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Pluto Probe Launches
Artem S. Tashkinov writes "The US space agency, Nasa, has successfully launched its New Horizons mission to Pluto. The $700m probe will gather information on Pluto and its moons before - it is hoped - pressing on to explore other objects in the outer Solar System. Pluto is the only remaining planet that has never been visited by a spacecraft."
In 2015 we should get some pretty interesting data back.
Around the year 2000 there was a website that was setup by a teenager who wanted to see NASA send a space probe to Pluto. The website was www.plutomission.com, and it helped start an online petition that gained well over 50,000 signatures. It also started a huge upsurge of public support for a Pluto mission, and in the end helped persuade NASA into making a real mission out of it. Amazing what a simple website can do.
Here's a closeup of the latest photo of pluto taken by Hubble.
Religion for nerds. Stuff that really matters
From this CNN article, and my buddy Pete at JHAPL, "The New Horizons spacecraft will be the fastest ever launched, more than 10 times faster than a speeding bullet.". That is faster then superman.
For those not aware, had it been delayed past early Feb, the mission would have taken 4 years longer to reach Pluto, due to missing Jupiter for a gravitational 'slingshot' assist.
Roll on 2015. The best images we have of Pluto now are fuzzy Hubble pics, and I can't wait for this to change.
Any comment from the "OMG! Plutonium powered space probes are evil!" people that were hanging little origami birds on a fence outside the launch site? They seemed certain that launching this craft was going to be a disaster. Damn! Now they're going to have to wait for the next one, since neither Cassini nor this new launch have obliged them by crashing into an old growth redwood grove or a daycare center.
Don't disappoint your bird dog. Go to the range.
How is it news 9 hours later?
Actually, I LIKE the 9-hour window. That's exactly how long this thing has taken to pass the moon. That's really, really fast.
Don't disappoint your bird dog. Go to the range.
Gotta agree with you there. I can't stand people that are ignorant enough to protest anything with the word "nuclear" attached to it. Blind ignorance is all that is. They don't even have the most basic understanding of what they are protetsting. They're simply doing it because some hippy teacher during their education told them that they should.
Lemmings.
"Oh my God. This is terrible. This is the end of my Presidency. I'm fucked."; ~ Donald J. Trump
Here's to New Horizons, indeed!
[Drains glass, turns over on top of bar...]
One wonders if NH might contribute some data to finally solve the Pioneer anomaly.
having dated a Wiccan years ago.
Whew. Talk about your eccentric orbits! Glad to have you back.
Don't disappoint your bird dog. Go to the range.
You have to wonder why, with such a long journey, they didn't try out an ion engine. Sure, it would have cost more, but it would have been able to get there a lot faster. The ion engine has a much higher specific impulse than conventional rockets but are only effective over long range where the engines can be fired continuously. What longer range than Pluto? Plus, include a larger Plutonium core and run several of these.
Sure, it is the fastest probe to escape from the earth, but why not strap on an extra stage and get that baby really cookin!
Now I don't really care what it's powered by and what's on it. But will you and the parent poster apologize if one of these probes do explode on lift off?
I mean it's not like anything NASA does ever goes wrong?
I expect that if it ever does happen you'll either be very quiet, or you'll find someone else to take a cheap shot at.
dnuof eruc rof aixelsid
After hearing how this is a flyby mission and the top speed of this spacecraft, I wondered about the current speed champ, Voyager I. According to some of my back of the envelope calculations based upon New Horizons' estimated top speed after a Jupiter assist and the current position and speed of Voyager I, in 26 years New Horizons will surpass Voyager I as the most distant human made object.
"Me fail English, that's unpossible." --Ralphie
What, exactly would I have to appologize for? the actual radiation exposure would be something like being out in the sun slightly longer than you should without sunscreen. That's not great, but frankly if I was concerned about that, I'd make a point of not living within threat range of the cape.
Get over it.
They are very serious about minimizing the exposure, which is why the teams were deployed, but the actual danger is negligable.
No, I wouldn't "appologize". I have nothing to appologize for, and certainly not to you.
"Oh my God. This is terrible. This is the end of my Presidency. I'm fucked."; ~ Donald J. Trump
Just because you're ignorant of major space exploration events doesn't mean the rest of the world is. Take an occasional read of something like The Space Review. Although there's much debate about the planned manned space architecture there's still plenty going on.
How we know is more important than what we know.
The outer planet?
Reavers!!!
Pfft, yeah, I guess.. I mean, if you consider an average speed of 26,539MPH to be fast. If going from LA to New York in 6 minutes is your idea of fast, then sure, this thing is just whizzing along.
https://www.eff.org/https-everywhere
The only image returned by the probe.
In fact, NASA recently finalized the specifications and issued contracts (to Boeing, among others) for the next generation of orbital work vehicles. NASA has stated explicitly that these vehicles will be the testbeds and prototypes for the Lunar and Martian manned mission programs planned over the next ten years or so.
So not only is everything proceeding as planned, but actual physical artifacts are being built at this very moment in direct support of the Mars program.
Some of us think this is very cool, really neat, etc.
Apparently, others prefer ignorance, if it makes it easier to make cheap political shots.
This is exciting science-type stuff! Give the political asshattery a rest, why don't you?
Any sufficiently well-organized community is indistinguishable from Government.
Of the fifty odd launches of reactors or RTG's - no fewer than nine have resulted in the radioactive material being returned to earth. This article lists eight failures, but misses a ninth. It's not a pretty record - and it's only by luck that major contamination has been avoided.
A lemming in this instance is someone who blindly repeats something without understanding it. Consider the carefully the walls of your house before casting stones.The RTGs in question here are not just Plutonium slugs.
y /northern_fleet/incidents/31772.html
Remember there have been accidents with them in the past.
During the three mission accidents that did occur, the RTGs performed as predicted. The Transit 5-BN-3 mission was aborted because of launch vehicle failure. The RTG burned up on reentry as designed with the plutonium dispersed in the upper atmosphere. The RTG design was changed shortly after that to accommodate intact reentry. The next accident was with the Nimbus-B-1 that was aborted shortly after launch by a range safety destruct. The RTG was recovered, with no release of plutonium, and the heat sources were reused in later missions
The failure of the Apollo 13 mission meant that the Lunar Module reentered the atmosphere carrying an RTG and burnt up over Fiji. The RTG itself survived reentry of the Earth's atmosphere intact, plunging into the Tonga trench in the Pacific Ocean. The US Department of Energy has conducted seawater tests and determined that the graphite casing, which was designed to withstand reentry, is stable and no release of plutonium will occur. Subsequent investigations have found no increase in the natural background radiation in the area.
In order to minimise the risk of the radioactive material being released, the fuel is stored in individual modular units with their own heat shielding. They are surrounded by a layer of iridium metal and encased in high-strength graphite blocks. These two materials are corrosion- and heat-resistant. Surrouding the graphic blocks is an aeroshell, designed to protect the entire assembly against the heat of reentering the earth's atmosphere. The plutonium fuel is also stored in a ceramic form that is heat-resistant, minimising the risk of vaporization and aerosolization. The ceramic is also highly insoluble.
http://en.wikipedia.org/wiki/RTG
http://www.ne.doe.gov/space/space-desc.html
http://www.nuclearspace.com/facts_about_rtg.htm
http://www.bellona.no/en/international/russia/nav
Nice information about RTG powered lighthouses
Luck? That's an insult to the engineers who designed those things, and you should apologise. They are professionals, and the reason there hasn't been an accidental release from a US spacecraft is that they were *designed* to survive these accidents. There's nothing magic here. Something that small can be built far far stronger than the minimum requirements. When you do that, to think you're going to have a major nuclear release from a probe like this one is just a bit like saying a stick of dynamite will crack the Earth in half. If you're claiming that the rules of physics are going to be broken, then it's up to you to prove it.
A lemming in this instance is someone who blindly repeats something without understanding it. Consider the carefully the walls of your house before casting stones.
Well, I guess that shuts me up! Oh wait, it doesn't. My walls obey the laws of physics. Do yours?
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
LEO's hardly a vaccuum. That's why orbits decay. You better darn well believe that fluid properties the sparse atmosphere in LEO is important to engineers.
The speed of sound is a lot more important than just for the rate at which sound propagates. Transsonic speeds are extremely turbulent because you have some parts of the craft getting shocks and others not, leaving the flow very irregular (regionally and temporally). Subsonic, supersonic and hypersonic speeds require different profiles for optimal performance (for example, a plane-shaped subsonic craft has the least resistance if the fuselage continues on straight at the wings. A supersonic or hypersonic craft has the least resistance if the fuselage pinches inwards at the wings in order to keep a constant cross section). Shocks can cause regional stresses (tensile, thermal) on parts of the craft. Etc.
Son, a woman is a lot like a refrigerator. They're six feet tall, 300 pounds... they make ice... umm...
Now, being able to walk around afterwards kind-of puts a limit on things, as did the "returning safely", but just the stopping would have been a piece of cake.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
To enter orbit around a planet you need to be going slowly when you get there, at no more than the orbital speed for the planet. New Horizons will be going at 11 km/s when it flashes by Pluto, snapping pictures like mad, whereas the orbital velocity for Pluto is just over 3 km/s. NH is moving at least 3 times too fast to go into orbit.
If you wanted to go into orbit, you'd have two choices. The first, and most economical, is to launch the spacecraft on an elliptical trajectory that just barely reaches out to Pluto. That gets the spacecraft there with the lowest possible speed relative to Pluto. You still have some braking to do, but it's the least possible. Problem is, the length of such a trajectory is about half the period of Pluto's orbit, i.e. 125 years. Ugh.
If you speed things up by taking a faster trajectory, then you end up with much more braking to do. Then the problem becomes: how do you lose all that speed? If the planet had an atmosphere, and you have good heat shielding, you can do a little aerobraking, which is what's done with Mars. But with an airless world you're stuck with bringing along enough fuel to do almost as much braking as you did accelerating from Earth orbit. So far, that has been very difficult without a very large spacecraft. One plausible hope for improvement is to bring along a real nuclear reactor (instead of just an RTG) which can provide lots of electric power, and then use a high-efficiency ion drive to slow yourself down.
The slingshot technique works because Jupiter is also moving--it's in orbit around the Sun, at about 30,000 mph (48,000 km/hr). When the probe approaches Jupiter from behind, the probe is gravitationally attracted to something (Jupiter) traveling at 30,000 mph, so it speeds up. Relative to Jupiter, you're right, it's a zero-sum game (i.e., the probe does seem to speed up and then slow down again, relative to the planet) but the velocity of concern is the so-called heliocentric velocity, or the velocity relative to the Sun, and that is greatly increased.
Note that there is conservation of energy, of course; Jupiter also slows down in its orbit slightly in response to the energy it adds to the probe, but the amount is unmeasurable due to the mass ratio between Jupiter and the probe. The speedup is therefore considered "free."
Google is your friend; see this page, this page, this page for more information.
Regarding your second question, the probe doesn't slow down again, and does do a very fast flyby. However, we know so close to nothing about Pluto that we don't have to get very close to get new information--for example, the resolution of the New Horizons cameras will exceed that of the best Earth telescopes (including Hubble) for 150 days. (Of course, it will take 4-9 months, depending on which estimate you like, to transmit the data back to the earth at the probe's minimum data rate--which it likely will use at that distance--of 800 bits/s.)