StyroCupMan writes "NASA has announced that it will launch a satellite to map our solar system's boundary. It will also study the particles and radiation that pose a health and safety hazard to humans. Time to invest in that shiny new spacesuit."
What about the galactic boundary?
by
daeley
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· Score: 2, Interesting
Reminds me of that Star Trek TOS episode -- the first after the pilot if I recall correctly -- where they "break through" the "galactic boundary," thus triggering god-like powers (and accompanying morality tale) in a couple of crew members.
You also get to see the phaser rifle for one of the few times ever in that episode.:)
-- I watched C-beams glitter in the dark near the Tannhauser gate.
The birth of interstellar exploration
by
It+doesn't+come+easy
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· Score: 3, Interesting
Pretty cool. We are about to transition into the age of interstellar exploration, at least technically speaking, once the Voyager 1 probe "officially" cross into interstellar space. The actual boundary shifts in relation to the activity of the sun and so this new satellite should help determine (among other things) when Voyager has crossed over.
Interesting note: The Pioneer/Voyager probes illustrate the space exploration concept that the later you leave, the sooner you get there...
-- The NSA: The only part of the US government that actually listens.
Re:The birth of interstellar exploration
by
Thing+1
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· Score: 2, Interesting
I remember a short story (no idea where or who; probably an old Analog or Asimov's Sci-Fi Magazine) in which a "life-boat" had left Earth, and about halfway to Alpha Centauri they were awoken by a klaxon and saw a flash.
Then they went back to sleep.
When they finally got there (only 4 light years away), they came upon a civilization of humans thousands of years advanced beyond ours, and the worst part was that the travelers stank like pigs (apparently the olfactory sense and sweat glands had evolved in the humans who "passed" them).
Neat story, and completely fits with "he who leaves last, arrives first."
-- I feel fantastic, and I'm still alive.
Historically speaking...
by
anactofgod
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· Score: 3, Insightful
This "surveying" of boundaries by my government has traditionally been the first step in the staking of claims and the erection of fences and walls. When does the landgrab start? I want to plan my flag on a choice piece of real-estate. *g*
So, I have a question. Why is it that when scientists talk about exploring the edges of the solar system, they insist in sending probes "out past Pluto"? On the one hand, I understand why we do so - our solar system does lie (primarily) in a plane, so it's natural to think that way.
But I argue it'd be easier to explore phenomina at the edges of our solar system by going in the third dimension - orthogonal to the plane of the solar system. After all, the Sun isn't just radiating in a 2-d plane. Or am I wrong in my assumption about how solar winds radiate?
Any scientifically sound reason why this is a bad idea?
Or are we doomed to continue think as Khan did/does/will? *grynn*
--
---anactofgod---
"Equal opportunity swindling - *that* is the true test of a sustainable democracy."
Re:Historically speaking...
by
iainl
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· Score: 4, Interesting
The problem, if memory serves, is that it's a lot easier to sling a probe out along the plane than it is to send it "up or down" with any speed - simply because it's being launched from Earth any probe will already have a substantial amount of momentum in the plane.
-- "I Know You Are But What Am I?"
Re:Historically speaking...
by
StyroCupMan
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· Score: 2, Informative
That is a very good question. There a couple reasons I can think of as to why exploration is primarily in the same plane as the planets.
First, you can get there faster by using the gravity of intervening planets.
Second, you can do some interesting science (take pictures, etc) on the planets and other objects you pass by.
-- If I may say so, life is a game, and there's so much to do and so few turns. -Reiner Knizia
Re:Historically speaking...
by
CrimsonAvenger
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· Score: 4, Informative
Any scientifically sound reason why this is a bad idea?
DeltaV required to head out perpendicular to the plane of the ecliptic is quite a bit higher than to go out along the ecliptic.
Achieving Solar escape speed from LEO in the plane of the ecliptic is ~9Km/s.
Perpendicular to the ecliptic, deltaV required is ~26Km/s.
And it's tough to use planetary slingshots when you're going out perpendicular to the ecliptic.
--
"I do not agree with what you say, but I will defend to the death your right to say it"
Re:Historically speaking...
by
jnik
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· Score: 2, Interesting
Why is it that when scientists talk about exploring the edges of the solar system, they insist in sending probes "out past Pluto"?
Your question has been answered by others here, but I should point out that this particular mission is exploring the edges of the Solar system from Earth orbit. Hardly out past Pluto:)
(article doesn't specifically say that, but implied from the budget, the program it's under, and the fact that it's observing ENA's...remote sensing using ENA's is one of the Cool Things right now).
Re:Historically speaking...
by
escher
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· Score: 2, Informative
i never understood this. why do you have to go 9km/s to escape the Earth's gravity?
if you can move upwards at an inch a day, eventually you would leave gravitational pull, woudln't you? why is the 9km/s significant?
The 9km/s is significant if you only have the launch velocity to work with (like throwing a rock).
The inch per day example only works if you're constantly accellerating (say, via a rocket).
9 km/s is the static speed you must be moving if you stop applying thrust. In other words, when you stop applying thrust, you'd better be going 9 km/s or faster or the Earth will eventually pull you back.
Your example of moving up 1 inch per day (do you work for NASA, mixing measurement systems like that, now really!) implies that you continue to accellerate enough to maintain your position (i.e. you do not allow yourself to fall back that one inch) until you move up further.
-- The NSA: The only part of the US government that actually listens.
Re:Historically speaking...
by
mopomi
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· Score: 4, Informative
Basically, an object needs a specific amount of energy to escape the gravitational well of some other object. Remember that kinetic energy is KE = 1/2 mv^2,
where m is mass and v is velocity.
Gravitational binding energy is the energy required to escape a gravity well (basically):
GE = GmM/R,
where G is the gravitational constant, m is the mass of the escaping object, M is the mass of the planet, and R is the planet's radius.
Setting KE=GE and solving for velocity gives you the escape velocity (the very minimum INITIAL velocity required to escape with NO ADDITIONAL ACCELERATION). Notice that the object's mass cancels, so you're left with a constant value for the planet's escape velocity (of course, you need more energy to accelerate a more massive object to the same velocity). Earth's escape velocity is actually 11.1 km/s. Not sure where that 9 km/s comes from.
Re:Historically speaking...
by
Anonymous Coward
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· Score: 2, Informative
Two reasons why these probes have been sent out along the orbital plane (at least initially):
1) Much of the speed is generated by the slingshot effect from a planet. The Voyagers used this effect at each planet to gain the necessary speed to reach the next- they did not attain enough speed to escape the solar system until after the third or fourth planet.
2) These probes are EXPENSIVE. If we want to launch one out of the solar system, why not along the direction where we can make planetary observations along the way? The Pioneer and Voyager probes were primarily meant as planetary probes; observations of the edge of the solar system were only a secondary intent.
BUT.... There is no reason why the last planetary slingshot can't be used to throw the probes off into a non-solar system plane- this is exactly what they have done. The Voyager probes are no longer in the plane of the planetary orbit; I believe both of them are now travelling in a direction more than 30 degrees from this plane.
Re:Historically speaking...
by
CrimsonAvenger
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· Score: 4, Insightful
Earth's escape velocity is actually 11.1 km/s. Not sure where that 9 km/s comes from.
Read carefully. That was deltaV required to go from LEO (Low Earth Orbit) to Solar escape speed.
It assumes a starting speed of ~8Km/s (Actually, the orbit I assumed had ~7650m/s orbital speed), and a single burn in the direction of both the orbit around the Earth and the Earth's orbit around the Sun. It further assumed Solar escape speed was 42.1Km/s, which is true for a couple points along Earth's orbit, but I'm not sure exactly where, so I won't tell you the dates required for the burn.
If you add 9Km/s to your speed under those conditions, then you will find yourself moving along smartly in the plane of the ecliptic at just over 5250m/s relative to the Sun at some point in the indefinite future, when you are some arbitrarily large distance from the Sun (on the order of two light-months out, give or take a couple light-weeks)
--
"I do not agree with what you say, but I will defend to the death your right to say it"
Re:Historically speaking...
by
Graymalkin
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· Score: 2, Informative
I don't think you really understand the need for gravitational assists. Without such assists a probe using current launch technology would not be able to make it anywhere close to the edge of the solar system. We can't just fire these things off in a roughly straight line. They're launched in what are essentially variations of a Hohmanntransfer orbit. Instead of moving from one circular orbit to another though, you're transfering from a circular orbit to a hyperbolic one. The same concept applies, energy needs to be added to increase the altitude of the orbit which is where the gravity assist comes in.
Shooting a probe off perpendicular to the mean plane of the solar system would be shooting yourself in the foot. You'd be entirely missing out on the enormous gravitation boost Jupiter and/or Saturn offer. You would need überamounts of extraordinarily energetic fuel to make the trip without using the gas giants. Even then the rocket (as mentioned) would need to be about 98% fuel. We can at best build ones that are 90% fuel.
There's also a shitload of vaccuum in the planetary plane just as there is perpendicular to the plane. There would really be little use in avoiding the planetary plane as you suggest. Besides the boost the probe would get from the gas giant(s) it could be put on a course where some secondary science could be conducted on the way to the edge of the solar system. You wouldn't need extra equipment to study doppler shifts as the probe entered say Jupiter's gravity well during an assist or watch it's radio signal as it was occulted by the planet for frequency varations to infer magnetic fields or ionized particles in the atmosphere.
-- I'm a loner Dottie, a Rebel.
Understanding our environment
by
helioquake
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· Score: 2, Insightful
A fascinating mission.
Every scientific study indicates that the Big Bang had generated light atomic elements (Hydrogen and Helium, etc). But other heavier elements -- the founding block of life and everything we live in -- have been synthesized by stars. We have a pretty good model in nucleosynthesis, really. But little we know HOW these heavier elements are re-distributed throughout interstellar space. This mission will touch upon that topic by exploring the condition where the Sun's wind interacts with the primodial (?) material that surrounds the Solar system.
Cool, indeed. And the principle institute is located in San Antonio, TX. Even if they go over budget, it's gonna be easy to impress the congress or the White House to allocate more money...well, I'm quasi-kidding about that!
Why do we need this? Someone please explain it to me. None of the Pioneer or Voyager probes have yet to reach the heliopause and they were launched in the 1970s. So we should expect to see results in sixty years? How about doing some USEFUL exploring like investigating Pluto/Charon and KBOs?
-- "Well Ranger Brad, I'm a scientist. I don't believe in anything." - Dr. Roger Fleming
Re:Why?
by
Anonymous Coward
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· Score: 2, Informative
If you read the article this is part of the Small Explorer Mission so this probe has a very limited set of instruments and a narrow focus of inquiry, so it is relatively inexpensive. Note the estimated price, $124 million, a few orders of magnitude cheaper than the Gaileo probe, and you would want a probe with that range of capabilities to go to Pluto.
I do agree that a mission to Pluto would be great, especially before it progresses to the part of its orbit where its atmosphere freezes. However, this is like complaining you can't afford to buy a car because your significant other bought a skateboard.
That very same mentallity is what doomes many, many projects. Things which are similar can, in some cases, be wrapped together for savings. However, just saying "it's a space probe so these tasks are similar" is not valid
If you want to build a probe to explore the heliosphere, that's great. If you want to study other planets, that's great too. But do that in another project. In this case, reaching the heliosphere requires energy and fuel. Bolting on instruments and crap to study things on the way out increases flight path complexity, time till results, and weight. This hinders the probes ability to get out to the heliosphere (prime objective) in the first place.
When you make a tool for a job, that tool/project/task needs to fit the order. When you start bolting on other crap, it becomes big, bloated, error prone, and typically comprimises the initial mission.
-- -
Sig
Re:Why?
by
Anonymous Coward
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· Score: 2, Insightful
How in the world is this useless? Everytime there are plans on exploration in space, or someone announce a new discovery in the lab, someone says "so what? what's the point?" I suppose it's futile to explain the point of science, to someone who refuses to see a point at all.
The article merely says that IBEX is to be placed in a highly elliptical orbit around the Sun, but offers no quantitative details. How far out is it meant to go? If beyond Pluto at 40 AU, its average distance to the Sun will be at least 20 AU, resulting in an orbital period of around 90 years (much like comet Halley with 76 years). I think that's a long-term science commitment. The Pioneer and Voyager probes were able to get out there faster because they are on non-return trajectories (hyperbolic, I suppose).
Do they plan to defy Kepler's laws and speed up the trip by using either gravity assist from the major planets or onboard propulsion? In either case, I wouldn't call the resulting trajectory an "orbit" in itself, but quite substantial deviations from one. Will the IBEX probe survive long enough to cross the heliopause more than once?
Re:Long-term science
by
jnik
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· Score: 4, Informative
Nobody said the probe is actually crossing the termination shock. It's observing ENA's generated at the termination shock.
Uber-brief introduction to energetic neutral atoms: Ions (charged particles) are susceptible to magnetic and electric forces. As a result, they can be boosted to very high energies in certain situations, but also usually can't travel very far before being modified in some way by electromagnetic forces. If, however, an ion interacts with a neutral (charge exchange), it can "steal" one or more electrons from the neutral without substantially changing the energies of either, leaving a nonenergetic ion and an energetic neutral, which then leaves the vicinity as it is no longer subject to EM forces. We can observe these ENA's and infer properties of the acceleration region.
How much will this cost?
by
VoxVeritas
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· Score: 4, Insightful
I think this is a good idea. I just wish that they would save Hubble. They way they are dealing with Hubble is like junking your car just because it needs a new battery.
Hmmm... my girlfriend tried that logic too...
Better maps of the solar system needed
by
Anonymous Coward
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· Score: 2, Interesting
I'd much rather see them put some resources into mapping out the solar system. They should start producing some mini-probes with just enough power onboard to run a RADAR dish and a small telecommunications router for a couple of decades. Launch a couple of these every year and let them start to discover many of the smaller bodies scattered throught the solar system. They could also begin service as an interplanetary communications network. If the RADAR dish consumes too much power, then just give them very sensitive, omni-directional antennea and let them listen for reflected transmissions.
Anyway, it's just a thought.
Re:Better maps of the solar system needed
by
hcdejong
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· Score: 2, Insightful
A radar isn't a low-power device, especially at the range you'll need (calculating the volume you'll have to scan is left as an excercise to the reader). Simple navigation/weather radars (range: 200 km) require hundreds of W. An omnidirectional antenna doesn't give you information on the direction of the signals (which you need), and relying on 'reflected transmissions'? How would you differentiate between reflections and sources?
Re:Leaving the ecliptical plane
by
CrimsonAvenger
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· Score: 2, Informative
Arhtur C CLarke was a great man, he really was.
But he was wrong here. If you're in a polar orbit to start with, you'll need a bit more deltaV than I described, since I assumed the ideal departure orbit (one where the burn was entirely in the direction of travel).
The big difficulty with going into a Solar polar orbit is that you have to cancel Earth's orbital speed as part of the orbital insertion burn. And Earth's orbital speed is ~30Km/s, more in northern-hemisphere winter, less in northern-hemisphere summer.
That ion drive that was tested this past year could, conceivably, be used to come up with the deltaV required for a Solar-polar orbit that was also a Solar-escape orbit. But no chemical rocket we can make can pull it off.
--
"I do not agree with what you say, but I will defend to the death your right to say it"
You don't exactly, but it's the only sensible way
by
Julian+Morrison
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· Score: 3, Insightful
Escape velocity is for a ballistic trajectory. Ballistic, meaning unpowered after the launch. That is, if you chuck a rock at sea level upwards at that speed, it will slow and slow but never quite stop.
What you're talking about is escaping by just continually going upward, like climbing a ladder. Which you could, if there were a big enough ladder - but of course there isn't. So rather than standing on a solid, you have to continuously accelerate against gravity to even stay put. Possible - it's what a Harrier jump jet does when hovering at take-off - but expensive in fuel, meaning you can't do it long enough to get anywhere useful before the fuel runs out. It makes more sense to burn all your fuel as early as possible, accelerate as fast as possible, and coast most of the way ballistically. That way you get rid of the fuel fast (it's heavy and expensive to lug) and you don't waste effort just staying put.
There are so many other interesting ideas out there. Why spend tens(hundreds) of millions on a mapping of the so-called interstellar boundary. Besides, it's not like they're going to the Oort Cloud. Why not revisit Venus, send a probe to Io, plug that money into Pluto Express. I can't see how anyone can be too enthusiastic about this mission. lilmac558@gmail.com
Wait a minite guys..
by
adeyadey
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· Score: 2, Informative
IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere.
Guys, I know the article says very little, but from what I can see this probe orbits the EARTH, not the sun, in an elliptical orbit, with sensors to examine (amongst other things) particles from the heliopause. Makes sense - $134 million would not be nearly enough money for a deep-space mission - the Plutonium nuclear batteries (RTG) alone would cost most of that. Deep space needs expensive support from Deep Space Network, and advanced/expensive comms. To get to Earth-escape you need an expensive big rocket too, unless you use ion. This probe will probably run off solar.
To get an idea of what even a "cheap" mission to Pluto & Heliopause is going to cost see the New Horzons page http://pluto.jhuapl.edu/ - this will be around $600 million. Apparantly they are in a real race against time to make the Jan 2006 launch window - there was a hitch at Los Alamos where they make the RTGs - Plutonium 238 is currently very hard to get hold of & they might not have enough by launch date. Shame they are not funding a "cheap" copycat 2007-8 NH-2 mission which could swing by Jupiter,Uranus & a few more KBOs including a nice double system..
By the way I do think it could be done cheaper still - when are we going to have a true deep space ion craft? (solar+RTG)
Slashdot Mirror
Reminds me of that Star Trek TOS episode -- the first after the pilot if I recall correctly -- where they "break through" the "galactic boundary," thus triggering god-like powers (and accompanying morality tale) in a couple of crew members.
:)
You also get to see the phaser rifle for one of the few times ever in that episode.
I watched C-beams glitter in the dark near the Tannhauser gate.
Interesting note: The Pioneer/Voyager probes illustrate the space exploration concept that the later you leave, the sooner you get there...
The NSA: The only part of the US government that actually listens.
This "surveying" of boundaries by my government has traditionally been the first step in the staking of claims and the erection of fences and walls. When does the landgrab start? I want to plan my flag on a choice piece of real-estate. *g*
So, I have a question. Why is it that when scientists talk about exploring the edges of the solar system, they insist in sending probes "out past Pluto"? On the one hand, I understand why we do so - our solar system does lie (primarily) in a plane, so it's natural to think that way.
But I argue it'd be easier to explore phenomina at the edges of our solar system by going in the third dimension - orthogonal to the plane of the solar system. After all, the Sun isn't just radiating in a 2-d plane. Or am I wrong in my assumption about how solar winds radiate?
Any scientifically sound reason why this is a bad idea?
Or are we doomed to continue think as Khan did/does/will? *grynn*
---anactofgod---
"Equal opportunity swindling - *that* is the true test of a sustainable democracy."
A fascinating mission.
Every scientific study indicates that the Big Bang had generated light atomic elements (Hydrogen and Helium, etc). But other heavier elements -- the founding block of life and everything we live in -- have been synthesized by stars. We have a pretty good model in nucleosynthesis, really. But little we know HOW these heavier elements are re-distributed throughout interstellar space. This mission will touch upon that topic by exploring the condition where the Sun's wind interacts with the primodial (?) material that surrounds the Solar system.
Cool, indeed. And the principle institute is located in San Antonio, TX. Even if they go over budget, it's gonna be easy to impress the congress or the White House to allocate more money...well, I'm quasi-kidding about that!
Why do we need this? Someone please explain it to me. None of the Pioneer or Voyager probes have yet to reach the heliopause and they were launched in the 1970s. So we should expect to see results in sixty years? How about doing some USEFUL exploring like investigating Pluto/Charon and KBOs?
"Well Ranger Brad, I'm a scientist. I don't believe in anything." - Dr. Roger Fleming
The article merely says that IBEX is to be placed in a highly elliptical orbit around the Sun, but offers no quantitative details. How far out is it meant to go? If beyond Pluto at 40 AU, its average distance to the Sun will be at least 20 AU, resulting in an orbital period of around 90 years (much like comet Halley with 76 years). I think that's a long-term science commitment. The Pioneer and Voyager probes were able to get out there faster because they are on non-return trajectories (hyperbolic, I suppose).
Do they plan to defy Kepler's laws and speed up the trip by using either gravity assist from the major planets or onboard propulsion? In either case, I wouldn't call the resulting trajectory an "orbit" in itself, but quite substantial deviations from one. Will the IBEX probe survive long enough to cross the heliopause more than once?
I think this is a good idea. I just wish that they would save Hubble. They way they are dealing with Hubble is like junking your car just because it needs a new battery.
Hmmm... my girlfriend tried that logic too...
I'd much rather see them put some resources into mapping out the solar system. They should start producing some mini-probes with just enough power onboard to run a RADAR dish and a small telecommunications router for a couple of decades. Launch a couple of these every year and let them start to discover many of the smaller bodies scattered throught the solar system. They could also begin service as an interplanetary communications network. If the RADAR dish consumes too much power, then just give them very sensitive, omni-directional antennea and let them listen for reflected transmissions.
Anyway, it's just a thought.
But he was wrong here. If you're in a polar orbit to start with, you'll need a bit more deltaV than I described, since I assumed the ideal departure orbit (one where the burn was entirely in the direction of travel).
The big difficulty with going into a Solar polar orbit is that you have to cancel Earth's orbital speed as part of the orbital insertion burn. And Earth's orbital speed is ~30Km/s, more in northern-hemisphere winter, less in northern-hemisphere summer.
That ion drive that was tested this past year could, conceivably, be used to come up with the deltaV required for a Solar-polar orbit that was also a Solar-escape orbit. But no chemical rocket we can make can pull it off.
"I do not agree with what you say, but I will defend to the death your right to say it"
Escape velocity is for a ballistic trajectory. Ballistic, meaning unpowered after the launch. That is, if you chuck a rock at sea level upwards at that speed, it will slow and slow but never quite stop.
What you're talking about is escaping by just continually going upward, like climbing a ladder. Which you could, if there were a big enough ladder - but of course there isn't. So rather than standing on a solid, you have to continuously accelerate against gravity to even stay put. Possible - it's what a Harrier jump jet does when hovering at take-off - but expensive in fuel, meaning you can't do it long enough to get anywhere useful before the fuel runs out. It makes more sense to burn all your fuel as early as possible, accelerate as fast as possible, and coast most of the way ballistically. That way you get rid of the fuel fast (it's heavy and expensive to lug) and you don't waste effort just staying put.
There are so many other interesting ideas out there. Why spend tens(hundreds) of millions on a mapping of the so-called interstellar boundary. Besides, it's not like they're going to the Oort Cloud. Why not revisit Venus, send a probe to Io, plug that money into Pluto Express. I can't see how anyone can be too enthusiastic about this mission. lilmac558@gmail.com
Startrek.com summary
IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere.
Guys, I know the article says very little, but from what I can see this probe orbits the EARTH, not the sun, in an elliptical orbit, with sensors to examine (amongst other things) particles from the heliopause. Makes sense - $134 million would not be nearly enough money for a deep-space mission - the Plutonium nuclear batteries (RTG) alone would cost most of that. Deep space needs expensive support from Deep Space Network, and advanced/expensive comms. To get to Earth-escape you need an expensive big rocket too, unless you use ion. This probe will probably run off solar.
To get an idea of what even a "cheap" mission to Pluto & Heliopause is going to cost see the New Horzons page
http://pluto.jhuapl.edu/ - this will be around $600 million. Apparantly they are in a real race against time to make the Jan 2006 launch window - there was a hitch at Los Alamos where they make the RTGs - Plutonium 238 is currently very hard to get hold of & they might not have enough by launch date. Shame they are not funding a "cheap" copycat 2007-8 NH-2 mission which could swing by Jupiter,Uranus & a few more KBOs including a nice double system..
By the way I do think it could be done cheaper still - when are we going to have a true deep space ion craft? (solar+RTG)
"You lied to me! There is a Swansea!"