Spacescifi

So after considering that rockets can lift anything to orbit with enough thrust and scale, I still decided not to use them in my scifi work as it is space opera. Not necessarily war but definitely an adventure. Rockets lack reusability, and reusuable propulsion drives are what make space opera work. A fleet of staging rockets is an alternative along with electroplasma jets for air travel, but I did'nt want to go that route either. So I made up an almost tachyon rocket. I say almost because it is really photons, flying through a special gas medium that when ionized allows the light to travel at FTL speeds. The glass over the flashlight is specially made NOT to slow the light down to lightspeed as it passes through, but once the superluminal light passes through to the environment outside it instantly shifts back to lightspeed since the universe normally does not apparently permit FTL photons. The end result is a reusuable spaceship drive that can run on batteries or even a nuclear reactor. Since photons already produce thrust, but if you increased their speed dramatically then their thrust I imagine would also increase. Allowing for getting to orbit. Yet I did not want the drive to be capable of endless acceleration, so I figured a 60 minute charge that allows one to do 1g for an hour is sufficient. If one wanted to do 3g to help leave Earth for orbit that would give you a charge of 3g for 20 min, but it should'nt take that long (eight minutes about) . And if you wanted dangerous level accelerations you could do that too, but the charge would not last as long. For example, 10g would make you exhaust your charge in only 6 min. All these calculatons were based on the division of 60 based on the number of g's accelerated. So what I want to know is, did I get the math right? It is important because I need to know how much charge the ship has at any given time so I know what the ship can and cannot do. Thanks also for previous answers.

Wow. Although I still think you would need ridiculoulsly high energy levels on that gamma ray laser. In other words, I think more energy than Earth can provide. A few jupiter mass equivalents of gamma laser blasts would probably work. Come to think of it... I like both your continent propellant rocket idea and the corona mass ejection star rocket idea. These ideas are so basic in practice that virtually any scifi faction with starships capable of warp or FTL should be capable of these feats if they were willing to invest the time and resources to do so. I do not know of any good reason to move a planet other than to move it closer or farther from the sun or a doomsday weapon. Moving a planet is problematic since by the time you have moved it far enough by ejecting continents, you may have less gravity and may even lose the atmosphere needed for life. Moving a star definitely seems purely like a doomsday thing. Oh you wanna make war with me? I will cause CME'S and bring an ENTIRE sun into your solar system! Sure it may take a century or so (accelerating a star up to relativistic speeds will be anything but easy, but hey, the nearest star is only about 4 LY), but wow, that is some WMD on steroids. Thanks for the idea, I may use it in my own scifi work someday. I wonder if anyone has already? No stories I am aware of.... good ideas!

Wow. I assumed enough weight would render lift off impossible. But that is ONLY so without staging as staging makes you leave used rocket mass behind so the ship becomes ligjter as it ascends. The irony is that with big enough staged rockets and sufficient thrust, the earth itself could be moved!

According to Scott Manley, metallic hydrogen has a specific impulse of 1700 seconds. That is rocket scientist way of saying that such a rocket would go farther per pound of fuel used than our relatively quick exhausted chemical and solid booster rockets. Nonetheless, the tyranny of the to rocket equation will stiill effect any rocket no matter how powerful so long it cannot create it's own fuel. Say you want to launch a constitution class star trek starship onto orbit and it weighs 190,000 tons. Theoretically perhaps solid hydrogen staged booster rockets could do it, given how much thrust they give, but maybe even that is too much. What I want to know is, what is the upper mass ton limit that you can lift to orbit with pure metallic hydrogen, assuming you had engines that would'nt melt? Also what is the upper ton limit on what you can launch to orbit using pure fusion without a fission reaction, fission whether through nuclear pulse propulsion or nuclear saltwater rockets, or antimatter propulsion staging rockets? I believe antimatter will require the least staging for launching the enterprise to orbit, but the exhaust would be gamma ray and other radiation, and I am not sure how safe that would be for the planet. Pure metallic hydroge, being an uber chemical reaction, I do not think leaves radiation hazards in it's wake, just a really hot plume. Launch and starship service life: Although rocket staging is not often seen in visual scifi, it really is the most efficient way to lift heavy loads to orbit. You can lift more through staging than you can without it, no matter if you're using antimatter or not. So if your goal is to lift massive ground built starships into orbit, staging is the way to go. Landing is not ever going to happen unless the ship is light enough and has the fuel reserves to do so. In that sense, any thing you launch into space that massive is a resource you will not get back. Overtime I think the ship's radioactive protection would probably be defeated by cosmic rays, (unless you have 6 foot thick walls on your ship) meaning you would either have to retrofit it in orbit or retire it. Retiring it would be a massive waste of resources, unless you dissassembled it and shuttled it piece by piece back to the surface of a planet.

Any shape can be used, but optimal shaped spaceships are more likely to be used than not if engineers in verse care about expense and effort. Sphere: Best at holding air in. No pressure cracks that would occur if you had air pressure inside a blocky shaped ship. Really any streamlining is better than a hard edge when it comes to holding pressure. In that sense, spaceships are really like glorified balloons that house crew that need to live in the balloon. Saucer: It is good for spin gravity. Although you could also do the same with a spaceship shaped like the letter H. Only with a LONG bridge between the sides. Blocky: Pressure cracks at corners will stress hull sooner or later if you put air pressure within the blocky hull. If you ony put air pressure in spherical or cylinderal roons inside the blocky ship you avoid that problem. Thus blocky ships would be great for drones or robot ships that do not need air to breath and thus won't have lots of air inside. Cylinder: You get most of the benefits of the sphere plus it is better for bulk storage of plenty things. Inside the ship: Although the captain and chairs on the bridge is popular, spanning many imitators, it is is really a sub-optimal design. They could likely save the energy they put into gravity generators by simply accelerating up instead of sideways. I know weightlessness is bad, and for times the ship is not accelerating the saucer is optimal for centrifuge spinning for 1g. It would be cheaper even if gravity generators were possible, since anything we already have a. grasp of is not considered very advanced in a scifi setting and should be thus easier to come by if advanced tech like gravity generators are available. Ship purpose: What a spaceship is made to do also has a bearing on optimal designs. Astetoid mining ships, if they do any processing of their own, practically beg for a shape that will allow spin gravity. Since processing and refining ore is easier with gravity than without. For ships that are SSTO's, compact designs have less drag, but if fuel is not a concern because the setting has super tech propulsion, suboptimal designs would have other reasons for existing. Sure the ship creates more drag than it needs to, but if it has antigravity to fall up, then it could reach space in about 2 min just falling upward from earth at 1g. Which is a huge improvement. The ship would still need to use some other propulsion to maintain an orbit, but at least there would be little to no air resistance in LEO, thus increasing fuel efficiency of rockets. And that is if rockets are even used as a main source of sublight propulsion in a scifi setting. They certainly do not have to be, as the only limitations are the ones a writer imposes on their work and self. Personally, I love saucer spaceship design, because antigravity makes it at least practical, and while it may never be as optimal as a cylinder or a sphere for holding pressure, it is optimal for spin gravity at least.

Some form of translocation (moving space past your spaceship without accelerating it) is a useful tool for scifi. Yet I read one work where the warp/translocatio/hyperderive followed a ballistic course. And you would only drop out of warp once you were nearby another star. That means you would have to already have your momentum heading for the place you want to end up. Otherwise you would end flying at warp forever until your vessel runs out of power and is stuck in interstellar space. Inertia drift would matter for a ballistic course, depending on how efficient and how much thrust sublight engines provide, and how fast FTL is. One LY per hour is good, but dealing with hours of inertial drift after dropping out of warp is either solved with high thrust/high efficiency sublight engines OR using the translocation drive to get much closer to the planet of choice without acceleration. I thought it was an interesting concept as it brought back the danger of spaceflight in a setting that was very much space opera. I nearly adapted it for my own work, setting mass lock distances (where ship can drop out of hyperdrive) at whatever the raduis of the destination celestial body times light seconds max or less. So for our sun, you could drop out of warp about 4 light seconds away, which would still make it uncomfortably bright. From there it would take 15 min to spool up the drive to warp again, and then you could do a drop near earth. Since earth's diameter is much less than a light second, you could drop in one earth radius away. Yet I didnt use it since I wanted to justify scifi ship designs where acceleration pulls you back toward the wall. For that I needed ships that would NOT have to use constant acceleration to reach their destination. It is only a matter of 15 min between every jump. Weightlessness is not so bad for such a short time period. Thrust only really would be needed for space rendezvous or landing on planets. Otherwise, you really should have decks on a ship like an office building if you have to rely on constant acceleration to get close enough to your destination to try landing.