) check out this site. Here's a direct quote on its safety design:

The DOE has demonstrated that RTGs will minimize the possibility of fuel release during the generators' lifetime, particularly in the event of an accident. The very low probability of a plutonium release results from the protective-layering design of a spacecraft's RTGs. The radioisotope energy source for the GPHS-RTG is a stacked column of 18 individual GPHS modules. Each module consists of a graphite aeroshell, two-carbon-bonded carbon fiber (CBCF) insulator sleeves, two graphite impact shells (GISs), and four fueled clads. The graphite (carbon-carbon composite) aeroshell serves as the module's primary heat shield to protect the internal components from direct exposure to a reentry's thermal and aerodynamic environment. The two GISs contained in each GPHS module provide the primary resistance to impact or mechanical loads. Each GIS assembly is thermally insulated from the aeroshell by a low thermal-conducting CBCF insulator sleeve. Each fueled clad, separated by a graphite floating membrane, consists of one fuel pellet of ceramic (or solid) plutonium dioxide encased in an iridium shell. The iridium shell protects and immobilizes the fuel. The iridium alloy is compatible with the plutonium dioxide fuel material, resists oxidation to air and has a high melting temperature. Each clad also contains a vent designed to release the helium generated by the alpha particle decay of the fuel. The protective layers are specifically designed to safeguard the plutonium from fires, explosions, fragment impacts and the heat of atmospheric re-entry.

Light sailing works well for inner planet missions and for activities extending out to the Mars orbit. However, the solar flux falls off as the inverse square of the distance from the sun. Thus for missions beyond the Jupiter orbit, an alternative to solar propulsion is to use directed light from a high power laser.

I don't know of anyone who has tried using a laser for deep space propulsion. There's also the little matter of how do you stop once you reach Pluto. Since you're on a hyperbolic (or very elliptical) orbit to get there, you'll need a pretty large delta V (change in velocity) to slow down to the crawl that Pluto is travelling at. With ion propulsion or solar sails (using high powered earth lasers), you would need to accelerate for half the trip and decelerate the other half. Although it's possible that this could be faster than rockets (if the accleration was great enough), it wouldn't be if using current technology, especially when you consider the extra velocity a rocket-propelled spacecraft will get from a gravity assist from Jupiter if launched soon.

I think ion propulsion may also be a good choice for a long-range mission such as this. I don't know if NASA has enough confidence in it yet to stake a mission of this magnidute on it, but the Deep Space 1 project was very successful despite some early glitches.

That aside, I hate space exploration. I want our problems solved first.

Yeah, because nothing useful
has ever come
from space research. Jesus man, science for the sake of science is what got our civilization to the advanced state is in today. You don't know the impact space technology has had on your and my life.

Until we develop the tech to do it right, Blow it off.

Yeah, Nasa oughta just sit on their asses until one day the one true idea strikes them and they figure out how to do it right. This is how they figure out how to do it.

When the system is found succesful NASA plans to use it in future probes, like the Interstellar Probe. That thing would travel 200 AU (Astronomical Units) in 15 year. Much faster than the Voyager and Pioneer crafts.

Another, more controversial, propulsion system is Nuclear propulsion. Technical information can be found here

When the system is found succesful NASA plans to use it in future probes, like the Interstellar Probe. That thing would travel 200 AU (Astronomical Units) in 15 year. Much faster than the Voyager and Pioneer crafts.

Another, more controversial, propulsion system is Nuclear propulsion. Technical information can be found here

First reference that sprang to hand

Kennedy Kennedy said that we choose to do these things not because they are easy but because they are hard.
Not that I disagree with you about priorities. President Bush Sr. set the Kennedyesque goal of landing humans on Mars by 2019, the 50th anniversary of the lunar landing. I'd say that's on the back burner until we master putting people in Earth orbit and returning them safely to the ground.

Wait a minute, not everything from the current era is "bad engineering." Remember Galileo? Galileo was launched in 1989, was designed to operate until 1997, and they're finishing up the tour now. I'd call that a good job. NASA, keep up the good work. And remember, meters != feet!

Wait a minute, not everything from the current era is "bad engineering." Remember Galileo? Galileo was launched in 1989, was designed to operate until 1997, and they're finishing up the tour now. I'd call that a good job. NASA, keep up the good work. And remember, meters != feet!

6. Government End Users. If you are acquiring the Software on behalf of any unit or agency of the United States Government, the following provisions apply. The Government agrees:

(i) if the Software is supplied to the Department of Defense (DoD), the Software is classified as "Commercial Computer Software" and the Government is acquiring only "restricted rights" in the Software and its documentation as that term is defined in Clause 252.227-7013(c)(1) of the DFARS; and

(ii) if the Software is supplied to any unit or agency of the United States Government other than DoD, the Government's rights in the Software and its documentation will be as defined in Clause 52.227-19(c)(2) of the FAR or, in the case of NASA, in Clause 18-52.227-86(d) of the NASA Supplement to the FAR.

There's quite a lot of technical info on it here . I dunno about the signal strengh but the data rate was running at a scorching 16bps (compared to around 2kbps near jupiter) at it last encounter, easily rivaling that of a slashdotted site.

there is some closed ecosystem research going on, check e.g. BIO-Plex at http://pet.jsc.nasa.gov/

i think at the moment they have some loops closed and a 50% closed food loop - first 100% closed test coming next year or so.

it isn't much, i agree, but at least something is being done.

eetu.

Voyager, not Pioneer, took a "Golden Record" with encoded images, spoken greetings in dozens of languages, a variety of natural and human sounds, and an anthology of music from around the world, including both classical (e.g. Bach) and popular (e.g. Chuck Berry) selections.

The record is 12 inches in diameter and plays at 16 2/3 r.p.m. The long-playing record of the day played at 33 1/3 r.p.m., but Carl Sagan's committee had the foresight to predict that advanced extraterrestrials would get double the music by playing their LPs at half the speed.

Just kidding. Sagan's committee included instructions for playing the record, and even a phonograph needle cartridge. I hope the species that finds it has ears.

Voyager, not Pioneer, took a "Golden Record" with encoded images, spoken greetings in dozens of languages, a variety of natural and human sounds, and an anthology of music from around the world, including both classical (e.g. Bach) and popular (e.g. Chuck Berry) selections.

The record is 12 inches in diameter and plays at 16 2/3 r.p.m. The long-playing record of the day played at 33 1/3 r.p.m., but Carl Sagan's committee had the foresight to predict that advanced extraterrestrials would get double the music by playing their LPs at half the speed.

Just kidding. Sagan's committee included instructions for playing the record, and even a phonograph needle cartridge. I hope the species that finds it has ears.

Voyager, not Pioneer, took a "Golden Record" with encoded images, spoken greetings in dozens of languages, a variety of natural and human sounds, and an anthology of music from around the world, including both classical (e.g. Bach) and popular (e.g. Chuck Berry) selections.

The record is 12 inches in diameter and plays at 16 2/3 r.p.m. The long-playing record of the day played at 33 1/3 r.p.m., but Carl Sagan's committee had the foresight to predict that advanced extraterrestrials would get double the music by playing their LPs at half the speed.

Just kidding. Sagan's committee included instructions for playing the record, and even a phonograph needle cartridge. I hope the species that finds it has ears.

I think you mean Deep Space 1, which has an ion engine and flew within 1,400 miles of comet Borelly. A little extra duty for that spacecraft, not unlike Pioneer greatly exceeding expectations. The one that landed on an asteroid was NEAR Shoemaker, but it has normal thrusters. Both where extraordinary missions.

I have been reading a history book called The Space Shuttle Decision for some time because I wondered how they ended in that piece of crap and I can see that it wasn't the "dedicated young engineers" doing the work even in late 60s. You can see that NASA was a political tool from the start.

NASA was always ran by "politicians", from the start to the end. It was a political tool when it transferred from being NACA to NASA and it is still a political tool to spend more money.

Human space travel might have been managed in a much better way, no argument and definitely space science would be much better without NASA spending all its money on bureucracy and making contractors in Boeing etc. rich. Read the NASA History books for their shame value. Although they do best to paint a rosy picture, if you can read the lines, you will be disgusted with NASA for the rest of your life.

No, but this page has some fascinating artist renditions (and *huge* publication size images), including Pioneer passing Jupiter, and the Pioneer looking back at the sun from Neptune's orbit!! Amazing! Nobody's ever seen *our* sun appear so small. (It's more dramatic in the medium-size picture.) It gives me goose bumps thinking what it would feel like to be out there, lost in the bleakness of space.

I am saddened to hear that we lost contact with Pioneer 10 because we don't understand the forces acting on it. One would think that since we know gravity pretty well, and we know the relivant masses involved, we could predict the motion of the Pioneer satelites. Alas no. Exotic things like dark matter and photon pressure were invoked to explain the extra attraction (back) towards our sun, and failed. I heard a great talk about this while at U.C. Riverside department of Physics and had the chance to ask about photon pressure myself (yes, they take that into account - it is a far, far larger effect than this). The BBC has an old story on this effect, which I am sure many slashdotters have already heard of, here.

By the way, a similar anomoly is seen in Pioneer 11 and another distant satelite (Ulysses perhaps???).

Also, there is a link at nasa.gov, but at this time it seems broken. I include it for completeness here.

It seems John Anderson and friends have written several articles on this. One which you might find interesing has been published in Physical Review D: here.

I only wish I were as elegant in wording as Carl Sagan:

Reflections on a Mote of Dust

We succeeded in taking that picture, and, if you look at it, you see a dot. That's here. That's home. That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species, lived there on a mote of dust, suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and in triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of the dot on scarcely distinguishable inhabitants of some other corner of the dot. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light.

Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity--in all this vastness--there is no hint that help will come from elsewhere to save us from ourselves. It is up to us.

It's been said that Astronomy is a humbling, and I might add, a character-building experience. To my mind, there is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly and compassionately with one another and to preserve and cherish that pale blue dot, the only home we've ever known.

-- Carl Sagan (1934-1996)

You can see the image referred to in the article here .

(In all honesty, I believe this image was from Voyager, but Pioneer had the same view and I felt it only appropriate.)

Fare well, Pioneer.

Are you going to be dead in 2020? The New Horizons project aims to launch a probe in 2006 to explore Pluto and the Kuiper belt.

The Voyager 1 probe is more distant than Pioneer 10, and will probably expire within 20 years.