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It looks like the Jupiter Icy Moon Orbiter (JIMO) will be powered by a nuclear fission reactor driving its ion engines. Launch is scheduled for 2011, though early concept drawings make it seem rather large for a single launch...

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About Fucking Time!!!

phongn wrote:It looks like the Jupiter Icy Moon Orbiter (JIMO) will be powered by a nuclear fission reactor driving its ion engines. Launch is scheduled for 2011, though early concept drawings make it seem rather large for a single launch...

I wonder if they're going to get it off the ground, especially when all the anti-nuke folks start screaming and hurtling feces.

They may turn on the reacter in space. So that if an accident occurs it would spread all over the atmosphere. But they may still bitch.

And yeah its a good idea.

GrandMasterTerwynn wrote:

phongn wrote:It looks like the Jupiter Icy Moon Orbiter (JIMO) will be powered by a nuclear fission reactor driving its ion engines. Launch is scheduled for 2011, though early concept drawings make it seem rather large for a single launch...

I wonder if they're going to get it off the ground, especially when all the anti-nuke folks start screaming and hurtling feces.

Maybe they will assemble the parts in space.

the only problem with this is that is a fucking ION drive. it will take longer to get to the destination then, say, a nuclear THERMAL rocket, instead of nuclear ELECTRIC propulsion.

Ion drives have ludicrusly poor acceleration rates. Wake me up when launch a probe with an Orion drive!

Tragic wrote:They may turn on the reacter in space. So that if an accident occurs it would spread all over the atmosphere. But they may still bitch.

And yeah its a good idea.

History is way ahead of you. Russia has placed active nuclear reactors into space countless times with its RORSAT. Generally at the end of each satellites life it was boosted into a very high orbit. However in 1979 one of the malfunctioned and crashed complete with is reactor core into Northern Canada. Northern Canada isn't a radioactive wasteland last time I checked, just a cold one.

kojikun wrote:the only problem with this is that is a fucking ION drive. it will take longer to get to the destination then, say, a nuclear THERMAL rocket, instead of nuclear ELECTRIC propulsion.

The proposed NERVA has a specific impulse of 825 seconds.
Boeing's 601HP has a specific impulse of 2568 seconds.
The thruster aboard Deep Space One had a specific impulse of 3000-3200 seconds.

Ion is much more efficient.

Col. Crackpot wrote:Ion drives have ludicrusly poor acceleration rates. Wake me up when launch a probe with an Orion drive!

Yes, lets fry every satellite in orbit when you light off the Orion drive.

phongn wrote: Yes, lets fry every satellite in orbit when you light off the Orion drive.

Couple military birds might be able to take it.

phongn wrote:

Col. Crackpot wrote:Ion drives have ludicrusly poor acceleration rates. Wake me up when launch a probe with an Orion drive!

Yes, lets fry every satellite in orbit when you light off the Orion drive.

i would hope it wouldn't be set off until it was a safe distance away. (booster rocket) Any ship with an orion drive would have to be fairly large to be practical i think. beacuse, again, it would need the ability to propel itself far enough away from orbit before engaging it's primary drive. Come on Phong, the prospect of riding a kiloton level shockwave doesn't do anything for you?

There's no reason to use Orion. We don't need to get somewhere that quick and just lifting the thing to a 'safe' distance would require a lot of booster capacity.

phongn wrote:There's no reason to use Orion. We don't need to get somewhere that quick and just lifting the thing to a 'safe' distance would require a lot of booster capacity.

Aww! But Orion is cool! *has an "I <heart> Orion" T-shirt*

Anyways, that's hyper omega cool news.

phongn wrote:The proposed NERVA has a specific impulse of 825 seconds. Boeing's 601HP has a specific impulse of 2568 seconds.
The thruster aboard Deep Space One had a specific impulse of 3000-3200 seconds.

Ion is much more efficient.

And also produces much less thrust. It may have an Isp of a few thousand seconds, but the force it produces is about the same as a piece of looseleaf paper! Nervas are far superior.

Orion drive!

The day we make something like the Messiah from Deep Impact is the day all those ecoterrorists shut up for good.

kojikun wrote:And also produces much less thrust. It may have an Isp of a few thousand seconds, but the force it produces is about the same as a piece of looseleaf paper! Nervas are far superior.

That's the point of ion. That low thrust over a few months duration will beat out that high-thrust NERVA engine that'll only last a few minutes.

NERVA was primarily designed as an upper stage booster, IIRC, not a method for long distance travel. It could shove something out of the gravity well but was not particularly well-suited for going from here to Jupiter.

Admiral Valdemar wrote:Orion drive!

The day we make something like the Messiah from Deep Impact is the day all those ecoterrorists shut up for good.

Either that, or the Michael from Footfall

Orion drives have their use, just not for what we're doing.

phongn wrote:That's the point of ion. That low thrust over a few months duration will beat out that high-thrust NERVA engine that'll only last a few minutes.

And it'll take considerably longer to get to the destination.

NERVA was primarily designed as an upper stage booster, IIRC, not a method for long distance travel. It could shove something out of the gravity well but was not particularly well-suited for going from here to Jupiter.

Theyre VERY good as long distance thrusters BECAUSE of what they do. For instance, 4 Nervas can push an asteroid to near earth orbit in 5 years. A HUGE ASTEROID in 5 years. No ion drive could do that ever.

I love NERVA.

kojikun wrote:

phongn wrote:That's the point of ion. That low thrust over a few months duration will beat out that high-thrust NERVA engine that'll only last a few minutes.

And it'll take considerably longer to get to the destination.

NERVA was primarily designed as an upper stage booster, IIRC, not a method for long distance travel. It could shove something out of the gravity well but was not particularly well-suited for going from here to Jupiter.

Theyre VERY good as long distance thrusters BECAUSE of what they do. For instance, 4 Nervas can push an asteroid to near earth orbit in 5 years. A HUGE ASTEROID in 5 years. No ion drive could do that ever.

You know, it'd be nice if you backed up your claims of how good NERVA's are at long distance travel. Some math would be nice. A paper or two would be better.

And yes, an ion engine could move an asteroid from the Belt to Earth in 5 years. It'd just have to be a big one.

SirNitram wrote:You know, it'd be nice if you backed up your claims of how good NERVA's are at long distance travel. Some math would be nice. A paper or two would be better.

I'll look for some stuff.

And yes, an ion engine could move an asteroid from the Belt to Earth in 5 years. It'd just have to be a big one.

After a point size becomes a major drawback. You'd need a voltage difference of millions of volts in a standard design. Tho it might be possible to use a particle accelerator type system.

SirNitram wrote:You know, it'd be nice if you backed up your claims of how good NERVA's are at long distance travel. Some math would be nice. A paper or two would be better.

Everything I've looked at indicates that NERVA is designed to short-duration (like minutes) burns to move something very heavy over a short distance. It's essentially an extra-powerful rocket, nothing more. There's no way you're storing enough hydrogen onboard to get long-duration burns like ion.

NERVA is not designed for long-distance actions. This is where ion shines - sure, it's thrust is equivilant to a piece of paper falling on my hand. But it's continuous thrust, and the turtle beats the hare. NERVA gets a nice head start, but ion catches up and surpasses it over any long distance.

And yes, an ion engine could move an asteroid from the Belt to Earth in 5 years. It'd just have to be a big one.

If you're moving rocks, you might as well install a pusher plate and put an Orion drive on it. It's useful for when you need high thrust and specific impulse.

kojikun wrote:After a point size becomes a major drawback. You'd need a voltage difference of millions of volts in a standard design. Tho it might be possible to use a particle accelerator type system.

You could possibly make an array of many ion drives rather than a huge one, fed by a nuclear reactor and some fuel tanks. Orion is better, though, for this application, as I noted to SirNitram.

phongn wrote:

SirNitram wrote:You know, it'd be nice if you backed up your claims of how good NERVA's are at long distance travel. Some math would be nice. A paper or two would be better.

Everything I've looked at indicates that NERVA is designed to short-duration (like minutes) burns to move something very heavy over a short distance. It's essentially an extra-powerful rocket, nothing more. There's no way you're storing enough hydrogen onboard to get long-duration burns like ion.

NERVA is not designed for long-distance actions. This is where ion shines - sure, it's thrust is equivilant to a piece of paper falling on my hand. But it's continuous thrust, and the turtle beats the hare. NERVA gets a nice head start, but ion catches up and surpasses it over any long distance.

That's what I've always heard, so I've been wondering if Koji went back for more of whatever he smoked during hte fighters-in-space and Singularity threads.

And yes, an ion engine could move an asteroid from the Belt to Earth in 5 years. It'd just have to be a big one.

If you're moving rocks, you might as well install a pusher plate and put an Orion drive on it. It's useful for when you need high thrust and specific impulse.

Quite. It's about the one situation where I'd advocate Orion.. Let's face it, it's been overhyped to hell.