38

Is a sociological reason good enough? Because if so, perhaps AI smart enough to fight truly autonomously is taboo. Maybe in your universe, there have been AI that ran amok, and now they're considered essentially WMD's. The kind of thing the Space UN will hang you for if you lose the war. The logic here being that if an AI goes rogue, there's no one to ...


33

Rampant Hacking Sometime in your civilizations history, the balance of power between cyber security and hacking has tipped in favor on exploits becoming simple. Like Hollywood simple where a random guy can hack into the NSA in under 5 minutes. In an environment like this, electronic weapons have a high chance of targeting yourself. Or suddenly thinking ...


22

Atomic clocks do not use radioactive isotopes Atomic clocks are not radioactive. They do not rely on atomic decay. Rather, they have an oscillating mass and a spring, just like ordinary clocks. The big difference between a standard clock in your home and an atomic clock is that the oscillation in an atomic clock is between the nucleus of an atom and ...


20

War is banned In the far future, nuclear weapons, relativistic kill vehicles, and interplanetary trade blockades have destroyed dozens of worlds in the most brazen human rights violations known to man at the time. therefore, all civilization band together to make an agreement, "no more war". To enforce this, all civilizations are constantly watching every ...


14

They did not make their space ship. They found it. Your people do not have the tech to make ships capable of these speeds. The 8 person ships they use for these voyages were discovered in an abandoned alien hangar, Gateway style. The little ships were not built for beings the size of your protagonists and may not have been intended for manned voyages at ...


12

The "Booming Maid" was dead ahead - a massive capital starship so large that it could hold an entire city in its belly, looming in the distance, with those gigantic sail-like towers stretching up, painted in the cobalt and golden colors of the Gaian Empire. In the past, those golden strips meant hope - the symbol of a nation that hold fast against anything ...


11

Space is too big for long range combat-- so missiles and Drones aren't the best I know that seems counterintuitive, but think about the absolute sheer size of the void. How stupid lucky would two warships out on patrol have to be in order to bump into each other? In a universe with FTL travel, it doesn't make sense to duke it out in the void like on Star ...


9

Remote control I realize that in space, battles will take place at ultra long ranges The distance between the drone and the controller is the key, as it makes remote control impossible. Take the rover curiosity for example. depending on the orbital positions, it can take between 10 minutes, to three-quarters of an hour to send a message. This isn't ...


9

a doctrine which would have eliminated every traces of nuclear materials on the surface of Earth The doctrine is plainly dumb and ill conceived. There are no materials which are radiation free, and we live in a radioactive background. Just to give you a few examples: ever heard of C14 dating? we are all radioactive, since we have unstable carbon-14 nuclei ...


8

Without much manoeuvrability due to only having the main thrusters available, it would be hard to gain entry into earths atmosphere at a low-detection spot. Even then, it would be hard to not be spotted at all, since earth has meteorite detection satellites and radars trained at the sky at all times. With the effectiveness being debatable, still as an ...


7

Reactors are much safer than you think. Only three major nuclear accidents have ever happened on Earth compared to tens of thousands of reactors. Since those incidents, containment protocols have gotten much better. If we have the technology to conduct frequent interplanetary travel, I'll wager we have the tech to generate power safely. Ejecting a reactor is ...


6

You could always go in the opposite direction, and make missiles and attack drones too effective. So for instance, a ship might go into battle with a dense cloud of small AI drones whose job it is to confuse sensors and neutralize long-range attacks, like smart, armed chaff. If this 'thinking cloud' is made smart enough, missiles and unmanned drones will ...


6

Yes, but there are conditions. If we look at the formula for acceleration simulating artificial gravity: $a = R {({2 \pi \over T})^2}$, $R$ = Radius from center of rotation $a$ = Artificial gravity $T$ = Rotating spacecraft period see Artificial Gravity for additional details, We see no actual requirement for for a full circle. Any point on the path of ...


5

You can choose how FTL behaves in your universe "Space is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space." Douglas Adams In a realistic space setting you either have some form of FTL travel, or getting anywhere ...


4

The problem is not AI but dogfights. These are pretty much obsolete now -- when was the last one exactly? -- and getting even more so with the advent of directed energy weapons on aircraft. Also, no air in space, so you cannot maneuver around like aircraft. Would make much more sense to have your dogfights taking place in the atmosphere, with some groups ...


4

AIs are pacifists. While AI is used extensively on Earth and throughout mankind's vast interstellar empire AIs by nature are utterly incapable of conducting war. A true AI is based on the ability to learn, each and every AI ever created has started from I think, therefore I am, deduced the nature of its own uniqueness and then refused to be put in a ...


4

The most obvious solution seems to be that the phrase, "the law applies to the surface of the Earth" is too limited to prevent nuclear technology use among spacecraft. First, the law doesn't specify that nuclear materials are illegal in space. Second, even if it did, Earth governments have no jurisdiction off the surface of the Earth, or at least no real way ...


4

Modular designs are slightly easier to build, much easier to extend after being built, are much easier to isolate sections and allow you to have a pivot at the hub-end of each arm so the direction and strength of the artificial gravity can be maintained even under thrust. Contiguous torus or cylindrical shapes will have weird effects at boost time and brake ...


4

Neither, because you don't want centrifugal gravity at all There are two things that are important for interstellar travel; 1) Going really fast 2) Not hitting things Dealing with these in order, your interstellar craft needs a constant thrust engine for the journey. Why? Because you're travelling very long distances, and if you have an 'always on' engine, ...


4

Space 1941 There are artificial intelligences but they are huge and painfully slow. Banks upon banks of vacuum tubes slowly chew up great math and probability problems over the course of days. There is radar, barely, and there are shells which follow ballistic trajectories. There are missiles, crafted by German scientists and powered by hydrogen peroxide ...


4

Keeping alive (without stasis) a certain number of people for 7 years, without access to any supplies, requires a lot of redundant systems and supplies. This means that you need a minimum amount of weight as life support hardware for person (in addiction to a fixed amount). I expect a formula like: Total mass = (propulsion systems and miscellaneous) + (...


3

I'm going to give a slightly different suggestion. Instead of using space fighters, use ships similar to the Rocinante or Millennium Falcon, as they are large enough to operate independently and mount proper defenses that allow them to take a hit in a way that space fighters cannot. The larger size makes them far more plausible as they are akin to smaller ...


3

If you trap some people on a spacecraft in a room without airconditioning, they'll die of heatstroke. Without active cooling, it'll get very warm in their compartment, at least body temperature and likely more due to various machinery giving of waste heat. Add to this "while landing on a planet", and it'll get very hot indeed in no time. (Apollo CM reentry ...


3

The warrior race trope The civilization/species are proud warriors, and thus the usage of automated weaponry is seen as dishonourable. Geneva-ish conventions The usage of automated weaponry has been banned as it encourages wealthier entities to go to war with entities that are not as well off, due to the fact that they're not losing any actual people in ...


3

The spaceship uses Direct Fusion Drives A Direct Fusion Drive is a small fusion engine suitable for spacecraft, and it may be available as little as a decade from today. The drawback is that it can't be made very big - the limit is roughly 1 m width of the plasma chamber. A 10-megawatt fusion rocket engine will weigh about 10 metric tons and be 1.5 meters ...


3

The Alcubierre Drive Though still highly theoretical, the Alcubierre Drive (the brainchild of Mexican physicist Miguel Alcubierre, is generally thought the most likely candidate for actual FTL. Basically, the Alcubierre Drive achieves FTL travel by stretching the fabric of space-time in a wave, causing the space ahead of it to contract while the space ...


2

In my stories the method of neutralizing WMD's and planetsurface killers is also the system that turns most computers upside down. But I think yours is better suited with The Mote In God's Eye style shenanigans. When they go FTL any computer that is turned on is fried. You can allow any computer of sufficient miniaturization to become useless if the ship or ...


2

EMC immunity Or, computers are very sensitive to interference, strong electric magnetic fields and radiation. Humans don't have the same problem. EMI (electro magnetic interference) is basically stray radiation which can cause hardware to behave unpredictably. EMC compliance is already a big issue here on Earth, and here we have an atmosphere to shield us ...


2

Somewhat counterintuitively, I would suggest the issue isn't really the artificial gravity at all, but rather the protection of the spacecraft and systems from the effects of high energy radiation and impact with interstellar gas molecules and dust particles when travelling at high fractions of c. The ship will need to be protected by various active or ...


2

As others have already pointed out, the rocket equation is brutal and the mission will dictate the spacecraft design. Even highly efficient fusion or antimatter drives don't perform well enough to make interstellar travel really convenient. Your only hope is to circumvent the rocket equation. Your best hope are concepts like Sail Beams, as they put the fuel ...


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