Ion Engine Propels Probe to Moon

lenin writes "The BBC is reporting that Europe's first moon mission, SMART-1, appears to be a success thus far. It also talks about the low-cost technology being used and the charged xenon (ion) propulsion system. Can TIE-fighters be far off?"

Comments

Ooh, IONs

[B3ryllium]

Ion propulsion ... that's fun. Has anyone heard of other probes being constructed that use other fun propulsion technologies?

(Frankly, the physics of using rockets in space has never made sense to me - how do they go anywhere? - but it seems to work, so that's fine.)

Re:Ooh, IONs

[dnoyeb]

For ever action their is an equal and opposite reaction.

Rockets move exactly in the same way an Ion propulsion engine would move. By forcing mass out the rear. Unlike jet or propeller, a rocket ejects its fuel as a means to propel itself.

Re:Ooh, IONs

[Anonymous Coward]

Frankly, the physics of using rockets in space has never made sense to me - how do they go anywhere? - but it seems to work, so that's fine.

Not too bright, are you? The physics is simple. Throw stuff opposite to the direction you want to go. To every action there is an opposite reaction.

Everything else is details. A lot of details :)

Re:Ooh, IONs

[DarkOx]

For every action there is and equal and oposit reaction.

Re:Ooh, IONs

[puetzc]

Of course you don't understand - after all, this time it really IS rocket science.

Re:Ooh, IONs

[Anonymous Coward]

HBP (human bean propulsion) works the same way *parapppapappapaparp*

-t

Re:Ooh, IONs

[quasi_steller]

(Frankly, the physics of using rockets in space has never made sense to me - how do they go anywhere? - but it seems to work, so that's fine.)

Rockets use the same priciple that ion propulsion uses, the law of action and reaction (one of Newton's Laws, can't remember which one off the top of my head). Basically matter is accellerated out the back of the engine (by chemical means in the chemical rocket engine, and by using electro-magnetic forces in the ion propulsion engine). This accelleration causes causes a force to be placed on the engine that is equal to, but oppisite in direction, to the force accellerating the matter.

To answer your first question, Deep Space 1 used ion propulsion.

Re:Ooh, IONs

[BTO]

Frankly, the physics of using rockets in space has never made sense to me - how do they go anywhere?

It's pretty simple, really. In the atmosphere, rockets work by pushing against the air, as you might expect. However, when the rocket leaves the atmosphere and enters a vacuum, or what we physicists call an "inertial frame," then your thrust is pushing against this inertial frame, which is kind of like what physicists used to call the "Aether." Aether has gotten a bad name, since Einstein proved that electromagnetic waves don't need to travel in the aether, but this has led to the misconception that aether doesn't even exist. Mach's principle shows that Aether is real, since it is what we need to push against to rotate and accelerate in space.

Re:Ooh, IONs

[Durandal64]

If you are wondering how rocket propulsion can work if Newton's laws dictate that every force generates an equal and opposite force, you're not distinguishing between force and acceleration. If you mass roughly 50 kg, and I hit you with a 500 kg Acme weight with a force of 1 000 N, you'll accelerate at 20 m/s^2, but the Acme weight will only accelerate at 2 m/s^2. Equal force != equal acceleration.

Re:Ooh, IONs

[WTFmonkey]

Kind of an asshole, aren't you?

I think what confuses some people is that we're used to pushing against something to go somewhere. People have a misguided idea that it's the exhaust pushing against the ground that makes a rocket go, but it's actually the rocket pushing against its exhaust that makes it go. Basically, you mix two things together in a chamber, and under high pessure you shoot ("throw" in the parent's words) the resulting gases out the back end, and away you go. There's no need to interact with the atmosphere which is why rockets work in space and propellers don't.

Re:Ooh, IONs

[Anonymous Coward]

WTF are you smoking!?

Re:Ooh, IONs

[Anonymous Coward]

ok, this is finally retarded enough. Rockets do not push against the air, they do not push against the "aether." Hell, they don't even push against the launching pad when they are on the ground.

Rocket exhaust (the flames, etc.) provide a force, yes, but THEY PUSH AGAINST THE ROCKET.

If you are standing on ice (wearing skates) and you throw a bowling ball away from you, you will slide in the opposite direction. The bowling ball doesn't need to hit anything for you to move.

Re:Ooh, IONs

[WTFmonkey]

Look at the dude's posting history. Read his comment and laugh. It's funny.

Re:Ooh, IONs

[rco3]

Oh, please. Everybody knows that rockets have to have air to push against, but aether? Please. Quit trying to fool the above poster with your farcical stories about aether.

Any respectable scientist knows that space travel is impossible anyway, that NASA never put any men on the moon, and that any satellite in orbit that you might THINK you see is really swamp gas, reflected off of Venus...

And as for my sibling posters in this subthread, you might wanna turn up the sensayumor knob in yer forebrain.

Re:Ooh, IONs

[Anonymous Coward]

One of the articles about the aerospike engines included a nice diagram that showed how the force vectors of the expanding gas and the shape of the nozzle combine to create a net force that pushes the rocket.

Re:Ooh, IONs

[FrostedWheat]

For ever action their is an equal and opposite reaction

I'm sorry, but that dosen't explain the curry from my local Chinese restaurant. The reaction is way bigger than the action. Perhaps they should have powered SMART-1 using that.

Re:Ooh, IONs

[Anonymous Coward]

what we physicists call an "inertial frame"

HAHAHA I don't believe you've been within 1000 feet of a physics classroom. An "inertial frame" or any type of frame of reference has nothing to do with air pressure. It's mindboggling how someone can get such a simple concept so screwed up.

To push and rotate in vacuum, you need to eject material under conservation of momentum. There is no aether and there is nothing to push against in a vacuum except what you bring with.

Re:Ooh, IONs

[kfg]

Hey guys, this stuff isn't just dumbass. A considerable amount of thought and understanding had to go into making it look that retarded.

In short, it's a troll. A real troll at that, not the pseudo trolls we usually see around here.

Not exactly the best troll I've ever seen, but in a way it's nice to see a Slashdoter make the effort to at least try to uphold the old traditions.

KFG

Re:Ooh, IONs

[TechnoGrl]

Has anyone heard of other probes being constructed that use other fun propulsion technologies?

Anyone care for a Reactionless Thruster ?

Re:Ooh, IONs

[kfg]

To perhaps give you an intuitive idea of what all this action/reaction stuff
people are talking about is imagine firing a gun.

It "kicks".

The expanding gasses push the bullet out one end, sure, but they also push the
whole gun back against your shoulder. If your shoulder weren't there . . .

Another example would be trying to hold onto a fire hose. If you've never had the opportunity just rent Roxanne. Then you can go down to your local Kaybee (or other) toy store and buy a cheap little plastic thing that puts this to actual
use in a rocket. Or go here if you're a do it yourself kind of guy:

http://bradcalv.customer.netspace.net.au/wrbook. ht m

KFG

Re:Ooh, IONs

[Anonymous Coward]

Sucker. You've been trolled. What's mindboggling is how easily you were taken in.

Re:Ooh, IONs

[jd142]

The article gives examples of other ion powered craft.

Re:Ooh, IONs

[Anonymous Coward]

You gotta think of two people in a vacuous space. They hold hands, and then push against eachother. Each floats away at a speed equal to the others. If only one pushed, they'd still float away from eachother at equal speeds.

Re:Ooh, IONs

[f97tosc]

Rockets use the same priciple that ion propulsion uses, the law of action and reaction (one of Newton's Laws, can't remember which one off the top of my head). Basically matter is accellerated out the back of the engine (by chemical means in the chemical rocket engine, and by using electro-magnetic forces in the ion propulsion engine). This accelleration causes causes a force to be placed on the engine that is equal to, but oppisite in direction, to the force accellerating the matter.

All means of propulsion -on Earth and in Space- use Newton's third law.

In practical terms, the difference is that Ion engines use energy from the sun, to accellerate small portions of matter (ions) over a long period of time.

Rockets use chemical energy to throw out matter, typically violently for a short period of time.

For these reasons Ion engines are predicted a bright future for travel over long distances (to the moon is unusually short in this context), there efficient use of energy wins out in the long run.

However, it seems unlikely that they could be used for lifting things into orbit; then you need to quickly accelerate to high speeds and get out of the athmosphere. Ion Engines are probably not suitable for chasing X-Wings around the Death Star either for that matter.

Tor

Re:Ooh, IONs

[Ohreally_factor]

>Ion Engines are probably not suitable for chasing X-Wings around the Death Star either for that matter. Easy. Install a flywheel to capture wasted energy when braking your TIE fighter.

Re:Ooh, IONs

[Anonymous Coward]

Like a balloon you fill with air. The inner pressure is pushing the balloon fabric in every direction, but the air inside it doesn't have anywhere to go. So, let go of the balloon, and the air inside it will now have a place to go - out of the balloon. The pressure still works in every direction inside the balloon by the air molecules pushing at it from inside. So when there is an opening in the "back" of the balloon, the air inside it will push the balloon forward from inside.

Re:Ooh, IONs

[Anonymous Coward]

The maximum thrust of an ion engine (or any rocket engine, for that matter) depends on the amount of matter ejected and the ejection speed (force = counterforce = mass x speed x speed). Since ion engines use extremely small amounts of matter, the push is mainly determined by the ejection speed of the ions. This, in turn, is dependant on the strength of the electrical and magnetic fields used to eject them. The theory of relativity limits this speed as less than lightspeed, BUT also predicts that the mass of ejected particles will be increased as their speed grows, therefore allowing theoretically limitless push, as long as one can produce neccessary voltage.

In other words: the maximum push of ion engine is only limited by the energy source and technical competence in high-voltage engineering, not by any inherent flaw in the technology. An ion engine is perfectly capable of lifting from Earth surface (or chasing X-Wings) assuming you have a suitable power source (nuclear reactor, most likely) and power trasporting/transforming equipment (wires and a voltage converter).

Of course, firing a stream of near-lightspeed ions in atmosphere might cause some radioactivity as they collide with other particles...

Re:Ooh, IONs

[Anonymous Coward]

I've got a question: Are the ions brought along with the satelite, or are they entirely extracted using the solar paddles? Because I think the limiting factor for every satelite is the amount of matter they bring along, and this could mean infinitely long missions :-)

Re:Ooh, IONs

[m3j00]

You don't have to trust newton's law to understand the concept. Imagine a closed cube with an explosion happening inside it. There is tremendous pressure on the inside of the cube, right? Well, what happens if one end of the cube is open? That means there is tremendous pressure on 5 sides of the cube and no pressure on the open side of the cube. This create an imbalance, since the side opposite from the open side is still getting pressure upon it, but the open side has none, so they cube moves away from the open side.

Re:Ooh, IONs

[f97tosc]

In other words: the maximum push of ion engine is only limited by the energy source and technical competence in high-voltage engineering, not by any inherent flaw in the technology. An ion engine is perfectly capable of lifting from Earth surface (or chasing X-Wings) assuming you have a suitable power source (nuclear reactor, most likely) and power trasporting/transforming equipment (wires and a voltage converter).

This is very true, but

1 All ion engines currently discussed use solar cells as their energy source. The whole point is that you only bring matter, not the energy source to accelerate it.

2 If you are prepared to bring an energy source as well, then you are basically back to the rocket case. Sure, you can bring a nuclear reactor, use heated atoms to drive a turbine and generate electricity, and then use the electricity to accellerate ions. But then it is more efficient to use your reactor to throw out particles directly, skipping the step of turbines and electricity generation. Btw researchers are working on such nuclear rocket systems. These would be much more efficient than anything we have today, but also politically problematic to say the least.

Tor

Re:Ooh, IONs

[Guppy06]

"Frankly, the physics of using rockets in space has never made sense to me"

You wouldn't happen to work for the New York Times, would you?

Re:Ooh, IONs

[B3ryllium]

Is that a job offer? Because I could really use the money.

(note that the above contains intentional grammatical no-nos, designed to indicate my overwhelming potential as a New York Times editor.)

Re:Ooh, IONs

[Anonymous Coward]

Those nuclear rockets can't directly accelerate the particles to near-lightspeed, though. You'd still need the ion engine for that.
Fusion power would be ideal for this, as electrical power generation is more direct from the plasma.

Re:Ooh, IONs

[Anonymous Coward]

The fuck? You're not pushing against any "Aether" to rotate and accelerate in space. You're literally pushing against the flaming gas coming out your ass-end. Much like you just did to produce your comment.

Re:Ooh, IONs

[Anonymous Coward]

YHBT. YHL. HAND.

Re:Ooh, IONs

[Guppy06]

Actually, I was thinking more along these lines.

Re:Ooh, IONs

[barakn]

other fun propulsion technologies?

My favorite proposal from the near past was the magnetic bubble. Create a large static magnetic field - a simple dipole will do- in space, and then fill it up with plasma. The plasma causes it to expand greatly in size, which is important because the dipole field decays as r^-3. It would act much like the Earth's own magnetosphere with a shock upwind and a long tail. But unlike at Earth, this magnetic bubble can be oriented in any direction. It has been compared to a balloon in operation.

Re:Ooh, IONs

[uberdave]

They were brought along, or more accurately, they are created from a supply of xenon that is brought along. The energy used to ionize the xenon and accelerate the ions comes from the solar panels.

Re:Ooh, IONs

[barakn]

I forgot the most important side effect. The magnetic bubble is very good at deflecting even high-energy ions and electrons, i.e. just about everything besides neutrons, neutrinos, and electromagnetic waves like UV, x-rays, or gamma rays. This type of radiation shielding seems like a natural for a mission with astronauts.

Re:Ooh, IONs

[Ealienation]

fyi you got your equations wrong -- you meant mass flow rate (aka m_dot) times exhaust velocity gives you thrust .. notice that the units on this end up correct (mass*distance/time^2) whereas the mv^2 gives us Joules (in metric) aka energy - infact, you might recognize 1/2 mv^2 from highschool physics.

Also - as far as light speed goes - yes, I guess your particle mass would approach infinity, but then so would your power requiremnent (its not just a voltage difference), wouldn't it? And even a nuclear reactor can't provide inifite power.

Also, generally ion engines have charged plates to accelerate the ionized fuel, these would wear out pretty quickly if you were bombarding them with infinitly massize particles moving at light speed .. even if they were made out of "unobtanium."

Finally, practically speaking ion engines CANNOT function in atmospheres - the ambient pressure of an atmosphere will "out push" the pressure produced at the mouth of the thruster by the thruster. With a nuclear reactor - I don't know - I do agree that it'd be nice if someone would cough up the cash for that...

Re:Ooh, IONs

[Anonymous Coward]

For every action there is and equal and oposit reaction

which is why trying to unsubscribe from spam results in your mailbox overflowing -- right?

Re:Ooh, IONs

[fucksl4shd0t]

But then it is more efficient to use your reactor to throw out particles directly, skipping the step of turbines and electricity generation.

I am not a rocket scientist, but it appears that you've oversimplified the problem.

Can't use the nuclear reaction directly while in the atmosphere, too much fallout. That's why we use chemical rockets in the first place (well, that and the fact that nuclear rockets haven't even been built yet). Suppose we could stick a small nuclear reactor and an engine on a single box and launch it into orbit. That eliminates the space shuttle's current booster system and massive fuel tank.

The ideal earth to moon shuttle should be able to take off from the surface of either body and fly all the way to the surface of the other body, and hopefully have enough reaction mass left to return (not likely, I suppose). This shuttle can't have a bunch of boosters and big fuel tanks that it drops into orbit on its way. When you have to shed 90% of your weight just to make it all the way up, you're operating very inefficiently.

In my opinion, any engine that has the potential to take us from surface to surface earth to moon without all the clumsy boosters is an engine that should be thoroughly pursued.

Then we can build, in orbit around the moon (or somewhere else in the vicinity) the big interplanetary vessels with the nuclear rockets.

Re:Ooh, IONs

[Anonymous Coward]

Or, put differently, there's a difference in pressure between one side of the exhaust chamber and the other side (where "whatever" leaves the chamber). Because the pressure is higher on the forward side of the exhaust chamber, the spacecraft is pushed in that direction.

Re:Ooh, IONs

[Ratphace]

Ion Engines, 0-600,000 in 2.2 light-years! ;)

Re:Ooh, IONs

[Anonymous Coward]

Come on, you'd have to be an idiot, or had your sense of humor tragically removed, to take the post seriously. It was obviously meant as humor, in the Annals of Irreproducible Research fashion, and it was quite funny at that. What's even funnier is that people are responding to it as if someone could actually hold such bizarre ideas seriously.

Dupe !

[Anonymous Coward]

Here's the original.

Tie fighters

[panurge]

If Tie fighters had the acceleration of the Smart-1, Lucas Skywalker would have had nothing to fear. There's obviously some sort of competition on for the slowest flight to the Moon. The acceleration is even lower than that of the Smart car.

Yes, I do know why ion engines are a good idea. Just leave Star Wars out of this.

Re:Tie fighters

[Christoff84]

Its not the TIE fighter you need to be scared of, its the guy running towards you with a long beam of light screaming MAY THE FORCE BE WITH ME!

Re:Tie fighters

[geggibus]

0.2mm/s^2 ....

Re:Tie fighters

[johoho]

see this link why the auther made the analogy to star wars.

Wiktor

Re:Tie fighters

[Anonymous Coward]

TIE means Twin Ion Engine....

Re:Tie fighters

[teridon]

Just for kicks -- SMART-1 will travel an average of 21 mph towards the moon.

Distance to moon = 384,000 km

time to moon = 15 months

And thanks to the amazing Google calculator, I didn't have to covert anything!

Re:Tie fighters

[GlowStars]

A real Smart would be faster (and manned!!).

Re:Tie fighters

[nomel]

He said it has the same accereration, not the same top speed :) In space, the ion engine should be able to accerelate to a much higher speed than 21mph.

Re:Tie fighters

[Anonymous Coward]

It doent go straight, so the distance is bigger and the speed is also bigger

Re:Tie fighters

[myom]

Does teh dvorak keyboard acceRerate your typing, just as teh qwerty keyboard makes me spell teh word "teh" as "teh"

Re:Tie fighters

[nomel]

hahah...damn...I botched accelerate...twice! L is next to R, and I was sitting strange on my bed with my laptop in the dark, and didn't watch what was typing. I know...excuses excuses.

I'm only slightly faster than I was on qwerty...but, dvorak is MUCH more comfortable for me. There are problems with it when you have very cold hands though. :)

Re:Tie fighters

[Stonent1]

I thought it was because it looked like a bow tie...

Karma Whore for the Non-Star Wars Obsessed

[dupper]

Twin
Ion
Engine
-
F
i
g
h
t
e
r

Re:Karma Whore for the Non-Star Wars Obsessed

[fucksl4shd0t]

Yeah? Well, for your information TIE Fighters don't have any kind of shielding, and only 1 out of 4 survive to retirement. They're fast, and they're extremely lightweight, and *very* maneuverable, but they don't have any shielding. The pilots fly in a spacesuit, and that's their atmosphere. None of the pressurized bullshit X-wings with their shielding. That's how come the TIE fighters outran the X-wings and even flew circles around them at the Death Star. It's also why if you hit one it usually blew up, whereas an X-wing could sustain a lot more damage.

Re:Karma Whore for the Non-Star Wars Obsessed

[Anonymous Coward]

If you watch the films again, you may notice that the X-wings usually blow up when shot, as well.

Now in the computer games, it was a bit different...

Fusial Thrust

[AllenChristopher]

Before we can build X-Wings, we have to figure out what the hell "Fusial Thrust" means.

Re:Fusial Thrust

[marine_recon]

thats the easy part. the hard part is finding someone who knows how to build a hyperdrive

Re:Fusial Thrust

[Junior J. Junior III]

Thrust that comes out of the fuselage?

Re:Fusial Thrust

[twiddlingbits]

If you know not Fusial Thrust what is, no Jedi are you! Comes from the Force it does, very strong power, Dark Side it leads to can.

Re:Fusial Thrust

[Anonymous Coward]

I think correcting people on mock Starwars quotes is what really makes someone fail at getting laid.

Re:Fusial Thrust

[Anonymous Coward]

"Dipshit," I don't think your own hand would fuck you.

Re:Fusial Thrust

[Anonymous Coward]

I had suspected that the engines actually use the plasma produced by the X-Wings centrifugal vapor fusion reactor core rather than using the covnerted electrical power drive an energization reaction like that in the TIEs. Hence fusial, from fusion, since fusial isn't actually a word.

This isn't so much useless blather as scientific allegory. False, but partially mappable.

Sigh

[Anonymous Coward]

Soon we will really WILL have a bunch of brits on the 'DeathStar' going room to room, inquiring what the hell is going on.

"I AM YOUR FATHER!"

Its about time.

[andcarne]

Ion propulsion technology has been around for quite some time, but has not been used for much else then the deep space probes. Its nice to see it getting some more use. Its also good that other countries are getting more involved with space. Its been far too limited with really only one country going up, since Russia does few launches anymore. I just hope the space program starts to pick up finally after the shuttle tragedy.

Re:Its about time.

[dex22]

Russia does far more launches than the US.
Russia does them much more safely. In manned launches, they have something like a 99.9% success rate (one launch mishap in over 1000 launches). The US has had two mishaps in about 115 launches.

Re:Its about time.

[IAR80]

Ion drives were also user in the European Artemis spacecraft which is geostationary. Too bad the Arian e launcher had a problem reducing a lot the "life expectancy" of the satelite who had to use most of its fuel to reach the geostationary slot. http://www.spaceandtech.com/digest/flash2001/flash 2001-056.shtml

Re:Its about time.

[IAR80]

If you think the US is bad then look at the european launchers.

Re:Its about time.

[troc]

Yeah, That dammed Ariane 4 rocket was only the most successful, accurate, reliable launcher ever.

Nasty horrid Europeans.

Sure Ariane 5 has had some teething troubles but don't mock the Europeans, they are the ones who made space commercial. Ariane is much more reliable than the Delta or Atlas Centaur launchers the US uses and whilst the shuttle is quite reliable, it's a ridiculously expensive way to put a commercial satellite in space.

Re:Its about time.

[jdhutchins]

You're russian history is incorrect. They have had several mishaps. The ones that I can think of off the top of my head are Soyuz 1 and Soyuz 11. They have probably had somewhere between 150-200 manned launches. We'll hav change your definition of "launch mishap" to "the rocket went up but the people didn't come down alive".
We have had two accidents in our space program (3 if you count Apollo I, but in the above definition, it doesn't count)
The Russians do more launches than we do. In the past, they've done more manned launches than we did. Since the past 5 years, I'd say that we've probably done about the same number of manned launches.

Re:Its about time.

[Anonymous Coward]

You are russian history is incorrect?

Re:Its about time.

[psychosis]

I'm not sure that they do as many manned launches, though - they're so cash-strapped, they couldn't even lauch a replacement crew or supply replenishment mission a year or so back, if I remember.

Also, if the 1000 lauch figure you state includes unmanned launches, I think that the US has them beat by a long shot... I'll have to look up some numbers, but I think you're mixing apples and oranges.

Re:Its about time.

[RayBender]

You're russian history is incorrect. They have had several mishaps.

In more than 35 years of spaceflight the Russians have had something like 4 fatalities, and 3 (?) accidents (including one where the crew survived a booster failure in mid-flight - the stage didn't separate). In comparison to the U.S. record this is remarkably good. They have also flown more people for longer periods of time.

Since the past 5 years, I'd say that we've probably done about the same number of manned launches.

The same number of launches as the U.S., with a total budget of something like 200 million dollars, a factor of 30 less money. That's pretty impressive. The simple turth is that the U.S. is a second-rate space power.

Re:Its about time.

[Anonymous Coward]

"In more than 35 years of spaceflight the Russians have had something like 4 fatalities, and 3 (?) accidents (including one where the crew survived a booster failure in mid-flight - the stage didn't separate). In comparison to the U.S. record this is remarkably good. They have also flown more people for longer periods of time."

They were also the first at everything in the space race apart from the manned moon landing... and if you believe that happened you'll believe anything.

Seriously, is anyone still fooled by those dodgy special effects and the lame script writing?

"The simple turth is that the U.S. is a second-rate space power."

Always have, always will be. TBH, I wish they weren't, that way they could all fuck off and liberate Venus; and us by proxy.

Re:Its about time.

[ChuckleBug]

In more than 35 years of spaceflight the Russians have had something like 4 fatalities, and 3 (?) accidents (including one where the crew survived a booster failure in mid-flight - the stage didn't separate). In comparison to the U.S. record this is remarkably good. They have also flown more people for longer periods of tim

True, but the number of fatal accidents is about the same - NASA just had more people on each of the fatal voyages.

I don't think the numbers are large enough to reach any justifiable conclusions about the relative safety of the two programs. People will be lost as long as we put them in space; How many over a certain period of time is partly bad luck. (No I'm not saying NASA hasn't had some serious problems - Just that the difference between them and the Russian space program are not so cut and dried.)

Re:Its about time.

[Anonymous Coward]

True, but the number of fatal accidents is about the same - NASA just had more people on each of the fatal voyages.

The fact that they put more eggs into one basket makes things even worse. If you're trying to defend/apologise for NASA, mentioning this has the opposite effect from what you intended.

Re:Its about time.

[Anonymous Coward]

This is not true, it's been a while since I researched this, but I remember one accident involving one crew member. And another involving three crew members. While there have been other very serious accidents, they have not resulted in fatalities, as safety procedures have worked correctly. One such accident used the knowledge gained from the US Apollo 1 (?) fire, to save a crew after stage seperation failure. (quick escape procedures).

This of course is true as long as you don't count ICBM research programs. Of which Russia has a very bad record. (One accident involving 100+ deaths)

Re:Its about time.

[fucksl4shd0t]

The simple turth is that the U.S. is a second-rate space power.

What're you talking about? We've got 5, no wait, 4 Space planes. How many do you have? Ah ha!

Re:Its about time.

[gbjbaanb]

so what you're saying is that NASA is the Microsoft of the space industry, and Russia, Linux...

Re:Its about time.

[RayBender]

What're you talking about? We've got 5, no wait, 4 Space planes. How many do you have? Ah ha!

Actually, we have three. And they have an annoying tendency to blow up and kill their crews, and hence they're currently grounded. Not much to be proud of.

Re:Its about time.

[RayBender]

hey were also the first at everything in the space race apart from the manned moon landing... and if you believe that happened you'll believe anything. Seriously, is anyone still fooled by those dodgy special effects and the lame script writing?

Yes, I damned well belive the Moon landings happened. I've done chemical analysis on the rocks; I've met some of the astronauts; my best friends dad helped build the LEM at Grumman. So yeah, they happened.

I'm not sure what annoys me more: idiots like you who don't think it ever happened, or the idiots in the White House, Congress and the public who didn't think it's important enough to keep funding.

I guess we're living in a society where our greatest achievements lie behind us, rather than ahead of us. In that situation I shouldn't be surprised that there are fools like you who try to make themselves feel better by claiming the achievements of the past never happened.

Re:Its about time.

[Anonymous Coward]

Er what? Perhaps some statistics might help.

Re:Its about time.

[Anonymous Coward]

I think you are living in a society where people are satisfied when great achievements happen in Hollywood. Looks like people don't really care, as long as it's a good show...

Re:Its about time.

[FrzrBrn]

Oh, great, so how long is it going to be until the first "In Soviet Rus^H^H^H Linux..." joke?

Re:Its about time.

[ChuckleBug]

The fact that they put more eggs into one basket makes things even worse. If you're trying to defend/apologise for NASA, mentioning this has the opposite effect from what you intended.

Well, since I'm not trying to defend or apologize for NASA, I'm on solid ground.

I'm just trying to add perspective - If we're talking about which country has shown better safety on a per mission basis (which I think is reasonable since it's doubtful anyone would survive a spaceflight mishap), the number of failure is a better comparison. For the engineers who are trying to figure out what caused a failure, the number of people killed doesn't have much bearing on the problem.

So if you want to say NASA is worse because more astronauts have died, I'd agree. If you want to say that the Russians have more reliable engineering, I'd say that's not clear from comparing numbers of accidents.

Re:Its about time.

[ChuckleBug]

This is not true, it's been a while since I researched this, but I remember one accident involving one crew member. And another involving three crew members.

My point is that when you're talking small numbers of accidents, you don't have enough data to draw many conclusions. 3 to 1, 3 to 3, 4 to 3, whatever.

Re:Its about time.

[Anonymous Coward]

In comparison to the U.S. record this is remarkably good...

Unless you consider the numerous cosmonauts who tied in flight tests, of cancer, etc. Ground personel who died in explosions ... I've worked w/ the RSA on ISS - they are NOT very safety conscious (eg Mir, etc) and they've got a tight budget. In short, I'd rather be an astronaut.

Re:Its about time.

[Rotten168]

No, the US is like UNIX and Russia is like CP/M.

Re:Its about time.

[Rotten168]

ridiculously expensive way to put a commercial satellite in space.

Actually, yes they are. It's a shame that it took a shuttle disaster to get us to see how unmanned missions makes more sense.

Re:Its about time.

[expro]

Perhaps one thing even more annoying is people who take themselves too seriously and cannot recognize shallow dry humor and insist on making a troll out of it.

Or alternatively it is even more amusing than the AC post.

Re:Its about time.

[mi]

Russia does far more launches than the US. Russia does them much more safely.

Nitpicking: most were done by the Soviet Union, not Russia. The actual cosmodrome (still the main one) is in Kazahstan, BTW.

Real point: But that aside, you are forgetting at least one accident, which left hundreds of people on the ground dead -- the rocket exploded. Soviets also had the tendency to announce the launches well after the fact, so the failed ones will remain unknown. Don't trust the evil empire's propaganda...

Final mumbling: Although cheaper in absolute terms, the Soviet space program was a bigger strain on the country's economy, indirectly responsible for more deaths and sufferings. Then, again, may be, the glory was worth it... I don't know.

TIE

[CGP314]

It also talks about the low-cost technology being used and the charged xenon (ion) propulsion system. Can TIE-fighters be far off?

Yup, that's how technology goes, straight from moon probe to TIE fighters. No intermediate steps necessary. No life support, no radiation shielding, necessary. I can't wait to buy my A-Wing.

Re:TIE

[Bobulusman]

Not to be an over-obsessed SW geek, but the TIE fighter didn't have a life support system. That's why the pilots needed those air masks, while the X-wing pilots got the open-air helmets.

Re:TIE

[FauxPasIII]

Not to mention particle weapons. Or force fields and faster-than-light travel. (for your A-Wing, yes, I know TIE fighters are unshielded and sublight)

Re:TIE

[gl4ss]

dude, tie fighters don't have life support(the pilot needs a full space suit)! that's why they're so cheap at your local imperial clearing sales.

geez, the people on slashdot these days!

Re:TIE

[dolo666]

I am going to buy this technology and use it to dessimate that pesky web slinger once and for all!!!!

We don't need no stinkin' micro-meteor deflection systems, no how! :)

Re:TIE

[inertia187]

Not to be an over-obsessed reality geek, but even the Space Shuttle had life support in addition to the pressure suites they wear on take off and landing. The suits are in case of sudden decompression.

In Soviet Russia, early cosmonauts didn't wear pressure suites to display the superiority of their space program. They needlessly lost people due to that practice, and have changed to using pressure suites as result.

Also, remember the TIE figter pilots were clones, so they would wear a mask even if they weren't assined to be pilots, like any other storm trooper.

Re:TIE

[Bobulusman]

It's not a big deal, but I'm 99.99% sure the TIEs didn't have life support in the movies. They were crafts designed to superior speed and maneuverability by stripping away all the non-essentials, like shields or hyperspace-capability.

I don't remember where they said they were clones...Unless you are just assuming that after the events of "Attack of the Clones"

Re:TIE

[JamesP]

Ion Engines are slow. Thats why TIE advanceds have Hyperdrive...

Re:TIE

[Anonymous Coward]

My toddler has a hyperdrive. It's fueled by sugar.

Re:TIE

[Anonymous Coward]

Don't worry, you're just an over-obsessed idiot.
The suits are in case of flying the TIE fighter. The fighters themselves have no life support, period. If the pilots removed their masks, they'd suffer explosive decompression.

Re:TIE

[Pharmboy]

My toddler has a hyperdrive. It's fueled by sugar.

That was actually funnier than all the garbage above.

Re:TIE

[ScottForbes]

I find your lack of faith... disturbing.

Re:TIE

[fucksl4shd0t]

In Soviet Russia, early cosmonauts didn't wear pressure suites to display the superiority of their space program.

Actually, In Soviet Russia, pressure suits wear YOU.

Re:TIE

[ralphclark]

There is no such thing as explosive decompression. The blood vessels in your lungs and eyes will rupture, and your heart will cease when it can no longer maintain blood pressure. Then your corpse will slowly freeze-dry. But there is no messy explosion.

Re:TIE

[jellomizer]

This is absolutely amazing you were able to bring Star Wars "In Soviet Russia" and Attack of the Clones all in the same topic without being off topic. Kudos to you.

Re:TIE

[Anonymous Coward]

Yeah, the parent's right. Don't you know anything!?

Re:TIE

[Anonymous Coward]

Very true. You can go from 14 PSI to 0 and back again with only a few popped blood vessels and an interesting hallucination. The other direction, however, going from, 14 PSI to say 100 PSI, like when one is hundreds of feet under water is a real bad deal, unless all cavities are filled with water. Then, it's not as bad. Excess pressure still pretty much sucks.

Re:TIE

[DoctorRad]

Cue Crazy Watto.

Matt...

Obligatory. . .

[Limburgher]

"But Ion engines can never acheive fast accelleration"

(sigh) Then the Emperor has already won.

Re:Obligatory. . .

[Anonymous Coward]

"He's heading for that small moon."

"That's no moon..."

Re:Obligatory. . .

[fucksl4shd0t]

You must do what you feel is right, of course.

Ion drive is cool, but...

[JeffMagnus]

Sure the Ion drive is a really neat addition, but it's soooo slooooow. It's going to take them 15 MONTHS to get there! And the payload isn't really greater at all. It takes longer to get any large loads going. The US space program got people to the moon and back in what...2 weeks? It may be slightly more economical, but it just doesn't seem practical.
Hopefully they can perfect the ion drive, however through this to increase the speed and payload capacity. Then we might have something really cool... (until the anti-matter reactor comes online...)

Re:Ion drive is cool, but...

[lurker412]

What's the hurry? The moon will keep. Think science, not Star Wars.

Re:Ion drive is cool, but...

[andcarne]

There really is no way to speed it up, that is economical. This technology is mainly for use in long distances, since it would take less time to go really far. This is just a test bed for it. The moon will still be there in 15 months.

Re:Ion drive is cool, but...

[adeyadey]

This is really a test bed for the ion-drive technology - although even on this mission, its effective to do it this way, once in lunar orbit the drive can make slow adjustments to cover the whole surface, without having to carry huge amounts of propellant. Over LONG periods of operation, the ion drive is something like 10 times more effective in terms of fuel carried vs thrust given compared to chemical rockets - and that figure is set to improve as research progresses. SMART-1 is an important step in that research. The Ariane-5 launch rocket is a fraction of the size/cost of the Apollo/Saturn-5's..

In the future missions you will see these sorts of drives giving much faster flight times to Mercury, Mars, Jupiter, Saturn.. - although for the outer system you may need nuclear instead of solar power.

Yes both this and parent are dupes from previous thread..

Re:Ion drive is cool, but...

[Anonymous Coward]

That's how ion drives are so economical. While most rockets burn a huge amount of fuel quickly then coast, an ion drive continues to "burn" (granted the fuel isn't combustible, the xenon ions are accelerated with electric plates, etc) for years upon end. Hence after a few weeks the ion driven probe would achieve rediculous speeds. Consider the recently ended Deep Space One simulation at JPL. They had the drive running for a few years straight, if I remember correctly as I'm too lazy to double check. Even though these drives have sub newton thrusts, after that long the probes would be well past speeds unattainable by conventional rockets.

Re:Ion drive is cool, but...

[jd142]

The moon will still be there in 15 months.

That's what you think. Ooops, I've said too much already.

Re:Ion drive is cool, but...

[Clueless Moron]

slightly more economical???

This project cost just 100E6 Euros. That's about one quarter the cost of a single shuttle launch, never mind the astronomical costs of each Apollo mission.

Personally I'd much rather see 4 new projects like this and one fewer shuttle launch.

Re:Ion drive is cool, but...

[Manhigh]

Smart is solar powered, and likely on the order of 1's or 10's of kilowatts.

Once you start tying ion propulsion to a nuclear power source, you start being able to achieve higher thrust levels. SMART only uses a little over 1kW of power.

Its very practical.
Ion propulsion can take longer than chemical (although this is not always the case) but it has a much higher specific impulse, and therefore a much lower propellant mass fraction. That means you can get more mass to a destination given the same launch mass, or, take the same payload and use a much smaller (cheaper) launch vehicle.

Re:Ion drive is cool, but...

[Clueless Moron]

The moon will keep

Sheesh, you dont know much about green cheese, do you?

Re:Ion drive is cool, but...

[nametaken]

Maybe it's not really as economical when you consider peak staffing for "mission control" for 15 months instead of two weeks? I don't know, just a thought.

Re:Ion drive is cool, but...

[isorox]

15 months? The moon vanished 4 years ago. Whats left is a giant lightbulb to limit peoples fear

Re:Ion drive is cool, but...

[a.deity]

15 months from now, the moon'll be there, but there will be a C, an H, and part of an A carved on it.

Re:Ion drive is cool, but...

[Anonymous Coward]

The maximum thrust of an ion drive depends on the mass and speed of ions ejected (force = counterforce = mass x speed x speed). On the other hand, speed only depends on the energy fed onto the electrical and magnetic fields which accelerate the ions. And the mass of ions increases with their speed according to the Theory of Relativity.

In other words, connect that antimatter reactor to a good converter and that to an ion engine, and you've got Acceleration :). On the other hand, connect a solar panel onto the ion engine, and you 've got acceleration :(.

Summa summarum: it's a good thing that they're developing the ion engine now, so it's perfected by the time an antimatter or fusion power plant is ready for use. Using nuclear power to heat hydrogen and then ejecting that (as the most common suggestion for a nuclear rocket goes) is, IMHO, idiotic; you have to carry absurd amounts of "reaction mass" on top of whatever fuel the reactor uses, and once it runs out, you're helpless, even if the reactor is still full of energy...

Chemical rockets are crude, slow, uneconomic and inefficient; ion engines are elegant, fast, economic and efficient. The faster we get rid of this ridicilous need for a hundred-meter tall rocket just to reach the orbit, the better.

Re:Ion drive is cool, but...

[lurker412]

Hmmm...guess not. I've had a piece in my refrigerator for about seven years and it smells just like new...

Re:Ion drive is cool, but...

[Dr. Cody]

>>The moon will still be there in 15 months.

>That's what you think. Ooops, I've said too much already.

Hey, give me some time--all I've gotten done is "C-H-A"

Re:Ion drive is cool, but...

[bheerssen]

What, you can't wait? It's not like you'll be going anywhere.

Re:Ion drive is cool, but...

[rickbrodie]

Correct me if I'm wrong, but does this probe not have to reach the moon by spiralling out from the earth? If this is the case, then the actual distance that it will have travelled would be hugely greater than the "as the crow flies" distance. It's not as if you can just point the probe at the moon and give it a push, these orbit changes are pretty awkward.

Re:Ion drive is cool, but...

[adeyadey]

It depends whether you to get ther fast, or cheap. In the case of Apollo they *had* to use big rockets, and pay the cost, because the humans on board had limited supplies of air, etc. This is a science mission thats going to take years anyway - it doesnt matter too much that it takes a year to get there. Its only going to cost 110 million euro - peanuts in planetary exploration terms. Slow acceleration may mean a longer path, but big fuel savings. Also for longer missions, Ion drives will actually overtake chemical rockets, just because they can economically burn the engines for months/years - with chemical rockets its usually one or two or a few big burns, then thats it.

Re:Ion drive is cool, but...

[mr_luc]

I agree -- this shit is good shit.

But unfortunately, the fact is that sending an unmanned probe to the moon IS more economical! *It* can be built this cheap. Unmanned missions can be optimized to pieces, since they have such flexible requirements. Hell, you could even make the majority of unmanned probes distributed, using multiple smaller ones for redundancy and linking them together.

There's a certain point beyond which manned missions can't be optimized. Not that there isn't room for improvement in the shuttle system -- personally, I'd like to see some kind of electromagnetic accelerator that smoothly whisks space planes to extreme speed, from the ground; cut the cord with multistage launching altogether.

But this comparison -- it's apples to oranges. It is fucking EXPENSIVE to put people in orbit, in a vehicle that provides the cargo space and utility that the space shuttle does. And so far, unfortunately, no one has really improved on it for what it does.

ion engine limitations

[Sneftel]

As interesting as ion engines sound, it seems like they might be rather limited in use. After all, with such low acceleration, procedures such as leaving the orbit of a planet or moon might be impossible, or at least take decades. Anyone with more specific knowledge than the Beeb wanna weigh in?

Re:ion engine limitations

[Shihar]

While the Ion engine is very slow, it actually turns out to be faster then most engines in the long run. For a normal engine they generally burn real quickly then the object just coasts to wherever it is going. With an ion engine they can burn for very long periods of time. Over long distances it is better to burn for a long time with a slow acceleration then it is to burn quickly.

Even better, if you are doing something like flying to Mars, an ion engine combined with a normal engine has a lot of potential. Just strap a big old disposable solid fuel engine onto your spacecraft and let it burn dry. This will get you well on your way to your destination. Dump the solid fuel engine and continue to burn with the ion engine. You will get to where you are going fairly quickly.

Re:ion engine limitations

[Clueless Moron]

Leaving orbit is not a problem; it just takes a lot longer. Remember, there is no friction in space.

The point of ion drive is that it has waaaay higher efficiency than chemical rockets. Momentum is mass times velocity, so by pumping up the velocity you can correspondingly reduce the mass. That's what Ion drive does. It spits out atoms at ridiculous speeds.

Consider a chemical rocket. It very quickly gets you up to speed, but after that you just coast.

Now consider a drive that has, say, only 1/100th as much acceleration, but can run 10000 times longer. It'll take a long time to use up that fuel, but when you're done you will be going 100 times faster than the chemical rocket.

Obviously Ion drive is only useful once you're already in orbit, but if time is not an issue it's hard to beat.

Re:ion engine limitations

[TrippTDF]

Keep in mind, this is the first ion engine in use. I'm sure that in time we can refine the technology, possibly combine it with rockets even, and you could have yourself a nice, efficient yet effective engine.

I know next to nothing about this technology, but perhaps ion engines make more sense as maneuvering thrusters or some sort of back up system in case the main engines have a failure. Perhaps deep space probes will carry a secondary ion engine with their rockets incase something goes wrong...

I'm sure this is a first step. I'm planing on waiting for a TIE Interceptor before I make a purchase, though.

Re:ion engine limitations

[Anonymous Coward]

Actually, there is friction in space. There are trace particles floating out there that will push against a spacecraft as it moves. Especially within a solar system. It's just very, very little friction. If an engine is TOO weak, it wouldn't matter if the fuel lasts 1 million years. It wouldn't get very far.

That said, even an ion engine produces many orders of magnitude more thrust than the minimum required to move.

Re:ion engine limitations

[Anonymous Coward]

Ok. You've opened the can, now come the worms. As I seem to recall, an ion drive mission left the galaxy some time ago. Yes, the acceleration is slow but it keeps accelerating over a long period, going faster and faster. After 2 years of accelerating (and no expectations of slowing it down at all), it was expected to reach it's destination in another 30-40 years. It's speed? Approximately the distance from the American east coast to the west coast in about 5 minutes. Not warp speed, but not exactly pokey either.

Unwarranted Extrapolation

[Anonymous Coward]

Can TIE-fighters be far off?

Sorry to disappoint you, but yes.

Damn space cadet!

elevator

[spectrokid]

If we combine this with the space elevator, we can send shit to the moon on 6 AA batteries!!!

Re:elevator

[Anonymous Coward]

Oh shit, that was funny. WIsh I had mod points today. It's not often something on /. makes me laugh out loud.

Re:elevator

[Anonymous Coward]

No, all we need to do is combine the space elevator with some monkeys.

Re:elevator

[Anonymous Coward]

We know it's you, spectrokid. Shut the fuck up.

Re:elevator

[Anonymous Coward]

I personally think THIS parent is spectrokid attempting to make it look like he is being attacked. Clever ploy...

Re:elevator

[Anonymous Coward]

Nah, it lacks the obvious similarities in writing style that the first child post had. spectrokid was just posting a positive AC reply to himself to drum up some +1, funny moderations. It wasn't a very clever ploy at all.

Re:elevator

[fucksl4shd0t]

f we combine this with the space elevator, we can send shit to the moon on 6 AA batteries!!!

Well hurry it up, dude! I gotta go, real bad!

Re:elevator

[smithmc]

If we combine this with the space elevator, we can send shit to the moon on 6 AA batteries!!!

One would hope that we can find more interesting things to send to the moon that shit...

Not for Tie Fighters

[Frequency Domain]

Ion propulsion systems wouldn't be any good for fighter craft. They use very low accelerations, integrated over large periods of time. This makes them a good candidate for interplanetary flight, where you have weeks and months to build up large velocities with the small acceleration, but really crappy for combat where you want to be able to accelerate quickly. Well, maybe you don't, but I do.

Re:Not for Tie Fighters

[Exiler]

TIE = Twin Ion engines

Link

[Sir Haxalot]

The same story at Spaceref.

ionize xenon atoms?

[ddd2k]

anyone else wondering where such a small system is getting the energy needed to ionize a large amount of xenon atoms?

Re:ionize xenon atoms?

[WolfWithoutAClause]

Actually, no big mystery, it has enormous solar panels 10s of meters long.

Re:ionize xenon atoms?

[gaijin_]

The concept relies on using power from the solar cells to make the force. This is opposed to carrying fuel.

Using this system only a very small amount of mass is needed to accelerate the craft to quite high velocities, because the energy isn't lifted from the gound but produced in orbit.

On a normal probe the energy for popultion would reside in the fuel carried in tanks, here it resides in the rather large fusion reactor at the center of the solar system.

Re:ionize xenon atoms?

[andcarne]

It still does carry fuel, the xenon gas. It just uses very little to go any distance.

Re:ionize xenon atoms?

[Anonymous Coward]

From the kick-ass large solar panels. Glad that you asked.

Re:ionize xenon atoms?

[Anonymous Coward]

It still does carry fuel, the xenon gas.

That's not fuel - it's reaction mass.
Fuel is something that provides energy.

Re:ionize xenon atoms?

[Anonymous Coward]

They use giant solar panels. European recycling mentality :-)

Re:ionize xenon atoms?

[MasterShake]

Actually, the xenon gas is reaction mass not fuel. Fuel implies that energy is bound up in the material. (Useable, we don't have a good supply of anti-xenon to use the xenon as fuel)

Yes, Alice, that's right...

[Tumbleweed]

TO THE MOON!!!

Friction

[RetroGeek]

Can TIE-fighters be far off?

There will be no TIE fighters until we have friction in space. To be able to turn like an airplane in an atmosphere you need something to react against.

Re:Friction

[terminal.dk]

Wrong.

You just need to have enough mass you can eject in some direction. That is called propulsion. Just collect enough light, and you will be doing well.

Re:Friction

[gregfortune]

Not at all, you just need to generate massive thrust in arbitrary directions. The easy way to do this is generate thrust out the back and then have a thruster at the front-top, front-bottom, front-left, and front-right that allow the vehicle to spin on its center.

Re:Friction

[geekoid]

Not necessarily.

What if someone invented a 'Gravity reflector' that replys gravity? then you could us the gravity as the force your reacting to in order to move like an aircraft.

Sure, It sounds lame from me on slashdot, but if any greate Sci-Fi author had the same idea, you would think it was the coolest idea since cat doors.

Re: Friction

[shoemakc]

There will be no TIE fighters until we have friction in space. To be able to turn like an airplane in an atmosphere you need something to react against.

AFAIK, space isn't a perfect vacuum, there is matter in space, just that it's concentrations are extraordinarily low. You'd need either a very large control surface, or some method of increasing friction over what limited matter there is. Why do we use brake pads on a car and not say, bars of moist Ivory? Same reason.

Also, there is also free energy in space...particularly in a solar system. I'm not sure if light energy is believed to be particulate this week, but is it possible that photons or other forms of high frequenty energy could be used as a repuslive force? There's still quite a bit we don't understand about this stuff, and though at this point it's still probably the rhelm of science fiction, It's not impossible. Remember, there are no fictionless surfaces, no perfect vacuums, no perfect superconductors, only asymptoticly approaching approximations.

-Chris

PS - I apologize in advance for the above average number of typos and possible flaws in knowledge and logic....I'm on an iMac today ;-)

Re:Friction

[azaris]

There will be no TIE fighters until we have friction in space.

True, but some of the more "realistic" space-combat games like I-War had a Newtonian flight model but included an autopilot function that would both restrict your speed in relation to your target as well as strive to maintain your speed relative to your heading, mainly so that you were always heading towards your velocity vector. Of course one could override the autopilot at strategic moments to gain an advantage.

It was actually quite a believable hypothesis on what actual space combat would be like provided we still needed humans to pilot the craft at that point. B5 also used this idea.

Re: Friction

[rd4tech]

The mathemaician said: It won't be zero value, lets run few more pages of equations. The physicist said: We can safely assume it is orbiting zero value in this equation and thus reduce the next few pages. The engineer said: Screw it, it's zero. Lets build the damn thing.

Re:Friction

[Anonymous Coward]

Yes!

It always drove me crazy when I would see spacecraft *bank* in the movies. I know that's it's fantasy, and that a banked turn probably looks cooler than seeing a spaceship swivelling on just one axis to line up the main engines, but still.

Re:Friction

[gregfortune]

Just imagine swivelling (firing side thrusters) while firing the main engine. If you can swivel to line up the main engines, you can bank as well.

Re:Friction

[owlstead]

If only for the sound effects...

Re:Friction

[Adrenochrome]

In the novels that came after the movie, it was explained that this was accomplished by "Etheric Rudders."

Lame cop-out, I know.

Re: Friction

[Anonymous Coward]

I'm not sure if light energy is believed to be particulate this week, but is it possible that photons or other forms of high frequenty energy could be used as a repuslive force?

I don't know... your face is quite a repulsive force.

(Had to be done. You don't leave yourself open like that and get away without a broadside)

Re:Friction

[Anonymous Coward]

Just imagine swivelling (firing side thrusters) while firing the main engine. If you can swivel to line up the main engines, you can bank as well.

Sure, it *can* be done. Easily, I agree with you. There's no point to it, however, besides wasting fuel.

Re:Friction

[Pharmboy]

What if someone invented a 'Gravity reflector' that replys gravity? then you could us the gravity as the force your reacting to in order to move like an aircraft.

Except the TIE fighter would only be good if you were close enough to a large amount of matter. It would be worthless in a Cruiser away from large masses. Would again limit it to a base, and one with enough mass.

Re:Friction

[Theaetetus]

Wrong.

No... Grandparent meant banking like an airplane to turn. Not just "can you roll" but "can you turn by rolling to some angle, and pulling up - i.e. changing pitch".

Answer is no. In space, you accelerate in a direction in line with the force(s) you apply. You can roll very easily, you can pitch up or down, but you can't execute graceful 'airplane-like' (or TIE-fighter-like) curves as you turn without using a lot of fuel and many thrusters.

-T

Re:Friction

[David Gould]

What if someone invented a 'Gravity reflector'

Well, then they'd be able to make a perpetual motion machine / infinite energy source.

Silly DUPLICATES

[Yo Grark]

Although, Ion's second time around are just as fun!

Yo Grark
Canadian Bred with American Buttering...American Buttering....American Buttering...

We Like The Moon...

[Anonymous Coward]

We like the moon
Coz it is close to us
We like the moon
But not as much as a spoon
Cos that's more use for eating soup
And a fork isn't very useful for that
Unless it has got many vegetables
And then you might be better off with a chopstick

Unlike the moon
It is up in the sky
It's up there very high
But not as high as maybe
Dirigibles or zeppelins or light bulbs
And maybe clouds
And puffins also I think maybe they go quite high too
Maybe not as high as the moon
Coz the moon is very high

We like the moon
The moon is very useful everyone
Everybody like the moon
Because it light up the sky at night
And it lovely
And it makes the tide go
And we like it

But not as much as cheese
We really like cheese we like zeppelins
We really like them and we like kelp and we like moose
and we like deer and we like marmots
and we like all the fluffy animals
We really like the moon

Re:We Like The Moon...

[JoeShmoe950]

Insightfull ;-). I'm not shure if the mod read that 100%. It looks more Funny to me but whatever people like...

Re:We Like The Moon...

[Anonymous Coward]

Just more proof that the mods smoke them some real big crack rocks.

Build your own ion drive

[be-fan]

Check out this page for some nifty things you can build that may work on ion-propulsion. I thought it was a hoax at first, but my friend convinced me to build it in high-school, and the thing really did work. Of course, the efficiency was terrible. We were using an old monitor as a 20,000 volt power source, so power dissipation was probably pretty high. That was enough to lift the 2 gram device and 1 gram of payload.

Re:Build your own ion drive

[Anonymous Coward]

Lifters have been shown NOT to work in a vacuum... therefore these would not work for space. Even still, to lift off the ground requires more than 9.8m/s^2 which is a pretty respectable amount of thrust... which hopefully would indicate that ion propulsion isn't limited to 14 month+ missions.

Re:Build your own ion drive

[be-fan]

I think the way it works is that the top coil ionizes the air around it, while the bottom coil attracts the ionized air molecules. So the reason the lifter doesn't work in a vacuum is not that the mechanism doesn't work, but because there is no fuel to ionize.

Also, thrust (force) isn't the same as acceleration. Say you're getting 11 m/s^2 of acceleration in an upwards direction. For a 3 gram lifter, this equates to a thrust of only 0.033 newtons of force. That's only 0.0074 pounds of thrust, or about 1/7 the thrust of this ion drive.

Re:Build your own ion drive

[Anonymous Coward]

Biefeld-Brown lifters are not ion drives.

Army Research Labs:
arxiv.org/pdf/physics/0211001

Re:Build your own ion drive

[be-fan]

Thanks for the link. I never saw the Biefeld-Brown effect explained in detail. I knew it had something to do with ion-wind. Reading the literature, I have to say the two effects look pretty similar, except in the Biefeld-Brown lifter, the thrust is amplified by the movement of the fluid. Are there more substantial differences between the two effects?

Dupe or extreme interest

[sharkey]

Are we going to get daily news on this project?

Could such engines...

[Anonymous Coward]

...probe Uranus?

Re:Could such engines...

[Anonymous Coward]

On the inside, I'm running around screaming.

Re:Could such engines...

[Anonymous Coward]

i am presently enrolled in a 100-level astronomy class. you have *no* *clue* how quickly those so-called jokes wear out.

(it's pronounced with the stress on the first syllable, BTW. in a decent telescope - i've viewed it through a celestron 14, which has a primary mirror about a foot across - it looks like a greenish-blue speck, just barely large enough to tell it's not a pinpoint like the stars are, and the wrong color to be a star anyway.)

Finally!!

[WTFmonkey]

A chance to use this link

THIS POST WAS STOLEN

[Anonymous Coward]

this post was stolen from the last slashdot posting about this ion drive like a week or so ago!!

ONLY IF THEY'RE SHAPED LIKE A GREASED-UP YODA DOLL

[Anonymous Coward]

Lameness filter encountered. Post aborted! Reason: Your comment looks too much like ascii art.

Ion Propulsion?

[Ceadda]

This is just a cool way of saying they're driving the probe to the moon in the new saturn car. :)

your sig

[Hillman]

Dans cette place interdite. not interdit.

Re:your sig

[Anonymous Coward]

I would go as far as saying
"dans cet endroit interdit"
I highly doubt it would be a "place" (i.e., a square)

I'm not really interested...

[Anonymous Coward]

...until they say "First mare in space".

Finally...

[Anonymous Coward]

...we can expose the American moon landing SCAM! ;-)

Re:Finally...

[fucksl4shd0t]

...we can expose the American moon landing SCAM! ;-)

Aha! NOt after we expose the European Moon Mission Launch Scam, AND shoot down that fucking ship with our SDI that was actually built, in spite of the ridiculous claims of politicians and various sorts. That's what "build in secrecy" means!

TIE fighters?

[RyLaN]

so we get the lasers that make noise and move like they're nerf gun darts too?

Other science fiction reference...

[dpilot]

This one is more reputable, I believe credited to Arthur C. Clarke.

It was a short story about an Earth-to-Moon (orbit-to-orbit) space race, in the spirit of the Kremer prize. The spacecraft were propelled by ion engines, which were energized by Whimshurst-type machines, which were powered by ...

bicycles.

The racers pedaled their way to the moon, the pedals effectively powering the ion engines that drove them. The race took several days, with the right stuff added in for absurd athletics, rest breaks, minimal life-support, race security, etc.

No doubt someone here will do the math that I never bothered trying to do. One of these days, maybe I will.

Re:Other science fiction reference...

[beebware]

I was actually thinking of Arthur C. Clarke's "The Wind From The Sun" where there was an Earth orbit to Moon race with the "boats" powered by the pressure of the sun "but there's pressure - though you've never noticed it, because it's so tiny. Over the area of your hands, it comes to only about a millionth of an anounce. But out in space, even a pressure as small as that can be important, for it's acting all the time, hour after hour, day after day. Unlike rocket fuel, it's free and unlimited. If we want to, we can use it. We can build sails to catch the radiation blowing from the Sun".

Re:Other science fiction reference...

[agent provocateur]

How about if they were powered by balloons and polyester cardigans.

Re:Other science fiction reference...

[dpilot]

I think I read that one, too. But the bicycle/ion engine story seemed more appropriate to the topic.

Re:Other science fiction reference...

[swillden]

No doubt someone here will do the math that I never bothered trying to do.

I ran some numbers and the feasibility depends pretty much entirely on the weght of the spacecraft.

If we assume a 250,000 mile race, completed in 10 days, (with no resting, since that complicates things more than I want to deal with right now), that means you need a constant acceleration of 0.11 cm/s^2. Not very much, right? Not if you're just accelerating your own weight. In fact, if *all* you had to push was, say, 60kg, it'd be fairly easy. You'd have to generate about 20W of power, sustained, transforming about 1700 food Calories per day into thrust (assuming 25% efficiency).

However, you have to have all of your food, air and water, the spacecraft structure, engines and reaction mass. If all of that (plus your own body) masses 1000 kg, you'd have to sustain 334 W of energy output continuously for 10 days. It's extremely unlikely that any human could do that (even ignoring the non-sleeping issue). According to an article I found, maximum sustained human energy output is around 150-200 W. It also mentions that Bryan Allen, in his 1979 English Channel crossing in the Gossamer Albatross, managed to sustain ~250 W for 49 minutes, and it wiped him out.

Even a 500 kg gross vehicle weight requires a sustained output of 167 W. 300 kg would require 100 W, so you'd have to be somewhere in that range.

In practice, of course, these numbers are really messed up by the no-resting assumption, so it's really harder than they would show. On the other hand, in practice the vehicle mass would not be constant, it would decline as reaction mass and other consumables were ejected, which means you can get away with higher vehicle masses.

And, finally, these numbers don't even attempt to account for initial velocities or any kind of realistic trajectories.

Conclusion: Your guess is as good as mine!

Re:Other science fiction reference...

[Wiktor Kochanowski]

> maximum sustained human energy output is around
> 150-200 W.

In the exercise science (well, some coaches' approaches to it), maximum sustained human energy output is called "critical power".

Typical power outputs of, say, world class cyclists will be on the order of:

1500W for 10 seconds
800W for 1 minute
600W for 5 minutes
500W for an hour
400W for 3 hours ... and so on, 300W for 10 hours is not unsustainable for some like Johann Musseeuw.

> It also mentions that Bryan Allen, in
> his 1979 English Channel crossing in the
> Gossamer Albatross, managed to sustain ~250 W
> for 49 minutes, and it wiped him out.

He was dehydrated - didn't take enough water

Any barely competent cyclist should be able to manage 250W for an hour.

HTH

Re:Other science fiction reference...

[swillden]

300W for 10 hours is not unsustainable for some like Johann Musseeuw.

That's amazing.

He was dehydrated - didn't take enough water

That's an interesting issue for both pedal-powered flying and pedal-powered space travel... I don't know, but it wouldn't surprise me if Allen decided not to carry much water in order to keep the weight down. In the case of the race to the moon, the weight problem is more severe than for the Albatross. How much water does someone like Musseeuw consume during a 10-hour stint like that?

Assuming 1 liter per hour, you'd need to take at least 240 kg of water. More likely you'd have a system to recycle sweat and urine into drinking water. Probably need to divert a bit of power to that also.

All I can say is: Clarke has an amazing imagination.

Re:Other science fiction reference...

[Wiktor Kochanowski]

> I don't know, but it wouldn't surprise me
> if Allen decided not to carry much water in
> order to keep the weight down.

That was the case, precisely, as far as I can remember from watching a Discovery Channel program on the Gossamer Condor/Albatross.

> How much water does someone like Musseeuw
> consume during a 10-hour stint like that?

That depends mostly on air temperature and humidity, typically it's half a liter to a liter per hour.

This is something I will be keeping my Ion..

[adeyadey]

Sorry for that pun, but..

One point worth making - chemical rockets are getting close to the limits of thier possible efficiency. In contrast Ion engines are in their infancy. The main theoretic limit is that particles cannot be expelled faster than light. You could see very big leaps in engine power in the future..

Re:This is something I will be keeping my Ion..

[bo-eric]

In what way do you consider the fact that particles cannot be expelled faster than the speed of light a "limit"? As (almost) always when relativistic speeds are involved, think in terms of momenta instead of velocities... (the momentum of a particle is unbounded)

Re:This is something I will be keeping my Ion..

[MoP030]

it's a limit because the maximum velocity for a space craft is the velocity with which it ejects its fuel. Ion engines are faster than chemical engines because the xenon is highly accelerated. The acceleration of the ion propelled space craft is (currently) low, because the thrust of an engine is proportional to the mass of expelled fuel. When ion engines become mature, it will be possible to expel more ions and then you wont need to have a one year acceleration phase before the actual mission can start. So the fastest engine imaginable with current physics would be some giant lamp using photons as fuel. If you accelerate infinitely long you would get light speed. (Obviuosly you can never reach maximum velocity.)

Re:This is something I will be keeping my Ion..

[pdp11e]

"The main theoretic limit is that particles cannot be expelled faster than light"

This is not an efficiency limit. The energy and momentum are conserved. As propellant particles (ions) approach relativistic velocities, their mass increases so momentum still builds if one imparts more energy.

However, your main point is valid.

Re:This is something I will be keeping my Ion..

[AJWM]

it's a limit because the maximum velocity for a space craft is the velocity with which it ejects its fuel.

No, it isn't. You just have to carry more fuel if you want to exceed your exhaust velocity. This is basic physics. Review the rocket equation. Current rockets routinely exceed their exhaust velocity by several times. (NB - this applies to rockets carrying -- and hence accelerating -- their fuel. A scramjet has a problem with this -- which is why scramjets are really a silly idea for Earth-to-orbit propulsion.)

(Of course, this falls down at relativistic speeds, you aren't going to exceed an exhaust velocity of c no matter how much fuel you're carrying.)

Higher exhaust velocity means more momentum exchange per gram of propellant, which is the same as saying a higher specific impulse, which means a given mass of high speed propellant will result in greater delta-v than a low speed propellant.

Re:This is something I will be keeping my Ion..

[Anonymous Coward]

When ion engines become mature, it will be possible to expel more ions and then you wont need to have a one year acceleration phase before the actual mission can start.

The end result of your prediction is correct, but the mechanism behind it is incorrect. You don't want to expel more ions. You want to expel faster ions.

Sure, light speed is a barrier, but not the way you think it is. Those expelled ions will each have a mass approaching infinity the closer to lightspeed you get them. The only physical limits to the acceleration you can get from expelling these particles (even one at a time at extremely high relativistic speeds) are your own relativistic mass, the energy available to accelerate, and your willingness to travel at speeds that would result in your immediate atomization should you impact any signifigant matter.

Re:This is something I will be keeping my Ion..

[JollyFinn]

Here's a hint.
Energy source is limited.
E=MV
If we double the speed we quadruple the energy required. If we double the particles we only need to double the energy.

I think the reason why we never reach light speed in space travel is simple. Wan't to try design a collision detection for craft running AT light speed? Another point that we are right now traveling at light speed, yes the earth is currently running at light speed from a view point of a light that is emitted from earth. I don't think that the relativistic mass or atomization will be problems, because its always compared to what. [But i'm pretty sure that collisions at that speed are fatal.]

Re:This is something I will be keeping my Ion..

[MoP030]

You are right. With an exhaust velocity u and a rocket velocity of v, i was pretty certain the effective velocity would be like u + v. Doesn't make too much sense retrospectively as the rocket would be decelerated if the exhaust was slower than the rocket. Thanks for clearing that up.

Slowwww

[ewithrow]

Since it's taking 15 months to get there, that means that the thing is traveling at an average speed of 22 MPH.

They should have just launched my Buick Century to the moon and it would have gone faster...

Re:Slowwww

[Breakfast Pants]

yeah, if it travelled in a straight line.. its gonna be in orbits that keep expanding/contracting, etc. etc. etc. That saidm average velocity may be 22MPH towards the moon, but thats completely different than speed

Re:Slowwww

[SkankhodBeeblebrox]

Lets see your Buick make it to the moon on a tank of gas ;)

Ion Propulsion

[Listen Up]

I spent a lot of time studying this technology while I was working towards my Bachelor's Degree. Okay, let's get some facts straight, for those of you without a degree in Mathematics or Physics:

1) Ion Propulsion is NOT new technology. The Russians and German's have been experimenting with Ion Propulsion since the early 1950's. NASA is actually a late comer to the game, although the first with a completed ion propulsion engine.

2) Ion Propulsion do not work in an environment with an atmosphere. An ion engine does not have enough force to lift a sheet of paper more than a few inches.

3) An Ion Engine is very simple in design. For a simple explanation, an inert gas is ionized and injected into a chamber with an opening on one end. The opening has a magnetized torid ring around it. Using the right hand rule (make a fist, stick your thumb out like you are hitchhiking...your thumb is the direction of the electric current, your fingers are curled in the direction of magnetic field flow) you create an electrical flow around the metal torid ring. The resulting magnetic field 'pulls' the ions through the ring, resulting in propulsion.

4) The reason for slow inital acceleration is because the force of the ions passing through the ring is very small, but the velocity of the ions is very high. So, since there is no friction or other losses in space, after a period of time the velocity of the ions leaving the ring increases the velocity of the engine. After a matter of days the engine can be travelling at 10-30,000MPH.

For more information and history on Ion Propulsion engines you can go to the following websites:

http://science.nasa.gov/newhome/headlines/prop06 ap r99_2.htm

http://www.grc.nasa.gov/WWW/PAO/ds1.htm

http://space-power.grc.nasa.gov/ppo/projects/nst ar /

Re:Ion Propulsion

[Sparr0]

ion propulsion works just fine in an atmosphere, unless im misunderstanding the working of the popular 'Ionic Breeze' air filters.

Re:Ion Propulsion

[Grayraven]

It works, but an ion engine doesn't generate enough thrust to lift itself from the ground.

Re:Ion Propulsion

[Anonymous Coward]

Isn't that more of a gravity thing than a atmosphere thing?

Re:Ion Propulsion

[jd]

Two small notes:

First, this probe was from the European Space Agency, not NASA. NASA doesn't own Europe, as far as I know, and can't even afford to replace the bearings on the ancient platforms that carry the Space Shuttles to the launch pad.

Second, NASA's Ion engine (on Deep Space 1) failed in lab tests, and then failed in space. NASA had to "shake" the probe using the gas-based manoevering jets, using up valuable fuel. The probe was a success in the end, but more by luck than design.

Re:Ion Propulsion

[thue]

"An ion engine does not have enough force to lift a sheet of paper more than a few inches"

If it can lift it a few inches, then it can lift it to orbit with it's constant acceleration. What you mean to say is that it excerts the same force on a craft as a sheet of paper excerts on a table it is lying on.

"The reason for slow inital acceleration"

The acceleration is constant. The craft does, however, have a low initial speed.

Re:Ion Propulsion

[anubi]

"It works, but an ion engine doesn't generate enough thrust to lift itself from the ground."

Ehh... "lifters" ?

Apparantly they can develop enough thrust to levitate the engine itself in earth atmosphere against earth gravity - but I have yet to see one that could also hoist its own power supply along with it.

Re:Ion Propulsion

[brocheck]

Where-ever it is you live I imagine our glorious country is not far from demonstrating quite plainly where it is we've spent the money that was once sent to NASA for the foolish exploration of space (we already discovered there is no oil there). We may not have space-craft built in the last twenty years but what we do have speaks for itself: GPS guided smart-bombs, and a lot of them!

Don't worry, citizen, soon we'll liberate you too!

Re:Ion Propulsion

[Anonymous Coward]

"Okay, let's get some facts straight, for those of you without a degree in Mathematics or Physics"

I didn't realize that ion propulsion was a mathematical discipline. Is that like differential ion propultion? What is ion propultion ^2? Can you factor ion propulsion?

Re:Ion Propulsion

[MConlon]

Second, NASA's Ion engine (on Deep Space 1) failed in lab tests, and then failed in space. NASA had to "shake" the probe using the gas-based manoevering jets, using up valuable fuel. The probe was a success in the end, but more by luck than design.

They didn't shake it, they rotated it to point the ass end at the Sun to burn crud off the ionizing screen. After that it started just fine.

MJC

Re:Ion Propulsion

[Manhigh]

The opening has a magnetized torid ring around it. Using the right hand rule (make a fist, stick your thumb out like you are hitchhiking...your thumb is the direction of the electric current, your fingers are curled in the direction of magnetic field flow) you create an electrical flow around the metal torid ring. The resulting magnetic field 'pulls' the ions through the ring, resulting in propulsion.

Actually, what you describe there sounds like a Hall effect thruster. Not all ion drives are Hall thrusters.

DS1's ion engine used charged grids rather than a metal toroid to achieve the acceleration of the ions.

In addition to Hall effect thrusters and grid-based ion engines, there are also arcjets, resistojets, and the ever-sexy-but-a-few-years-off magneto-plasma-dynamic thrusters.

Re:Ion Propulsion

[Manhigh]

remember kids, always preview your post before submitting

Re:Ion Propulsion

[Anonymous Coward]

Okay, let's get some facts straight, for those of you without a degree in Mathematics or Physics:

I have a degree in mathematics and i knew only about half of those facts...

Re:Ion Propulsion

[Anonymous Coward]

2) Ion Propulsion do not work in an environment with an atmosphere. An ion engine does not have enough force to lift a sheet of paper more than a few inches.

You didn't do very well in your Newtonian Mechanics class, did you?

Re:Ion Propulsion

[Anonymous Coward]

That would be because the other half were WRONG.

Re:Ion Propulsion

[Anonymous Coward]

Ion propulsion was developed during WW2 by Ernst Stuhlinger, one of Werner von Braun's colleagues, in Germany. The first prototype of an ion propulsion engine was used 1992 for the european satellite 'Eureka'. The 'Artemis', launched 2001 and also developed in europe, had two ion propulion engines.

The NASA also used such an engine in 1998 for the 'Deep Space One'...

Re:Ion Propulsion

[Anonymous Coward]

Yes. Funny how things have come full circle. Sounds like the Chinese 'liberating' Tibet all over again.

Re:Ion Propulsion

[sharkey]

NASA's Ion engine (on Deep Space 1) failed in lab tests, and then failed in space

Well, that happens when you push the bounds of known science. I hear Deep Space 9 runs pretty well.

Re:Ion Propulsion

[Listen Up]

That fact came from NASA's website. Why don't you spend some time researching before opening your mouth and looking stupid. Or you must know more about Newtonian Physics than both I and multitudes of other Ph.D.'s.

Have a nice day, kid.

Re:Ion Propulsion

[Listen Up]

Sorry, Anonymous Coward, the facts are correct. Please, Anonymous Coward, go to college, learn Physics, and then come back here and post something intelligent.

Have a nice day, kid.

You haven't read Hitchiker's

[SharpFang]

...guide to the galaxy. Obviously this maneuver is very unnatural for all space vehicles, but it looks so cool rich people will surely want to have stuff that does that implemented in their spaceships. Just for showoff, no matter how inefficient and ridiculous that would seem :)

The dark spots,

[AchmedHabib]

We all know what hides in the dark spots that they wish to explore and that no picture of what is lurking in the darkness ever will make it back to earth.
So all we can do is wait for the message that they have lost contact with the spacecraft..
..I have not watched too many movies...

Deep Space 1

[minus_273]

I think NASA did this already with DS1 waay back in 1997 or 98

Tuesday is the important day

[ctid]

Tuesday is when the ion drive gets switched on for the first time.

Mod parodies up

[Anonymous Coward]

Please tell me, why did you bother to post this?

You don't even seem to have performed a cursory scan of the semi-informed posts on this article which would have told you an ion engine makes NO SENSE AT ALL as a 'manoeuvring thruster' or a 'backup', and I really hope you didn't read the original article then say this.

I'm sure this is a first step towards an entirely content free internet. Please begin all responses with the first line of this message. .beep.

Thats easy to answer.

[AmoebafromSweden]

Well! Duh!

Tie's are far off because they have TWO engines!

Twin Ion Engines!

Re:Thats easy to answer.

[Anonymous Coward]

What are the moderators smoking.

Hope this unfair moderator gets smoked in the metamoderation

Re:me?

[geekoid]

"Dark Sith" should that be moderated redundent? Or are there happy-go-lucky-smiley-face-Siths I'm unaware of?

heh.

Xenon sucks

[Waffle Iron]

It also talks about the low-cost technology being used and the charged xenon (ion) propulsion system.

I hate those self-important A-holes who have those xenon propulsion systems. It seems like every night that I go for a short trip in low earth orbit, at least one schmuck has to fly by with those damned things turned on. How am I supposed to see where I'm going when I'm being blinded by the obnoxious blue glare that they spew? If they're the only ones who can see anything, it's not making things any safer overall.

I swear, I'm going to start flashing these jokers with my laser range finder if they don't get more considerate and stop using those damned xenon units in congested orbits.

Re:Xenon sucks

[Anonymous Coward]

Tch, boy racers! Next they'll be fitting 20" bass bins inside satellites and putting little blue LEDs in the wash/wiper holes - evidently a drive to make science more cool for teenagers...

Re:Xenon sucks

[Anonymous Coward]

A laser range finder is the same thing as a frickin' targetting laser. That might attract the wrong kind of attention from the guy you paint with it.

Inertia

[Anonymous Coward]

The issue is one of inertia - as momentum is conserved, if you are banking a turn, something has to absorb the momentum difference.

Yes there's stuff there, but not enough to do any sharp cornering (no matter your efficiency).

With light pressure - yes, but VEEEEERY slowly - aka solar sailing. You wouldn't recognize it as a turn, watching it.

thoughts

[itzdandy]

if your '71 chevy truck is slow, you just put in a bigger engine right?! so how about a bigger ION drive. and a small nucleur reactor.

i suppose you do lose some efficiency by carrying your own fuel, but nuclear power is far more efficient than solar power right now.

with larger ION drives, or more small ION drives, and enough power from the reactor, this may be able to compete with a rocket engine for inter-solarsystem travel.

but then again, id rather have laser,mazer, or phaser cannons. I'll travel really really slowly if I have a really big gun!

--

another advantage would be less vibration during accelleration. Imageing sending a team to Alpha Centauri using standard rockets. They would have to burn for 3 solid months to accellerate and the same to decellerate. 3 months is a long time to be strapped to a chair.

this solves the lack of gravity problem as well. Just accellerate at a rate the would be near 1G or at some acceptable level of force, then spin the ship around and do the same thing for decelleration. This way you would have artificial gravity for a good portion of the trip. I can't imagine the side effects of a couple of years is zero G, and what happens when the team trys to go to the plannet with no muscles built up for planetside life.

Alpha Centauri is something like 5,644,944,000 kilometers away, this is most likely a 5-10 year trip. Yes, artificial gravity would be good.

Also, the waste material from the reactor could be used as the actualy propellant(maybee, IANORS(I am Not a Rocket Scientist) and then you wouldn't have to store it, you could just eject it out the back of the craft.

Re:thoughts

[ninthwave]

ok Alpha Centauri is a star system consists of Alpha Centauri A, Alpha Centauri B and Proxima Centauri, that appears as a single star to the naked eye. Of that system we are closest to Proxima Centauri not Alpha Centauri. The distance to Proxima Centauri is 4.36 light years.
In Kilometers this is:
41,220,846,106,794

So you calculation is a bit off in the time scale.
To reach it in 10 years you would have to be going roughly half the speed of light or 150,000,000 meters per second

Re:thoughts

[memmel2]

Think about how much mass and and the speed you need to throw it out to get 1 G acceleration. Plus you max out at twice the speed of the propellent. It aint that easy

Re:thoughts

[Anonymous Coward]

About your last statement. I don't think you can eject out the waste and gain additional speed without using some other form of energy to push the waste out.The return will be proportional. But, losing the additional waste will make pushing the rest of the rocket easier though.

Not the first time an ion engine has been used...

[thepacketmaster]

This isn't the first time an ion engine has been used in space. NASA's Deep Space 1 probe toured the solar system for over 3 years with an ion engine. This probe isn't very well known, since it was just a test bed. But in the end it made some history by performing the closest encounter ever with a comet.

Re:me?

[Anonymous Coward]

Overlord jokes aren't funny anymore. I guess you didn't get the memo.

Re:me?

[Suffering Bastard]

You obviously have never heard of The Happy Sith.

I hope you're right...

[plj]

...and actually that they'll never appear.

Fast space travelling is cool, but any kind of fighters are meant to be killing machines - I hope we'll never need to see anything like Star Wars in real life.

Besides, TIE fighter would only be the first step. claimed to be only for "defending the Homeworld". Sooner or later someone would build a Star Destroyer, too. And eventually something like Death Star.

Thinking this and the bloody history of humanity, it's best to hope that no other intelligent lifeforms will ever be found from space. Humans are known to be too hasty in loading their weapons.

Of course none of this is any kind of concern unless we're capable for inter-star travelling. That may take some time, yet...

Re:Make the Stupidity STOP!

[Anonymous Coward]

Um, what? I know those words you used, but they just didn't make any sense in that order. Weird...

this is great and all...

[Anonymous Coward]

...ion engines seem to be efficient and low weight, but instead gives a low speed. Isn't there a way to increase efficiency and speed without increasing weight?

Great

[borius]

Now all we need is to invent a way to project sound waves in space, then we can hold re-enactions of all the battles in Star Wars :)

TIE fighters?

[focitrixilous P]

Can TIE-fighters be far off?
Those things were terrible! they took a shot and a half to kill, no shields, no warheads. Wake me up when they launch TIE AdvancedX1 or TIE Defenders. Those are cool.

This is NOT the first ion engine in use

[Manhigh]

Deep space one and many communications satellites already use them.

They dont really make sense as backup as you have to have two completely separate systems to support them (propellant feed, power, etc). Thats a lot of mass for something that may be nothing more than backup.

They make perfect sense for unmanned missions. Theres typically no hurry to get where youre going, and the mass benefits are large.

They can be used on manned missions, the crew would simply rendezvous with the craft in high Earth orbit rather than being aboard for the entire escape spiral from Earth.

IIRC, those big panels

[porkchop_d_clown]

on the TIE fighters were solar panels - that's why the TIEs were "short range fighters".

Vulcans

[geronimo_jerry]

what's next? warp drive and the Vulcans visiting?

Just how fast is an ion engine?

[polyp2000]

I understand that ion engines have pretty slow acceleration, so how long is it going to take this thing to reach its destination? The moon is not really that far away in the whole scheme of things, would it not be quicker to use a conventional engine ?

Re:Just how fast is an ion engine?

[caouchouc]

It would be a lot faster to use a conventional rocket. The cost to launch this thing into orbit and get it to the moon is a quarter of the cost just to launch a shuttle into orbit, though.

The Moon again, finally!

[apsmith]

It should be noted that the world has sent only a tiny set of probes to the Moon in the last 30 years - and only one of them (Lunar Prospector) was a NASA mission. The other US mission (Clementine) was also a very small and inexpensive mission, so basically since Apollo ended our spending on actual lunar missions has been maybe 2% what we've spent on Mars. Does that make sense to anybody here?

NASA still seems very reluctant to send anything, but they are being forced to by a recent review of solar system priorities - also several private firms and a bunch of other countries seem to be getting in on the Moon mission act - see the mission list from the Moon Society.

TIE Fighters are FAR OFF!!!

[mesach]

Remember it was a LONG time ago, in a galaxy FAR FAR AWAY.

For the sake of physics

[Dan Farina]

It may help to think of any rocket-type (and ion, too) propulsion based system like this:

Basically, the center of mass of a fueled up rocket does not change. If you had a rocket at a dead stop and started a burn, you'd throw as much stuff behind you as your displacement was forward. Hence in a simplified 1D rocket model (which is actually pretty close to correct, diffusion is actually pretty minimal) your center of mass never moves.

Arguably, you could say this means that the entire rocket array (fuel and all) never actually moves: just spreads itself out, with the useful "stuff" at one end of the displacement.

Re:For the sake of physics

[Anonymous Coward]

Precisely. They're not rockets so much as they are hot gas ropes.

Re:For the sake of physics

[Anonymous Coward]

huh? You're saying that, according to physics, a rocket never goes anywhere? I'm no physicist, but I can sort of 'intuit' how you might say that over a short distance of initial thrust or something. How is this true beyond the reach of the actual exhaust, though?

If I put my hand behind a rocket, I could sure feel the thrust (and the heat)... but what about if I put my hand WAAY behind it? There is no thrust there, no force acting against my hand. The rocket is elsewhere; it has moved, and is moving in other places.

Re:For the sake of physics

[Koatdus]

The rocket part keeps going one way and the mass ejected out of the back keeps going the other way. So, if you consider both, the center of mass stays in the same place...(unless acted upon by an outside force such as the gravity of a planet).

Think of it as a seesaw. (those things kids love that are now too dangerous to put on playgrounds because their parents will sue someone).

If you send the same amount of mass out of the back as the mass of the rocket then for things to stay in balance they both will travel the same distance from the starting point in a given time. If you send a much smaller mass out of the back then the smaller mass has to travel much farther away from the starting point in a given time then the rocket part.

Finally since the center of mass of the entire system stays still, the smaller the mass going out of the back the farther away it has to be at any instant to balance how far away the rocket part is.

Re:me?

[Mesaeus]

Yes there are. They smile when they torture you.

IS THIS ANAL PROBE?

[Anonymous Coward]

JUST WONDERING.

You didn't see attack of the clones, did you?

[porkchop_d_clown]

Does the phrase "clone army" ring a bell?

Also, the books talk about Storm Troopers being grown instead of recruited.

Re:You didn't see attack of the clones, did you?

[Bobulusman]

Well, I never paid much attention to the books...

Still, just because there were clones during the founding the empire in AotC doesn't mean that all stormtroopers and TIE pilots in ANH were clones.

Re:You didn't see attack of the clones, did you?

[inertia187]

That's true, it doesn't mean that, but it sure implies it. And there doesn't seem to be any other evidence that counters it.

Then there's the phrase, "Aren't you a little short for a stormtrooper?"

Re:You didn't see attack of the clones, did you?

[Zarquon]

Actually, the books make it quite clear that most storm troopers are recruited in that time frame, and that after the clone wars practically all cloning technology is destroyed. (Note: Books are set after endor.)

In fact, I recall the 'Storm trooper training planet' getting blown up.. Jedi Academy trilogy?

Re:You didn't see attack of the clones, did you?

[Anonymous Coward]

That's true, it doesn't mean that, but it sure implies it. And there doesn't seem to be any other evidence that counters it.

Evidence? Like the fact that the clone wars ended and cloning was banned (people tried it in various books, and got themselves in big trouble if anyone found out). How about the fact that there were multiple references to imperial military academies and stormtrooper training right in episodes 4-6? Luke was supposed to go to one originally. He could have been cannon fodder rather than a lightsabre-wielding badass.

Then there's the phrase, "Aren't you a little short for a stormtrooper?"

There are height requirements for becoming a police officer in my district. They certainly don't all look like clones...

Re:You didn't see attack of the clones, did you?

[fucksl4shd0t]

Also, the books talk about Storm Troopers being grown instead of recruited.

The timeline goes something like this:

The Clone Wars is a very long war (or was, until Lucas came and started chronicling it) that was fought between clones and droids, and was therefore a HUGE waste of resources. The end of the Clone Wars saw the Galaxy essentially bankrupt, and laws were passed to outlaw cloning (and probably laws passed to outlaw droid armies).

Emperor Palpatine (this is a spoiler for anyone with half a brain that hasn't yet figured out that Chancellor Palpatine is the Emperor) stashed a few cloning tubes away (well, slightly more than a few) on his mountain. Grand Admiral Thrawn showed up 5 years after the Emperor was hideously betrayed and brutally murdered, digs out the cloning tubes, and grows a new army.

IN the Imperial interim, the clones died out after awhile and were replaced with regular recruits. Stormtroopers are essentially brainwashed to wash away all traces of individuality. First thing they lose is their name. After that, they are a number.

TIE Fighter pilots, on the other hand, are an aggressive and arrogant lot. In fact, Han Solo himself went to the Imperial Academy and trained as a TIE fighter pilot. He flew for awhile, then got kicked out of the navy when he rescued some wookie slave (Chewbacca) from the terrible crewelty of NIMH--er, the Empire.

Re:You didn't see attack of the clones, did you?

[Theranthrope]

The fuck they weren't!

Stormtroopers were conscripts, the clone wars were called the clone wars because they were fought with, you guessed it, clones!

Re:You didn't see attack of the clones, did you?

[Anonymous Coward]

Sorry to burst your bubble, but none of that is canonical. You said it yourself in the first sentence, "The Clone Wars is a very long war (or was, until Lucas came and started chronicling it)..." If Lucas wants to rewrite the storm troopers to be clones, he can. If that makes some of the back-story inconsistent, it's ok because it's just back-story. Fact is, the only story you can rely on is what comes out in the movies. Sure, the novels are authorized, but that doesn't make them canonical. Not sure where this convention started, but it's pretty common, not just to the Star Wars universe.

I remember reading that Boba was supposed to be a clone warrior who escaped. I also remember reading that Boba was just an average bounty hunter who found a clone suit and decided to wear it because he thought it was really cool. Looks like neither story ended up being canon. So get over it.

Re:You didn't see attack of the clones, did you?

[fucksl4shd0t]

Sorry to burst your bubble, but none of that is canonical. You said it yourself in the first sentence, "The Clone Wars is a very long war (or was, until Lucas came and started chronicling it)..." If Lucas wants to rewrite the storm troopers to be clones, he can. If that makes some of the back-story inconsistent, it's ok because it's just back-story. Fact is, the only story you can rely on is what comes out in the movies. Sure, the novels are authorized, but that doesn't make them canonical. Not sure where this convention started, but it's pretty common, not just to the Star Wars universe.

Yes, and no. The main problem is that Lucas doesn't care about any of that. You expect the stories in a universe written by a whole bunch of authors to contradict each other from time to time. But they all make a good attempt to be consistent. When contradictions occur, it's usually because the stories were written at the same time with no communication between the authors or an author wrote one story without even knowing another one existed that was pertinant.

I seem to recall that when Lucas authorized the stories he was going to accept them as canonical (as you put it). I'm not so certain people would have written so many of them if they thought it was just going to be thrown out whenever Lucas felt like it.

I remember reading that Boba was supposed to be a clone warrior who escaped. I also remember reading that Boba was just an average bounty hunter who found a clone suit and decided to wear it because he thought it was really cool. Looks like neither story ended up being canon. So get over it.

IN the books (and iirc the original Boba Fett action figure had a paragraph to this extent) Boba was born and raised in a "normal" family with a strong sense of justice and truth and so forth. As a Protector (cop) he killed someone that needed killing, although it was against the law, and was sentenced to death. I forget how he escaped, but he went and got Mandalorian body armor (the type of armor was stated during the first issue of action figures) and became a bounty hunter. He's a good guy in the sense that he fights for his own version of truth and justice and order. He's a bad guy in the sense that while he knows the Empire is evil, he thinks it's the best thing going for the galaxy, at the time.

But none if this is relevant any longer because Lucas decided to throw all that work away so he can make a few more bucks on another shitty movie.

Re:You didn't see attack of the clones, did you?

[Anonymous Coward]

But none if this is relevant any longer because Lucas decided to throw all that work away so he can make a few more bucks on another shitty movie.

You can choose to look at it that way, or you can choose to do what I do, albeit simplistic. Treat the other stories like you would if you really were in the Star Wars universe. That way, you can imagine they have fiction there that doesn't match up with reality, just like we do. And it doesn't detract much from the great story.

Like if a novel you're reading says that Chubaka has these massive claws for climbing trees, you might wonder why he doesn't use them in other situations. So the author of the novel says that it's bad form and dishonorable for a wookie to use his claws for anything other than climbing trees (not even to get out of a trap made by Ewoks). If you were reading this as a Star Wars universe citizen, you may or may not know it was fiction and move on. We, in our universe, have a bit of a challenge because we have never met a wookie.

Incidentally, these claws make me wonder how good of a midwife a wookie could be, or if the subject could or would come up in Episode III.

Then, keep in mind, it's all fiction. At the end of the day, you're no better of having read one version or another. It's all just entertainment.

Re:You didn't see attack of the clones, did you?

[fucksl4shd0t]

Then, keep in mind, it's all fiction. At the end of the day, you're no better of having read one version or another. It's all just entertainment.

There ya go. :) That's exactly what it is. There's no reason to be upset over inconsistencies, or even complete ignorance of a story. It's just not that big of a deal. :) (Naturally, I prefer to regard Lucas' latest creations as something to be endured more than enjoyed and have no trouble subtracting them from the Star Wars story at my convenience)

Re:You didn't see attack of the clones, did you?

[Anonymous Coward]

...I prefer to regard Lucas' latest creations as something to be endured more than enjoyed and have no trouble subtracting them from the Star Wars story at my convenience...

Your loss.

Re:You didn't see attack of the clones, did you?

[Anonymous Coward]

Actually, it makes sense, stormtroopers were the elite, many armies had (maybe have, I don't know) height minimums.

Re:You didn't see attack of the clones, did you?

[Anonymous Coward]

Also, in one of the books (I think one of those were there was a huge automated fleet and whatnot), when a stormtrooper or two are found dead they don't know what killed him... and they had been killed with a lightsaber (hey, the guy is cut in half, but maybe he died of a cold!). The books, even more than the movies, lack something that makes secondary universes good: internal coherence.

Deep Space 1

[barureddy]

You guys seem to be forgetting Deep Space 1. Deep Space 1 was launched by NASA on October 24, 1998 and uses ion engines. I'm not sure if they are the same type, but are xenon ion engines none the less.

On a side note Deep Space 1 had a cooler mission in actually navigating really close to an commet and taking pictures and running test.

Yeah, reeeeally sloooow Tie Fighters!

[blueworm]

From the article:

"Ion drives do not produce the sudden burst of forward momentum you get from a chemical rocket. But over the long-term they are considerably more efficient and many future probes will use them. "

Re:me?

[Dr. Photo]

"Dark Sith" should that be moderated redundent? Or are there happy-go-lucky-smiley-face-Siths I'm unaware of?

Yes. Be afraid.

Europe To The Moon?

[E-Rock-23]

The United States was quoted yesterday as saying "Been there, done that."

You all know what will happen when SMART-1 gets there: Brittain will claim it as a Commonwealth, the Germans will take it by force, France and Belgium will surrender.

Screw unmanned probes. We have the technology, and have for the last 30+ years. Let's send people back on a more permanent basis already. Just not Europeans. There's a reason why the word lunatic exists, and guess where it was coined...

Re:Europe To The Moon?

[agentforsythe]

does anyone have a spare "-1 jingoist nonsense" to apply?

So are ions more compact than conventional fuels?

[FatSean]

I mean, since the thrust is so weak, there must be a benefit somewhere, right? None of the articles touch on this that I've read.

TIE Fighters are FAR OUT!!!

[Anonymous Coward]

Man...

Didn't they say that about the internet?

[roninbix]

I remember a dilbert cartoon about people paying for fat pipes for much the same reason.

It will happen. You don't need friction, you just need ass-kicking "manouvering thrusters" on every side.

You can have your stupid tie fighters. I'm waiting for the xwing with "shields". Who the hell builds a space fighter and relies on non-regenerating "armour". Although, maybe I'd be up for the TIE++ model depending on how long shields take. You know, the one made out of carbon nanotubes with backup nanobot repair packs.

The ESA has this engine

[annisette]

and is using it, going to the moon. We have the blueprints and perhaps a model somewhere but... It would be a lot easier to praise or pummel their attempt if it was a race between ours and their's, five bucks to the winner. all I want to say is it is a great motivating day for space exploration and the best to anyone who continues space exploration in any way(peacefully). The direction the ESA is heading is what should be a priority, To The Moon, THE ULTIMATE ISS!!!

Free fuel.

[roninbix]

You can pull ions straight out of space. No need to bring your own fuel. Think of it like a submarine powered by water. That's also why they're good for long-term missions. Infinite fuel. You can just leave the pedal to the metal the whole trip. Granted, your acceleration sucks, but it doesn't stop.

Re:Free fuel.

[pe1chl]

I think this is not how it works, at least not today.
These engine systems take a tank of gas, then accellerate this gas using some ionosation device (like a spark) and get their thrust from that.
The only advantage is that they can get a high exhaust speed and thus a highly efficient conversion from mass into impulse.
(and part of the energy this uses is taken from the solar panels while the craft is underway, instead of being stored in the fuel all the time)

However, this is not an infinite source of thrust. Once the has tank is empty, it stops.

Deep Space 1 was no failure! with proof!

[UPAAntilles]

Deep Space 1 certainly did not fail (who in their right mind would send a multi-million dollar probe up without testing it first?!) Here's proof.

Deep Space 1 ion engine lab videos Pictures of the DS1 project (scroll down for ion engine)

DS1 was one of the most successful missions that NASA ever had. If you doubt me, you can look at the site...

Official DS1 site

They extended the mission MULTIPLE times, and even landed it on an asteroid (yes, landed, very softly too) This European mission isn't even worth mentioning. They're going to map the moon, whop-de-freaking do. The only reason it's getting press is because of the ion engine, which if the press cared about the American space program they would have reported that NASA has already succesfully untilized ion engine technology in space for hundreds of days in a row. It was shut down after hundreds of days of use (and after it had completed its mission). Then they restarted the engine (unprecedented!) by 'shaking it up' with the gas maneuvering jets. You've misread your space history, jd.

Re:Deep Space 1 was no failure! with proof!

[Anonymous Coward]

Sorry dear, forget about NASA, they never invented ANYTHING worth mentioning - ion propulsion is a German invention by Ernst Stuhlinger, from about 60 years ago. And the first ion propulsion engine was used 1992, for the european satelite 'Eureka'.
BTW, Ernst Stuhlinger was on Wernher Freiherr von Braun's Team, the one who invented rocket engines.

(Stupid?) questions

[Anonymous Coward]

If the ion propulsion spits out lots of positively charged ions. What happens to the surplus electrons ? Will the spacecraft build up a negative elecrical potential ? Will this cause trouble with discharges if you try to land on something when you get where you are heading ? Is there a way to dispose the electrons ?

Re:(Stupid?) questions

[MasterShake]

Most of the designs I have seen include an "electron injector" of some sort. Basicly, high voltage electrons are sent into the exhaust stream to maintain both the ship's and the exhaust's neutrality. (IIRC I stole "electron injector" from Scientific American)

Connection between hemorrhoids and space travel

[zooblethorpe]

Rockets move exactly in the same way an Ion propulsion engine would move. By forcing mass out the rear.

Man, if that was such a simple matter I'd be to Alpha Centauri after all the bean burritos I've had in my time...

--------
If I can own an idea, does that mean I can legally claim some portion of your soul once I tell you that idea? Or even if you just come up with it on your own? Heck, who needs contracts written in blood...

Long trip.

[Agent R]

The 15 month travel time isn't too appealing. But with the cheap cost and simpler propulsion system, the trade-off is acceptable.

The nifty thing is that ion drives is possible with practical applications for planetary exploration.

Re:Long trip.

[VanillaCoke420]

Exactly. What if they had ion engines on the Voyagers? They could have reached a speed much higher than now, with several decennia of acceleration.

Re:Long trip.

[Agent R]

I wouldn't put off the possibility of any Voyager-type missions in the future. It would of been practical if the Voyager spacecraft was outfitted with ion drives, but the technology simply wasn't there at the time.

Clarifications on Physical Laws

[peerogue]

The quantity of movement (m * s) is preserved in the system. "s" stands for the speed *vector*, and "m" for the mass.

Therefore, if you eject something out of the rocket, because the quantity of movement is preserved, you have a "delta s" generated that pushes you in the opposite direction.

Since rockets eject small quantity of material (compared to their mass), they need to eject it at a very high speed so that the rocket gains the opposite quantity of movement.

This is linked with acceleration (which is a variation of speed) but not really as you explained it: What matters is the ejection speed, which creates a delta speed in return.

If we assume the rocket's mass is M and the quantity of particles ejected at instant t is dm, at speed s, and we project the vectors on the propulsion axis, then we have:

0 = dm * s - (M - m) * ds -- Quantity of movement preserved, i.e. = 0

"ds" is the variation in speed of the rocket due to the ejection.

So: ds = (dm * s) / (M - dm)

The fastest "s" is, the higher ds, which is the acceleration gained.

Note that this is true only in space. An airplane ejects matters through its reactors continuously, but we are not in space: there is a reaction force exerced by the air within which the airplane moves. That's why airplanes tend to fly in the higher portions of the atmosphere, were there are less molecules (but still a sufficient supply of O2 molecules, since airplanes are not rockets: they don't embark the oxygen necessary for the combustion).

Ion engines

[reghall]

What is special about xenon? How much does one need to for a mission like this?

The crawlers were repaired a long time ago.

[Valdrax]

NASA [...] can't even afford to replace the bearings on the ancient platforms that carry the Space Shuttles to the launch pad.

Actually, they repaired and replaced the bad bearings in the JEL (jacking, equalization, and leveling) cylinders before they allowed Atlantis to launch within a month of discovering the problem during an effort to refurbish and maintain systems which hadn't been taken apart since the construction of the machines in 1966. That's pretty good considering that they only had 9 spares for 34 worn and broken bearings. They fixed it back in September of 2002 after discovering it in August of 2002.

How many...

[Anonymous Coward]

How many morons does it to answer a physics 101 question?

- well judging by number of replies to parent troll, apparently a lot!

Interesting or Risky?

[NetFu]

I know I've seen NASA projects testing a NASA Ion engine in space. I think it was Deep Space 1, which looks like it was started and finished years ago. They also made a flyby of a comet 2 years ago similar to this European probe's flyby of the moon. Seems to me that the moon is an easier target to fly by than a comet. So, this doesn't look like anything new to NASA.

Here's a FAQ on what they're doing with it and why most NASA projects don't want to use it:

NASA FAQ About Ion Propulsion

It could be simply a question of money -- if you can afford to use tried-and-true technologies, why use slower, riskier technologies when you really REALLY have to produce results? But, like they say in the FAQ, if they can prove the technology for long haul missions, that's where it makes sense. They even say specifically that for short missions like to the moon it doesn't make sense (look at how long it'll take that European probe to get to the moon -- 2005?).

Hmm, I don't remember seeing Deep Space 1 news like this on Slashdot -- I had to see it on PBS. Could it be bias or just ignorance? (correct me if I'm wrong, but even a search for "Deep Space 1" on Slashdot didn't produce anything relevent)

Sounds from space weapons

[Anonymous Coward]

The noises are from the EMP from the weapons and drive systems (Ion engines are famous for all the RFI they generate).

The changing of pitch in the pilot's voices when you changed scenes is because the Rebel Fleet was broke and used Single Sideband (SSB) radios instead of FM, which I'd have picked. I think they had FM after the Battle of Yar.

I still don't know what weapon, propulsion or whatever that made all them orchestra noises. Somebody told me that it was a "John Williams"; seems like a private joke or somethin'.

My own ship was scorched enough that I had to RTB early in the battle.

Last message from the ISS...

[Robo Dojo]

"Look, Houston. That SMART-1 probe is heading for the moon!"
"That's no moon..."

(Obligatory Star Wars quote)

US and Russian programs German in origin.

[expro]

Why would anyone mock the Europeans. In a very real sense, the US and Russian space programs are rooted in the very-successful German rocket program anyway, since the two superpowers divided up the German scientists after the war, forgiving any Nazi tendencies they may have had to form their respective programs.