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Delaying Our Visit To The Last Planet
O.F. Fascist writes: "Story over at Space.com about how the first NASA mission to Pluto might get cancelled for a variety of reasons." Sounds like the reasons at play here are good, though -- "reliable transport required" applies to multi-year interplanetary journeys, too. (And what are we looking for on Pluto again?)
Well.. It might be for the better they just scrap the whole thing and let someone else take over. Since they don't seem to have gotten past the metric conversion problems that ruiend the last Mars mission. Just look at the article:
;)
"Pluto is also the smallest - just 2,300 miles (1,400 kilometers) in diameter."
Since when is miles a smaller unit then klicks? Noe if they switched around those numbers they would still be off a bit. But not by much
Cheetos.
Pluto is speculated to house the world's largest naturally-occuring supply of Cheetos, which due to it's unique chemical and thermal conditions occur in both original and crunchy varieties.
Of course, Cheetos are just the easiest Plutonian resource for us to extract. Researchers have speculated that there may be literally millions of Brittany Spears CDs, Teletubbies dolls, and other objects of highly marketable value to our advanced society.
Of course, there is some concern that we'll have to scrape away layers of frozen methane, abstract scientific research, technological challenge, impact crater detrius, and new knowledge of our universe, before we can get to even the most shallowly buried N'Sync singles; but isn't it worth it to try?
Christopher A. Bohn
cb
Oooh! What does this button do!?
(And what are we looking for on Pluto again?)
a damn cold place to stick racks and racks of overclocked Abit BP-6 dual celeron systems. pluto would be ideal. dare i say it...a beowulf cluster of these?
Space travel is so incredibly expensive.
Rather than spending the big $$$ on going into space now, they should be spent on finding more efficient means of space travel.
They should be researching propulsion systems, building waystations in orbit, building lunar refueling and repair facilities, gas^H^H^Hwater stations for fusion reactors etc.
In 100 years, when we have a reasonable handle on these things, we can begin sending probes into deep space, taking holiday trips to Mars and much much more, and we will learn infinitely more than we would learn from a Pluto mission today. To attempt these things before we have developed decent space travel logistics, is just a waste of resources.
OK, so you and I will not live to see the the results of such a long term plan. But then space exploration is inherently long term.
/A
And what are we looking for on Pluto again?
Put a server farm out there, use heavy encryption, et violá! instant data haven. Let the FBI try to seize that! Of course, a half-day transaction latency could be a problem, but faster than lightspeed communication is just around the corner, right?
c'mon people! let's take risks....we need to start sending manned missions to places like Mars and Pluto.
;-)
i got an idea on how we can fix the problem of overcrowded prisons
mitnick in space: coming to theatres this fall.
FluX
After 16 years, MTV has finally completed its deevolution into the shiny things network
"It is seldom that liberty of any kind is lost all at once." -David Hume
This story says that Pluto might have once been bigger than it is now. They say that perhaps the old Pluto had a collision with something else, causing Charon, (much like the theories of our own moon's formation, probably most big moons are made this way) the Kuiper belt, and the odd orbit Pluto has now. Maybe Pluto did cause the eccentricity of Neptune's orbit, it just did it when it was bigger.
No, it's not.
RTG Plutonium is Pu-238, with a much shorter 89 year halflife (Pu-239's is 24,000 years). Pu-238 is generally considered not fissile. Other isotopes used have included Ce-144, Cm-242, Sr-90, Po-210; Pu-238 has the longest lifetime of those and that led to its being the standard for all RTGs flown by the US since 1964, though some other experimental units with other isotopes were tested in the 60s and 70s.
Heat output is roughly inversely porportional to halflife (how much of it decays in a given time period?).
Pu-238 is produced by irradiating Np-237 and chemically extracting the Pu-238. I don't know what the process is for creating the Np-237. The problem with spent commercial reactor fuel is separating the desired material from all of the other elements and isotopes. Special "low burn-up" reactors are used to produce Pu-239 from uranium. A commercial reactor produces plutonium with a high percentage of short-lived plutonium isotopes, which is undesirable for use in nuclear weapons. Chemical separation extracts all of the plutonium, not just the desired isotope. For RTGs, you only want the Pu-238.
Mea navis aericumbens anguillis abundat
And what are we looking for on Pluto again?
Exactly what we've been looking for on all the other planets. Some sort of Amazon society. Standard operating procedure is that we send a team of astronauts (they must have names like "Duke" or "Buzz") onto the planet. They are captured by the warlike Amazons. While imprisoned, the Amazon leader's daughter falls in love with Duke (or Buzz), helps them escape, and they take off in their rocket back to earth.
I hereby volunteer for the mission.
And I'm changing my name to Duke (or Buzz).
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Ever since stuff stopped being free.
Nobody is saying that stuff shouldn't be explored. It's just that there's a finite amount of resources. Wouldn't it suck if we went ahead and sent something to Pluto, at the expense of not having enough money for, say, a Europa mission? There's a lot of interesting things to look at, Pluto is only one of them.
Unless you have a solution to the age-old economic problem of scarce resources, there's always going to be someone who looks at the nebulous expected returns of a mission and wonders why he should give up _____ for it.
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As copyright owner of this comment, I authorize everyone to defeat any technological measure which limits access to it.
Yep, there was a supply of plutonium that could have solved the RTG problem. When the Russians dismantled missiles to comply with START, they saved the plutonium as a national resource.
And we just paid the Russians to dispose of it.
Oh, well. Who needs space exploration when there are proven-ineffecive programs like Head Start and DARE on which we can piss away money...
(Head Start has been shown to have no effect on the student's future high-school grades, graduation rates, college admissions, standardized test scores, dropout rates, or any other measure of academic achievement. DARE has been shown to have no effect on drug use.)
Steven E. Ehrbar
This isn't Pu-239, the isotope that is used in nuclear weapons. We have huge amounts of Pu-239. Radioisotope Thermoelectric Generators (RTG) use Pu-238, a plutonium isotope with a much shorter half-life (87.7 years). The problem is producing the material. Pu-238 was produced by the Department of Energy as a byproduct of the nuclear weapons materials production infrastructure, which has largely been shut down. There has been discussion of restarting a capability to produce Pu-238, but I'm not sure if any progress has been made. There are plenty of anti-nuclear know-nothings who are opposed to the idea.
Mea navis aericumbens anguillis abundat
Many people here seem to think this kind of missions are quite useless and especially to the Pluto; the small, frozen planetary body far far away.
In my opinion it is one of the most interesting planets in the solar system. We know almost nothing about it. Anyway, the facts we know about of it's size, mass and possible compounds it consists of, are really interesting. Like already said here, the planet is believed to have an atmosphere which is now in a gaseous state because the planet is close enough to the sun (it has a weird, a bit like asteroid or comet style orbit but it's much bigger than any of them). When the planet moves on, it also get's more far away from the sun and the atmosphere is going get frozen. Or to put it the other way, it's gonna lose it's atmosphere for some 200 years.
The mission doesn't have so much time.. The probe should be sent now or really soon to get to the planet in time when there is still an atmosphere.
As a conclusion, I think the planet is WEIRD and that makes it a perfect and an interesting case of study from which we could learn something (at least scientifically).
In addition, the probe would not be there to only study Pluto, but also general conditions in that part of the Solar System - the Kuiper disk. It would also study some astoroid bodies there etc... We don't know almost anything about the Kuiper disk either.
- "I've gone beyond the truth - it's just another lie"
Pluto/Kuiper Express (PKE) was to be one of three JPL solar system exploration missions. The other two include Europa Orbiter (intended to determine the existance of a subsurface ocean), and Solar Probe (intended to determine the origin of the solar wind). PKE's purpose was to image Pluto and Charon (Pluto's moon) and a Kuiper Belt object. EO's biggest challenge is it's complex orbit insertion. SP, of course, has to deal with an intense thermal environment.
PKE's principle challenge was to reliably conduct an autonomous encounter navigation after spending 8 years travelling out there. The craft would be zipping past Pluto at a good clip, and clicking a few pictures (for later transfer back to earth) would be tricky - gotta have the camera pointed in just the right directions at just the right time.
The reason autonomy is necessary, is that at Pluto, the round-trip time for a beam of light to travel between Pluto and ground control is 8 hours, but the entire Pluto encounter only lasts a few hours.
Another problem, mentioned in the article, is that finding a launch vehicle with sufficient performance to get enough mass (a few hundred kg's) going on an accurate trajectory, is pretty tricky.
I think it'd be a pretty cool mission, although I can understand why NASA may prefer to direct their funds towards other projects that would return larger amounts of results for less risk. I hope this doesn't mean Europa Orbiter or Solar Probe are also in danger of cancellation.
There are three ways to dissipate heat, radiation, conduction and convection. In a vacuum, your choice is limited to radiation. You radiate the excess heat into space. There is some tricky engineering involved in keeping the different parts of a spacecraft within a reasonable temperature range.
Mea navis aericumbens anguillis abundat
Uhhhh... interesting statement, but I have to disagree. When Clyde Tombaugh discovered Pluto on February 18, 1930, he was searching for a ninth planet predicted to exist because of discrepancies between the predicted and actual orbits of Uranus (and Neptune) -- the precise reason that the planet Neptune had been discovered, in fact (here's a detailed story of the whole affair). At the time, no one had any notion that Pluto would be so small: it was predicted to be between two and seven times the mass of Earth, and everyone expected it to be dim -- why else would it be so hard to find?
As it turned out, the most likely cause for Uranus and Neptune's orbital discrepancies is probably observational error, and Pluto just happened to be in the approximate neighborhood being searched. If it were discovered today, we might not call it a "planet" -- it's only the largest (so far) of a number of objects in the Kuiper belt -- but this has been the subject of a lot of controversy, and it's been officially decided to keep calling it a planet.
At the time it was discovered, no one had any notion that things would turn out this way, so it was just considered a planet and named as such. No special considerations or rewards -- just ignorance of the future, as always...
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Politics is about making compromises. Religion isn't. --Michael Horton
Ganymede is larger than Mercury, yet it is still considered a moon.
The issues surrounding PKE have mostly to do with large budget squeezes within NASA, with the long flight time, and with the radiothermal generator stuff. No need to spout about the reasons why the budget is tight -- though astute people will recall that there's some sort of orbital treehouse that's a leetle bit over budget. It's also hard to justify now spending a bunch of money that can't conceivably pay off until after the next president's term is over -- the flight time to Pluto is >8.5 years. (That sounds like a long time, until you realize it's taken over 12 years just to get the project from NASA HQ outside the Capitol Beltway.) Other folks have pointed out that, due to the unexpected outbreak of world peace, there's comparatively little nuclear weapons development going on -- and hence not much Pu-238 to be had. Further, all the reactionaries who tried to prevent the Cassini launch (did any of them actually bother to calculate the worst-case release scenarios?) are still around, and now they're mad as Hell. The protests and legal action tripled the cost of the RTGs in Cassini, and PKE will have similar problems.
Solar Probe will have trouble with Pu as well, but at least that mission has an alternative. Solar panels, oddly enough, won't work -- they'd get too hot to work around Mercury's orbit, and melt a few days after that. The current plan has a couple of different solar flybys happening -- that requires RTGs, which will last long enough to do the job. But NASA could back off to a single-flyby mission. Then a jettisonable set of solar panels would be used during cruise phase. During the flyby, power would be supplied by a bank of chemical batteries. But then the probe would be dead, dead, dead shortly after the last data from the flyby were downlinked to Earth.
Both of these spacecraft concepts would require incredible miniaturization. Our proposal (I helped write one submitted by Southwest Research Institute) has instruments that are about the size and mass of full beer cans.
Thats not true, at least the part of Jupiter's gravity. Compared to the Sun Jupiter isn't shit. The AB is the point where the dense heavy materials in the early Solar System's accretian disk started to thin out to such an extent they could not form a planet. There is plenty of space between Jupiter and Mars to fit a planet the problem is the lack of dense material in the inner Solar System.
I'm a loner Dottie, a Rebel.
Pluto is asking to be explored merely as a scientific and technological challenge. There is still plenty to learn from our Solar System. I'd like to see close up pictures of Pluto in my kids' text books someday. There are all of the aguments about pure science exploration because it "wastes" money and doesn't return much of empirical value. If I seem to remember correctly, before the Apollo program computers inhabited a very large room and sucked a great deal of power. Amazingly NASA ended up being able to fit a self contained computer into the Apollo spacecraft to aid the Astronauts in their navigation. Finding faster and cheaper ways of launching scientific flights also solves the problem commercial flights have, the transit from the surface of the Earth into orbit. You don't seem to mind using the technology researched by NASA when you watch satillite TV or make an international telephone call. I've also seen people comment about wasting money going to Mars (and Pluto) when children in various places are starving. Why not dismantle militaries to feed people rather than worry about peaceful programs, or better yet sell your SUV and feed them yourself.
I'm a loner Dottie, a Rebel.
Interestingly enough, the orbit of the Moon is smoothly convex relative to the Sun -- it's orbital period around Earth is long enough that there aren't any cusps in its orbit, as there are in so many other moons. So in a sense it could be considered to orbit the Sun in gravitational association with Earth, and there have been numerous suggestions that the Earth/Moon pair should be considered a double planet rather than a planet/moon.
But there's that history thing again, so I think the nomenclature won't change...
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Politics is about making compromises. Religion isn't. --Michael Horton
What do you mean by "more efficient" ways of space travel? Let's investigate your ideas one by one : (a) Research New Propulsion systems : And to go where? Propulsion systems technology is driven by need, and if you don't plan to go anywhere, there is no need. So no new systems. (b) Building Waystations in Orbit : This is one of those "myth" ideas that perpertuated by too much science fiction. Waystations in orbit are stupid : you waste fuel getting into an orbit instead of just flying straight to your target. Now, you say (ala Armageddon), we can "refuel" there. But then how the hell does the fuel gets there in the first place? Answer : you fly them there, and that takes MORE fuel. It's easy to show (mathematically) that costs more (basically, rockets scale up favourably : the bigger they are, the cheaper they get per kg payload). So go do some maths. (c) Building Lunar Refueling station : That's another science fiction myth. Do you know it's CHEAPER (i.e. smaller rocket) to land something on Mars than to land something on the Moon? Crazy? No : mars has an atmosphere to aerobreak a probe. Moon does not. I know : I spent a month doing calculations in a feasability study on a "Cheap Lunar Lander" mission. Going to the Moon to refuel is like going to New York to refuel on a trip from Chicago to Los Angeles. (d) Repair Facilities : In space, you don't "repair" something : you replace them. It's WAAY cheaper to be redundant in components than to build elaborate facilities to repair things....without knowing what things/spare parts/equipment to stock because you don't know what's going to fail. (e)Water stations for Fusion Reactors : Water has H and O inside, and H2O2 (Hydrogen Peroxide) is standard rocket fuel. But you need FISSION reactors to get H and O out, NOT Fusion Reactors. And you don't need Water Stations : you need water extractors : and they already exist. My professor once told me that people who think that they can "plan everything ahead", and do all the groundwork before pushing the "magic button" and elaborate things will happen is going never going to be successful. Because research is a trial and error procedure. So There!
Mode (3) smart-aleck mode. Press * to return to main menu.
That type of statement is the reason NASA's budget has been cut so drasticly over the years, which directly led to the high-profile failures of some of the recent Mars missions. We're not looking for anything in particular; the whole point of a mission such as this one would be pure exploration - we don't really know what to look for, so you have to begin somewhere. It's true that there will never be (in our lifetime, at least) any commercial value from the exploration of Pluto, but does that mean we shouldn't go there? If that kind of test were applied to all matters of exploration and research, we'd still be in the dark ages.
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http://gammatron.weblogger.com
You're kidding, right?
/., Timothy.
How about solving the question of whether it formed here or was captured? And, if the latter, learning about how planets form around other suns.
If you don't understand what we're looking for on Pluto, you shouldn't be editing Science stories on
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What's with all this crap about being soooo cautious about space exploration. Let's just keep sending stuff out there until we succeed in getting to the other planets. I don't care if people die trying - shove the next door neighbours dog in the damn things and see if they get there. Aim my microwave at Mars and launch the sucker. I'm sick of waiting for this so called "space program"... the best way to succeed is to learn from failure.
If the "space program" ran the aviation industry in the first half of this century we wouldn't have aeroplanes, we would be sitting on the tarmack too frightened of flying for fear of killing someone, or losing a buck.
By the time the space program ever gets anywhere, intelligent life will have evolved on another planet and they will have found US.
The same picture says that Ganymede and Titan are larger than Mercury. Does it mean that Mercury is not a planet, or that Ganymede and Titan are planets?
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Pluto reached perihelion (closest point to the Sun) on 1989 September 5 at 12:00 UT. At that time it was at 29.66 AU, or 4.4 billion kilometers, or 2.7 billion miles from the Sun. Pluto became the "eighth" planet on 1979 February 7 at 10:44 UT when it came to a distance from the Sun less than Neptune. It will continue in this status until 1999 February 11 at 11:22 UT when it will once again be further from the Sun than any other planet. Its status as the ninth planet will remain undisputed for the next 220 years when it will once again be approaching perihelion.
Crunch, crunch; chew, chew; crow. Pttui! <g>
We are looking for that which we do not know.
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Okay, that's it. You guys aren't real nerds. Time to change your slogan.
Somehow I suspect that this Plutonium "shortage" has more to do with fear of another political flap, like the one surrounding the launch of the Cassini probe (oh my god, they're launching *Plutonium*... on a rocket!).Science shouldn't always have a direct application or use. It's their because once in a while it creates something amazing, that changes everything and affects everyone. You can't always directly apply science to solve a need. Sometimes you don't know a need was there until it has been satisfied.
I mean we still don't know what (if any) atmosphere exists around pluto. Knowing the material composition would tell us more about where Pluto actually came from, like was it formed at the same time as the rest of the solar system or was it just a BIG comet...
Why do we study any of the planets, why do we look for bones in the ground that are a few million years old? We know Dinosaurs exitst, I guess for some people that's enough infomation.
Bye the way here is the link to the actual Space.com story. What really intersts me is not really Pluto per se, but exploring around in the Kuiper Belt, where most of the comets are thought to be from, and just getting useful information from just beyond our solar system.
"People of Earth. Welcome. .. or was it miles?.
Please come to our planet.
We are only 5,913,520,000 mil^H^H kilometers from the sun.
er ummm
Nevermind."