Fighters in space

[HRogge]

The quality of missile sensors will be much worse than the sensors of a drone or fighter. In addition to this missiles have the disadvantage that they don't come back.

Why would missile sensors be worse? There's no technical reason they would be so. Missiles have the advantage they don't have to come back. Fighters have to burn once out to the target, once to stop, once to head back, once to stop. Missile burn once, out to target. (Ignoring mid-flight manoeuvres.

Missiles are smaller, so they can mount only small sensors ( especially important for optics ). In addition to this they are "throw away" weapons, so you will not mount sensors which are too expensive.

Think about it, would you mount the sensors of a hawkeye into a short range missile ?

[HRogge]

I can see other galaxies with the "naked eye"... okay, a good telescope is better, but I think passive EM detectors will be the best way to detect a spacecraft on long range...

Probably right. And the 'Can see galaxies' is actually the reason we won't be staying within visible range. Consider how far away the moon is, and how small it is. Now, try to imagine a carrier next to it. Keep in mind we can peg things with lasers at that range, at least for communications.

The hubble telecope could see the carrier ( especially the carriers engine trail ) easily. Do you think a radar system this small would be able to do the same ?

[SirNitram]

I can see other galaxies with the "naked eye"... okay, a good telescope is better, but I think passive EM detectors will be the best way to detect a spacecraft on long range...

Probably right. And the 'Can see galaxies' is actually the reason we won't be staying within visible range. Consider how far away the moon is, and how small it is. Now, try to imagine a carrier next to it. Keep in mind we can peg things with lasers at that range, at least for communications.

The hubble telecope could see the carrier ( especially the carriers engine trail ) easily. Do you think a radar system this small would be able to do the same ?

Not really. I suppose I need to clarify what Tharkun was claiming originally(And has since changed, seeing his ass was being beaten). Ranges will not be visible to the naked eye. The ranges the Hubble could see at would be more likely. Radar will fall out of use real damn quick, once it's used to lock onto you.

[Hotfoot]

I can see other galaxies with the "naked eye"... okay, a good telescope is better, but I think passive EM detectors will be the best way to detect a spacecraft on long range...

Probably right. And the 'Can see galaxies' is actually the reason we won't be staying within visible range. Consider how far away the moon is, and how small it is. Now, try to imagine a carrier next to it. Keep in mind we can peg things with lasers at that range, at least for communications.

Sure, you can see galaxies with the "naked eye", but galaxies are huge. We can see individual stars rather easily, but they're still considerably larger than a planet, and they're tossing out massive amounts of EM radiation. In comparison, how many planets can we see outside of our own solar system? By that, I mean how many planets do we have the ability to directly see with a purely optical telescope? None. The best we can do is say that, given the data we have, we can indirectly approximate the presence of a Jupiter-sized mass. Smaller planets like Earth are impossible given our current technology, and forget about moons and asteroids.

With passive detection, if it's not emitting or reflecting anything, you can't see it. Closer to a star, things get easier, since the star acts as a massive active sensor in that it is constantly pinging everything nearby with all manner of energy. This does give you the best of both worlds, after a fashion, but limiting yourself to just the Optical range of the EM spectrum does seriously limit your ability to detect things even within the solar system.

The hubble telecope could see the carrier ( especially the carriers engine trail ) easily. Do you think a radar system this small would be able to do the same ?

The Hubble Telescope is a darn good piece of hardware, don't get me wrong, and it could see the carrier, but only provided that it knew where to look, first. Depending on how much and what kind of EM radiation the carrier is emitting/reflecting, it will be easier to get a bead on it. This can be made more difficult by increasing the distance between the carrier and the telescope, and altering the EM output of the carrier in both emissions and potentially reflections. It would be tricky, but it is possible. In any event, even with all the equipment we have, sometimes things slip past us. I remember a case a short while ago in which a rather sizable asteroid travelling at a considerable relative velocity to Earth (the exact numbers are very hazy, but I can always try to find them again), and it wasn't detected until it had already passed through Earth's orbit. It was marked as a "near miss", though in this case "near miss" has the same meaning as "rapid change" in geology.

Now, if you're actively looking for something using a full array of passive sensors, especially near a star, chances are good you'll find it, so long as you know what you're looking for.

[Hotfoot]

I can see other galaxies with the "naked eye"... okay, a good telescope is better, but I think passive EM detectors will be the best way to detect a spacecraft on long range...

Probably right. And the 'Can see galaxies' is actually the reason we won't be staying within visible range. Consider how far away the moon is, and how small it is. Now, try to imagine a carrier next to it. Keep in mind we can peg things with lasers at that range, at least for communications.

Sure, you can see galaxies with the "naked eye", but galaxies are huge. We can see individual stars rather easily, but they're still considerably larger than a planet, and they're tossing out massive amounts of EM radiation. In comparison, how many planets can we see outside of our own solar system? By that, I mean how many planets do we have the ability to directly see with a purely optical telescope? None. The best we can do is say that, given the data we have, we can indirectly approximate the presence of a Jupiter-sized mass. Smaller planets like Earth are impossible given our current technology, and forget about moons and asteroids.

With passive detection, if it's not emitting or reflecting anything, you can't see it. Closer to a star, things get easier, since the star acts as a massive active sensor in that it is constantly pinging everything nearby with all manner of energy. This does give you the best of both worlds, after a fashion, but limiting yourself to just the Optical range of the EM spectrum does seriously limit your ability to detect things even within the solar system.

The hubble telecope could see the carrier ( especially the carriers engine trail ) easily. Do you think a radar system this small would be able to do the same ?

The Hubble Telescope is a darn good piece of hardware, don't get me wrong, and it could see the carrier, but only provided that it knew where to look, first. Depending on how much and what kind of EM radiation the carrier is emitting/reflecting, it will be easier to get a bead on it. This can be made more difficult by increasing the distance between the carrier and the telescope, and altering the EM output of the carrier in both emissions and potentially reflections. It would be tricky, but it is possible. In any event, even with all the equipment we have, sometimes things slip past us. I remember a case a short while ago in which a rather sizable asteroid travelling at a considerable relative velocity to Earth (the exact numbers are very hazy, but I can always try to find them again), and it wasn't detected until it had already passed through Earth's orbit. It was marked as a "near miss", though in this case "near miss" has the same meaning as "rapid change" in geology.

Now, if you're actively looking for something using a full array of passive sensors, especially near a star, chances are good you'll find it, so long as you know what you're looking for.

[Hotfoot]

Bloody buggering double post.

[SWPIGWANG]

more efficient drives are useless, in spacecombat against missiles the acceleration is important, nothing else. Short range missiles will have a much higher acceleration than a drone, so they will just hit you if you don't shoot them down. As soon as you are inside the range of a missile you cannot outrun it because it has the higher acceleration.

What's the use of being faster within 10 minutes if the missile will hit you in three minutes ?

Burnout

nuff said

[SWPIGWANG]

Damn no edit makes hastily posts possible....

Anyway, greater fuel efficiency because dictating the engragement as in when, where and how.

[HRogge]

Sure, you can see galaxies with the "naked eye", but galaxies are huge. We can see individual stars rather easily, but they're still considerably larger than a planet, and they're tossing out massive amounts of EM radiation. In comparison, how many planets can we see outside of our own solar system? By that, I mean how many planets do we have the ability to directly see with a purely optical telescope? None. The best we can do is say that, given the data we have, we can indirectly approximate the presence of a Jupiter-sized mass. Smaller planets like Earth are impossible given our current technology, and forget about moons and asteroids.

It's possible to detect the shadow of a planet when it's in front of another star, even with planets in other solar systems. It has been done !

And you don't need to see something within another solar system, all we need is a detection system with a few lightminutes range...

If you look for the engine trails even lighthours might be possible as a detection range.

With passive detection, if it's not emitting or reflecting anything, you can't see it. Closer to a star, things get easier, since the star acts as a massive active sensor in that it is constantly pinging everything nearby with all manner of energy. This does give you the best of both worlds, after a fashion, but limiting yourself to just the Optical range of the EM spectrum does seriously limit your ability to detect things even within the solar system.

EVERYTHING is emitting radiation at all times. It's called heat ( for example. Or just reflection of sunlight. An IR telescope would detect a ship easily, especially if it use some kind of nuclear engine...

The Hubble Telescope is a darn good piece of hardware, don't get me wrong, and it could see the carrier, but only provided that it knew where to look, first. Depending on how much and what kind of EM radiation the carrier is emitting/reflecting, it will be easier to get a bead on it. This can be made more difficult by increasing the distance between the carrier and the telescope, and altering the EM output of the carrier in both emissions and potentially reflections. It would be tricky, but it is possible. In any event, even with all the equipment we have, sometimes things slip past us. I remember a case a short while ago in which a rather sizable asteroid travelling at a considerable relative velocity to Earth (the exact numbers are very hazy, but I can always try to find them again), and it wasn't detected until it had already passed through Earth's orbit. It was marked as a "near miss", though in this case "near miss" has the same meaning as "rapid change" in geology.

Nasa has enough resources to monitor a fraction of the sky we see. It's no miracle that they missed the asteroid, it's just statistics.

A military would build more passive detection arrays to have a 100% coverage of the sky.

Now, if you're actively looking for something using a full array of passive sensors, especially near a star, chances are good you'll find it, so long as you know what you're looking for.

Just look for something hotter than the background, search for engine trails and active sensor signals.

Passive sensor systems get better when they become larger, so the defender/carrier/ect. will have an advantage compared to small crafts.

[HRogge]

more efficient drives are useless, in spacecombat against missiles the acceleration is important, nothing else. Short range missiles will have a much higher acceleration than a drone, so they will just hit you if you don't shoot them down. As soon as you are inside the range of a missile you cannot outrun it because it has the higher acceleration.

What's the use of being faster within 10 minutes if the missile will hit you in three minutes ?

Burnout

perhaps you will read my posting ?

What do you do when you are INSIDE the missiles range ? Nothing, it has enough fuel to reach you and a much higher acceleration. Either you block it's sensors or you shoot it down... there is no outrunning something with a superior acceleration in space, it can do any vector change that you do, only faster !

[HRogge]

Damn no edit makes hastily posts possible....

Anyway, greater fuel efficiency because dictating the engragement as in when, where and how.

Ups, didn't saw this posting until I hit the "Submit" button...

Fuel efficiency does not count because another fighter ( with similar efficiency ) would carry the missile. And they would be only fired when you are inside the missiles powered range.

[Hotfoot]

It's possible to detect the shadow of a planet when it's in front of another star, even with planets in other solar systems. It has been done !

To my knowledge, it's only been done indirectly, through studying the gravity footprint of a very large planet, like Jupiter, which is essentially a failed star to begin with. Smaller planets, like Earth, are not possible to detect with current technology.

And you don't need to see something within another solar system, all we need is a detection system with a few lightminutes range...

If you look for the engine trails even lighthours might be possible as a detection range.

This is true, though this is assuming that you know what you're looking for and can differentiate it from other possible sources of EM radiation/reflection.

EVERYTHING is emitting radiation at all times. It's called heat ( for example. Or just reflection of sunlight. An IR telescope would detect a ship easily, especially if it use some kind of nuclear engine...

Yes, IR would have a much better chance of picking up a ship since the ship would have to have some sort of power supply. But while everything might be emitting EM radiation at all times, that doesn't mean that it's all significant or noticeable. The radiation might be so faint that detection outside of a certain distance becomes very difficult, and from any further out downright impossible.

Nasa has enough resources to monitor a fraction of the sky we see. It's no miracle that they missed the asteroid, it's just statistics.

Agreed.

A military would build more passive detection arrays to have a 100% coverage of the sky.

That would be a lot of extra sats up in orbit, to say nothing of the equipment on the ground.

Just look for something hotter than the background, search for engine trails and active sensor signals.

Engine trails only exist while the ship is accelerating. A ship coasting in space would not generate an engine trail, because it's not producing any thrust. Also, how would you tell the difference between, say, a comet and a ship?

Passive sensor systems get better when they become larger, so the defender/carrier/ect. will have an advantage compared to small crafts.

No argument here.

[ClaysGhost]

To my knowledge, it's only been done indirectly, through studying the gravity footprint of a very large planet, like Jupiter, which is essentially a failed star to begin with. Smaller planets, like Earth, are not possible to detect with current technology.

Although it is an indirect method, you can indeed detect planets when they transit their parent star. The drop in observed brightness is not large, but it is well within detection limits for modern equipment. The method requires that the planet orbits in the correct plane to pass in front of the star as seen from Earth, so it only detects a subset of planetary systems.

The radiation might be so faint that detection outside of a certain distance becomes very difficult, and from any further out downright impossible.

This is true, but detector area (which limits sensitivity) is cheap in space at sub-mm wavelengths. I think I calculated range at one point, although it may not have been posted here. It was significant, even for Tharkun's Amazing Flying Heatsink unless it had an excellent match with background conditions. Hundreds of thousands of kilometres was not out of the question, and if your fastest weapons travel at c, what care you about light-minute ranges?

Engine trails only exist while the ship is accelerating. A ship coasting in space would not generate an engine trail, because it's not producing any thrust. Also, how would you tell the difference between, say, a comet and a ship?

Yes, heat emitted from the ship itself is far more reliable.

Passive sensor systems get better when they become larger, so the defender/carrier/ect. will have an advantage compared to small crafts.

No argument here.

Definitely. Larger ships gain in both sensor resolution and sensitivity. The resolution gain is offset by being a larger target (unless you use sensor outriggers, or similar) but the gain in sensitivity is radical and unanswered by the smaller craft.