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Re: Space Warfare II - Stealth Reconsidered Your expert is wrong. http://upload.wikimedia.org/wikipedia/commons/1/11/Galactic_Cntr_full_cropped.jpg There's a ship in there somewhere. Find it for me. It could be hiding in the glare of one of the overexposed stars. This also illustrates the incorrect assumption that there is no terrain in space. That picture is full of terrain.

Re: Space Warfare II - Stealth Reconsidered Yes, it will find 25th magnitude stars and 1st magnitude stars at the same time. What it won't find is 25th magnitude stars sitting next to 1st magnitude stars at the same time.

Re: Space Warfare II - Stealth Reconsidered It can do 10 square degree shots or go down to 25th magnitude. Not both. See the above about blooming.

Re: Space Warfare II - Stealth Reconsidered A follow-up on the 4-hour sky scan and why it won't work. The number comes from the Atomic rocket web site and is calculated by assuming a single wide-angle lens is taking 30 second exposures of 100 square degrees at one time to pick up 12th magnitude signals. Except you won't get 12th magnitude signals. You'll get a whole bunch of overexposed lower magnitude images, washing out everything else on your plate. The longer your exposure, the narrower your field of view has to be. It's physically impossible to look for 12th magnitude stars in 100 square degree chunks of sky at a time. Looking for twelfth magnitude stars restricts your field of view to arc-minutes or even arc-seconds. Suddenly, your 4-hour sky scan has turned into a 4 year sky scan. And it gets even better. You have to take repeated pictures of the same portion of the sky, gradually narrowing down your field of view on the dark regions as you increase your exposure times. And if your 12th magnitude star is too close to a 4th magnitude star, you'll never spot it. Which is another reason why you need sensor platforms scattered about your solar system. You need to take photos of the same portion of the sky from different angles to prevent a ship from hiding its 12th magnitude drive exhaust in the light of a 4th magnitude star. Yes, I know you can do a spectral analysis on the 4th magnitude star and find out that it has some unusual doppler characteristics. But that means you're going to be doing more than just taking pictures. Increase your sky scan yet again. Moral: Stealth-proof detection systems are not trivial. Because, to quote 2001 (the novel) "My God, it's full of stars!"

Re: Space Warfare II - Stealth Reconsidered

Re: Space Warfare II - Stealth Reconsidered I did. It's a distinction without a difference. You're discussing levels of degrees, not the fundamental issue. Or one with early 21st century technology like Earth where it's not considered worth the effort. Or one where for political reasons one may not be deliberately put in place. Ivory towers have little or no resemblance to the real world. There are many reasons why a solar system may not have a 100% stealth-proof detection system in place, but still have significant space travel. Um, yeah, we've done complete sky scans, but not in 4 hours. The Astrographic Catalog was divided among 20 observatories in order to reduce the burden of the task and took years to complete. The current US Naval Observatory catalog is the result of 50 years' work, yet it is only assumed to cover the entire sky, and only has an 85% accuracy in identifying stellar from non-stellar objects. The spaceguard report says that it will take six 2.5 meter telescopes 10 YEARS to plot 90% of near-earth large asteroids. 10 years, and it doesn't even get all of them. Real-world examples always trump theoretical postulations. This detection system you toss about so casually is not going to be as trivial, even militarily, as you maintain it is. Synodic periods are routes. By definition. You said so in your last sentence, in direct contradiction to your first sentence. Ships with limited deltaV are constrained to porkchop plot routes. Torchships run shortest-time routes. Routes exist in space. The window where the pirate's orbit comes within range of the route ships moving between worlds must follow. No engine hovering required. A typical tactic would probably be something along the lines of setting up a hyperbolic orbit when nobody's around and then hoping someone shows up at the right time. If no one does, reset and try again. There are many possible scenarios where setups like this can exist. A slight adaptation of the current Somali pirate practices is just one example.

Re: Space Warfare II - Stealth Reconsidered Yep. But you forgot about this part: http://www.projectrho.com/rocket/rocket3x.html#xray You can make the configuration disposable and bomb-pumped to make the engineering problems much less challenging. I personally liked your phrase "still a ravening death beam at one light minute." Which, by the way, also gives me cover (due to lightspeed lag) to launch my weapon, get it to safe range and fire it off before my target sees what I'm doing.

Re: Space Warfare II - Stealth Reconsidered It's not modest, or they wouldn't be loathe to do it. You're contradicting yourself. Yes, if the world were strategically important enough to warrant it. Which point I made in my initial post. On strategically important worlds and systems, stealth is a no-go. Then why haven't we? Once again, your argument shows a disconnect from reality. I'm beginning to catch the whiff of agenda here. That's a question of tactics. And it's also why certain routes will be known as "pirate space" because they are areas where it's easy to set up the ambush. Ships will only go there when the potential reward outweighs the risk. Yep. That's why it won't work for every system. If you have interstellar trade going on, this again devolves to tactics. Yep. Again, this is tactics. You will basically have ambush windows of opportunity.

Re: Space Warfare II - Stealth Reconsidered Well, yeah, if you don't mind it taking a couple of decades for your killer weapon to hit. You can do anything in space cheaply if you're willing to let it take a really long time. I wasn't aware there was a mandatory orbit required to be considered an asteroid. For a recon mission, I come in on a hyperbolic orbit. All kinds of stuff in our solar system are on hyperbolic orbits. It's not suspicious in the least. If I'm a pirate, I pick my spot in advance and set up my ambush and wait for unsuspecting ships to come by. Like all stealth, you don't have undetectable carte blanche. But that's fine, because that's what drives plots. The point I'm making is that it is theoretically possible. Once you get the theory down, then you're into engineering details and tactics. And science fiction allows you to claim "they somehow figured it out," when it comes to engineering details, and your story plot gets to explore the tactics.

Re: Space Warfare II - Stealth Reconsidered Probably not. Physics limits the density of things like these. But regardless. Storing the data isn't the issue. Gathering the data and monitoring for changes is. That requires sensor platforms and monitoring stations and ships and logistics to back it up. It's a non-trivial investment of resources, even for a spacefaring society. I addressed this in my original post. This will not work in systems with good detection networks. Not all systems will have good detection networks because of the required investment of resources. We don't fly U-2 spy planes over every square inch of the planet and we don't re-task spy satellites just because. We only do it for areas of high strategic interest. Identically, interstellar governments of the future won't be putting military-quality detection grids throughout every star system; only those with sufficient commercial or strategic value. No they won't because they won't need to. Do you know how much energy it takes to nudge an asteroid? They don't need to track the rock, they'll spot the heat plume of the reaction drive needed to move it. Just like you can't move your ship without giving it away, no one can move an asteroid without giving themselves away. You don't need to spend a billion credits identifying and tracking every possible piece of dangerous rock. All you have to do is look for big mass moving heat blooms. So, again, in poorly charted solar systems, stealth is completely possible by simply mimicking the radiative cooling of a naturally rotating object in sunlight. It won't work for major military assaults, but it will for recon and ambushes.

Re: Space Warfare II - Stealth Reconsidered It's not a question of getting "lost" in anything. I'm not hiding. I'm pretending to be something I'm actually not. Just another rock. Space is full of them. Except for recon and ambushes in border systems with poor detection infrastructures. It was just an example pulled out of thin air to illustrate the point because I didn't want to figure out the absolute magnitude of a 50-meter long cylinder with an albedo of .03 at 3.5 AU. Besides, a million kilometers away is a nothing shot for a good laser. Laser range is primarily limited by lightspeed lag. And lightspeed lag is only an issue if you're doing evasive movement, and why would you be wasting propellant on evasive maneuvers if you don't know I'm there?

Re: Space Warfare II - Stealth Reconsidered Yes, my ship is picking up the same energy on the sunward side as everything else. On the darkside, it isn't picking up anything. It's radiating. Second point: of course my vessel isn't in equilibrium. It's heating up on the day side and cooling off on the dark side. No rotating body in sunlight is in thermal equilibrium in the strictest sense, so that was a poor word choice on my part. What I meant by thermal equilibrium is a repeating cycle of heating and cooling. The engineering challenge is making my ship radiate in a way that mimics a naturally cooling rotating body. And I'm rigged for silent running which means I'm running on 100 KW worth of fuel cells and am not pumping out gigawatts of waste heat.

Re: Space Warfare II - Stealth Reconsidered Stealth in space is possible, but only under certain special conditions. There are a couple of assumptions being made that result in the false idea that stealth in space is impossible. These same assumptions are made in the excellent Atomic Rocket web site. The first assumption is that space is empty. It isn't. It's mostly empty. But mostly empty is infinitely more crowded than completely empty. The second assumption is that the only hot object in an otherwise bitterly cold universe is your spaceship. This is also not true. Every object in a solar system is various shades of hot. So the issue isn't one of "my ship shows up like a beacon because it's hotter than space in an infinitely empty universe therefore there is no stealth," but rather: my ship is a teeny-tiny speck that may or may not be hotter than other teeny tiny specks in the area. First, dealing with the space is only mostly empty issue. Your detection system is going to have to have a complete, continually updated database with EVERY object in your solar system, and I mean every object. That means stuff in the oort cloud, too, so if a comet gets nudged, you can spot it instantly and send someone out to find out if it's a natural object or something more sinister. Remember those cometary fragments are hotter than background space, too, and their IR could be a ship rigged for silent running. This is a major investment in time and resources, which means only highly strategic or important systems are going to have that kind of detection infrastructure. Border systems and less important worlds aren't going to have it. That allows us stealth using the other false assumption: that your ship is the only hot object in the universe. The key, here, is to make your ship no hotter than any other object in thermal equilibrium at a similar distance from the sun. That's going to prevent you from firing up your main drive with its gigawatts or more of plume heat, but it will mask your normal ship operations, so, no, your crew doesn't have to shiver in the dark. The asteroid Eros has a dayside temperature of 373 Kelvins, way toastier than your ship crew needs to be comfortable and way, way, way above the bitter cold of space, and that's out in the asteroid belt. The night-side temperature is 250 degrees colder. Chilly for your crew but still pretty darned hot compared to space. That gives you nice, big window where you can radiate your waste heat. You simply radiate the heat cleverly as if you were a rotating body whose sunward side has now pointed starward and is radiating its stored heat. To the IR sensors throughout the system, you just look just like every other boring rock out there. And just to forestall the potential argument, the fact that your ship may be on a highly eccentric or even hyperbolic orbit is not in the least suspicious. It happens all the time. That's why it's so important to have a continuous LIVE database of EVERY object in the solar system and its current trajectory along with its IFF. So, basically, stealth in space isn't about hiding your ship from detection, but hiding it from identification. Stealth attacks on important or strategic systems with a massive detection grid in place won't work, but in less important systems, it might be possible, and it certainly allows for pirate attacks on unsuspecting vessels traveling through poorly charted solar systems. Imagine your surprise when that 18th magnitude object your ship's scanners identified as the heat signature of a small asteroid with a 14-hour rotation period just opened fire on you.