Spacescifi

I see, so any more realistic SSTO will be smaller than any navy ship. More like a large airplane at best, which would require a type of fusion rocket anyway to reap such high thrust and efficiency with less fuel. Which means it coukd carry a little over 100 tons cargo like a 747. I think even if we had fusion, heavy lift SSTO's on the scale of project orion would not be practical. So SSTO's will always be glorified shuttles, designed for shuttling back and forth and little else. Rather than full on spaceships that do interplanetary trips too.

So I guess heavy payload SSTO's really are science fiction and will remain so since the energy required to VTOL them means that even of you did you are landing in lava walled craters. Canceling out the force of gravity would work, but that would break reality as we know it.... at least what we currently know.

I can accept that with rockets... inasmuch even Scott Manley admitted even if we had metallic hydrogen it would melt the rocket engine if we used pure metallic hydrogen. I had no intention of using a pusher plate for reentry shielding. My idea has been a T-shaped cylindral bodied SSTO vessel that is a belly lander with the pusher plate at the tail. During reentry it goes headfirst (the hammerhead front cylinder) which is fine since it has heat shielding on it. To slow for landing it would flip and ignite a few pure fusion bombs before going horizontal to engage rocket engines to slow for landing. But the way matters look it seems rocketry is a matter of go lightweight or stay home... if you want an SSTO anyway. Multi-staging is where rockets really do their best work If you want to heavy lift. Preferably reusable multistaging.

You can if it is a space-only ship. Vacuum is not a heat conductor like atmosphere.

1. Okay.... I thought there was neutron radiation involved? So it would be safe to watch the laumch from a several kilometers away outside then? 2. Flipping is necessary because the orion is a belly lander. It lifts off and lands with dual side resuable rocket boosters. I assumed chemical would be powerful enough to lift a heavy orion but apparently not without being really inefficient with payliad to propellant ratios. Besides the fact that hydralox would be a weak choice anyway. It is a belly lander because I prefer easier egress/getting on/off the ship once landed. Starship is a tail lander and must use a kind of elevator to get up and down. A belly lander only needs to let down a short ramp and crew can walk on out or ship cargo in or out as well. Also the fact that landing on your pusher plate like a tail lander means that lift off involves reusable rocket exhaust blowing past pistons... pistons you depend on to work that have flaming exhaust blowing all over them. It just seems like a great way to mess up the pistons. That is why I say belly lander. The original orion tail sitter was not designed to land at all and certainly not SSTO like a shuttle back and forth to a planet. Also as a belly lander it is easier to reach pistons for maintenanence. Lets say you land somewhere so cold the pistons freeze over? Yes I guess a tail sitter would be better in that instance since rocket exhaust would melt the ice. So maybe tail lander is better in that one scenario. Certainly not better at egress. 3. Sustained pure fusion reactions are difficult to contain because it is like trying to hold a star in a jar... if you did the heat would blow up jar. Stronger materials would melt before vaporizing. 4. What is Z-pinch? Because if is magnetic based SSTOing with it may... I say may be problematic because air conducts heat and magnets do not like excess heat or else they malfunction. Z-pinch may work great when already up in space, but I am discussing an SSTO capable heavy launch vessel on par with project orion for payload and mass. Are there any pure fusion pulse rockets that are on par with the abilites of project orion and it's ability to SSTO massive payloads? If not then project orion... especially with pure fusion is not exactly obsolete if you want a go anywhere and back kind of scifi SSTO that can carry heavy payloads. Even if pure fusion pulse rockers are scaled down it won't matter if their thrust lower and their fuel consumption is higher than project orion is with pure fusion bombs. EDIT: Likely pure fusion boosted chemical reusable rocketry would be needed for VTOL... while the rear pusher plate would use pure fusion bombs.

My thinking was that although pure fusion is far less toxic than fission nukes, it still is toxic. So I thought high explosive could save fuel gaining altitude while also reducing the radiation polution on the launch site. Turns out chemical rocketry would be best and then flipping to engage pure fusion orion. My thinking also was that a pure fusion orion is easier to build than an actual pure fusion rocket. Since instead of trying to contain a pure fusion reaction which is.... hard to say the least, it would most likely work by injecting pure fusion fuel into the reaction chamber and igniting it. Less powerful than a pure fusion orion reaction which is so energetic you would either need a giant reaction chamber or risk blowing it up outright.

This is a hybrid... high explosives are merely to gain some altitude without buring VTOL rocket propellant. Pure fusion bombs are at least theoretically possible and there are various ways of making them... from HE mixed with strong electromagnetic fields to initate pure fusion in fusion fuel, to using small amounts of antimatter as a catalyst for pure fusion reactions. It's not a show stopper from a scifi perspective at least.

Scenario: SSTO project orion vessel capable of VTOL via flanking chemical rocket thrusters, then flipping in midair and using rear pusher plate blasts from HE explosives to get some distance from the ground before switching to pure fusion explosives to reach orbit. Refueling the flank chemical rocket boosters: Obviously they need to be refueled or the ship cannot slow to land again. Most Likely Space Fuel for boostersl: Ice is my guess, split into hydrogen and oxygen. Most likely sources: Asteroids or comets. Moons are harder because they require landing... unless a moon base exists. In which case I suppose it could spin launch a full tank into orbit for the orbiting orion to rendezvous with, refuel and let the near empty tank deorbit with pure fusion bombs of it's own blasting off it's own pusher plate, and land using belly thruster reserve fuel. Why Ice: Because LOX and LH are potent together and fairly common in space. Ice is also easier to turn liquid than other solids. Other fuels: Water ice is not the only ice in space, I reckon CO2 ice and others exist on other moons. Oxidizer is often necessary for chemical rockets though, so without liquid oxygen you can almost forget VTOL with chemical rocketry. Also LOX and LH exhaust are non-toxic to humans so that is an added bonus. It's not like we are messing around with fluorine. What do you think? I think an explorer ship based on the OP would not expect moon bases to exist where it is going. Instead I would expect a minimal crew and more machinery dedicated for processing ice into liquid rocket fuels, with different tanks for each type. Orion blasts would still push the vessel around the solar system, but chemical rocketry would be the means to land the ship safely anywhere. In fact I would expect optimization to factor in the most. So large crews would not exist except in the case of passenger liners that were taking people to a massive city in space (oneil cylinder) or for trips to and from Earth clone worlds. Humans are resource hogs, so if you optimize for them you are bound not to be optimized for other matters in space.

Which is why I can accept scifi conceits like 1g gravity flooring on spaceships. It's pure scifi apologetics really... as much as I like real science if you stick to it it constrains the stories you can tell. The alternative won't allow a large and well traveled manned presence in space anyway. For that to occur survival in space must be much easier than it currently is.

Clever.... I do not like being skeptical as I am an eternal optimist when it comes to space travel technology. Some issues with space travel are not reversible.... yet. Vision is notably worse... due to the excess pressure put on the eyes because of the swollen head. How a modified g-suit can or if it even could help that I do not know. I suspect that may cause other issues. I think the real elephant in the room here is one word.... ulcers. Bedsores are ulcers that happen on areas of the skin that are under pressure from lying in bed, sitting in a wheelchair, or wearing a cast for a prolonged time. Bedsores are also called pressure injuries, pressure sores, pressure ulcers, or decubitus ulcers. Bedsores can be a serious problem among frail older adults. Adding a g-suit to this I suspect would only add to the ulcer problem, because g-suits merely add pressure to certain parts of the body to prevent pooling elsewhere... and putting pressure on the head to make blood pool in the feet and legs implies wearing some kind of pressure helmet. Darth Vader much lol? This is longterm hibernation, so we are talking weeks and months of just lying still. EDIT: Mammal animals solved this already. Bed sores arise from continued pressure on an area of skin, causing restricted blood flow and leading to tissue damage due to lack of oxygen and nutrients. They are common in those confined to beds who are unable to move or reposition themselves, such as those with paralysis, long-term illness etc. Healthy animals undergoing hibernation move regularly in their sleep which prevents these problems occurring. For example, this study of brown bears (http://www.sciencemag.org/content/331/6019/906.abstract) found that: Animals changed position twice a day to once every 2 days, when they stood, occasionally groomed, and rearranged bedding material. Smaller mammals enter deeper hibernation, but while they might not perform 'conscious acts' such as grooming or standing, they still move around in their sleep which prevents these injuries. By comparison, gravity via rotation from a 100 meter long tether seems... far more achievable compared to space hibernation. Another thing I notice that is irreversible is what I like to call hangy throat syndrome. Look at any astronaut who has returned and spent several trips in space and I notice how their throats seem to stick out more. Man or woman it's the same. Healthy earthers do not have this I notice.

Would the lack of gravity still play havoc on the human body or would hibernation retard that? Instinctively I presume hibernation won't help much... bones will still atrophy as will muscle, and eyes will bulge against the sockets and the head will swell for lack of gravity.... right?

Hmmm... apparently if a human was genetically modified to hibernate then they could. https://interestingengineering.com/sci-fi-style-deep-space-hibernation-might-be-closer-than-we-thought Sounds like engineered 'Spacers' would be the optimal version of manned spaceflight. Trade offs no doubt, but humans clearly were never designed for space travel, so imagine how well a human genetically engineered for it to hibernate among other things would do.

Since space is so utterly huge and torchship rockets are uber hard to create, I wonder if cryogenics could yet be perfected for manned spaceflight? I have read that currently that if you freeze a human you cannot thaw them out and expect them to live because their cells well develop ice crystals which renders them... dead. Animals who hibernate have natural antifreeze in their bodies that we do not, so their cells do not freeze over. I was curious.... why not use sonic or ultrasonic technogies to vibrate the body to keep ice crystals from forming while using cryogenics to keep it at what would be freezing temperatures if not for the sonics? May not even work but who knows?

Missiles can maneuver so it is not useless. Essentially.... kind of? With rocket missile upgrades. War has been more or less the same anyway. It's just the arrows became a lot faster and also self guided.

Tethers in space will make size less an issue. Spin launch on earth is fighting atmosphere and gravity. Space won't have that problem. I think you are saying that spinning up the entire spacefraft is unavoidable. If that is so then perhaps it would ve vest used for moon bases as I suggested. Tethere are less bulky than spin launch although more fragile.

It dawned on me that tethering up a missile and spinning it for an hour at 1g would allow a spacecraft to launch it at ludicrous speeds that the missile could never achieve on it's own nearly as quickly (ion drive would take months/years lol). Since space combat IRL involves a lot of lead time anway.... if in space and not mere low orbit, I think spin launching from tethers could compete with and even outperform railguns and coilguns. Pros: Much higher end velocity of missile or projectile launched. Cons: Takes longer to reload and fire I also presume NOT spinning up the entire spacecraft in the opposite direction as the tether is spun will becone problematic. If this can be overcome without wasting a lot fuel via thrusters let me know. I presume high mass could do it even though that makes the spacecraft a lumbering cow. Suggested prime uses: I think it is ideal for moon bases, both because they won't worry about counter spin and that they could install many for cheap but effective launching. Spaceships could also employ them if they have a lot of lead time.

Well yes... but if you ever wish to get the pad off the ground again that means rockets, and the way I see it, rocket exhaust plumes flying past the pistons I depend on to reach orbit is almost daring murphy's law to do it's thing. Especially if it is intended as a reusuable SSTO. Somehow my mind just went there... I assumed flying car=SSTO. It does not.... but I digress.

Hmmm.... you may be on to something.... have any connections with aerospace engineers who would be willing to test this out? Either that or it's ALL you, which is arguably harder. Using the air around in creative ways should make all the difference though. I never was much convinced anything other than project Orion could SSTO with a meaningful (40 tons cargo or more) payload. The problem with SSTO is twofold. 1. Reaching orbit without staging requires a LOT of energy expenditure. 2. Deorbiting will damage the hull on each go so much that I doubt you could do multiple reentries without major hull repair. In fact the only way to avoid fiery reentry is powered deobiting, which is also possible using project orion. Landing the monstrousity would require a significant amount of chemical propellant though, preferably on it's belly since landing on the plate is not advisable.

Have you seen a diagram of how railguns work? It involves literally two rails that the projectile is launched from from off what is called an armature (a metal piece that pushes the projectile as it is accelerated from the rails below). Basically we are talking friction. Lots of it. Do that again and again and you melt your rails. So if you have spare rails and the means to reprocess melted ones back to tip top shape, you can fire away and view rails as expended ammo lol... reprocess them at your leisure. Hopefully when not in a combat situation lol.

Not necessarily.... humans are there to make judgement calls or a the very least someone to cast blame upon in case something goes wrong. Imagine if the pilot's home city is at a risk of getting fined or bought out if he does something illegal while piloting the spaceship? Even if the pilot dies in flames aboard the vessel, now the company that owns the vessel can shift blame to the pilot's home town and cover some of the cost of the lost vessel by fining or buying parts of his hometown outright? Yes this is not exactly.... something some countries governments would be OK with, but in space fiction, any kind of policy you want can actually be a reality. As it is, real life is brimming with policies terrifyingly brutal by civilizations otherwise considered the epitome of a civilized society. For example, I tend to wonder if one of the reasons the British have such polite manners is because back in the day the opposite end of polite was what happened to William Wallace. Braveheart may as well be rated g, since if they really showed what actually happened, it probably could not be shown in a movie theater. By comparison fining or buying out parts of or an entire town or city in recompense for a pilot's recklessness leading up to possible if not complete destruction of a company spaceship is rather tame.

I think that is a more an exclamation than an actual question.... since the answer I am about to say you no doubt know even better than I. But what so ever, I will say it anyway. The genetics we are born with is kind of like playing the lottery. Some have healthier genetic lines than others, and that to some degree I was told in high school had to do the with the history of families going way back. Not anyone in the present's fault, you cannot go back and yell at your great, great, great, grandpa or grandpa to stop.... doing things that won't bode well for the gene pool in the future of their genetic lineage. And also sometimes even if one has good genetic lineage that should enable them to live to a ripe old age, they put very 'high mileage' on their body, leading it to break down (die) earlier than if they maintained it with regular 'oil changes' (exercise actually recycles your blood) and good 'fuel' (quality food).

A single pilot of a big spaceship is ideal since it minimizes life support while maximizing cargo payload. The second thing it does is that it.... kind of provides insurance if something goes wrong.... since human pilots are usually a bit more reasonable than stupid and stubborn AI. It is rightly assumed that human pilots have a sense of self preservation and want to complete the mission and go home.

Fast enough not to need gravity is standard fare in scifi.... but given how that opens up a can of worms (RKV=any spaceship capable of that) I find it makes space travel even less interesting from a fictional point of view. And I see about the gravity. 100 area meter inner habitats it is. One of the bonuses is even if ypu land a spaceship with it on the moon you can still enjoy stronger gravity thanks to inner habitat rotation.

5. Refueling depots are very much part of any rocket based space propulsion. How it is done matters most. I favor propellant farms on airless moons, that fill up tanks and spin launch them to orbit for the spaceship in orbit that needs it. Meanwhile the orbiting spaceship drops it's empty tank and deorbits it for moon shuttle retrival to refill it later for the next ship. Reusable interchangeable tanks for spaceships.... not a bad idea if they use the same propellant farms.

Scifi is fun and all, but given how much even we know about what space travel really entails, I kind of am annoyed at how.... easy it is in scifi. I mean I KNOW why. Money. Not a cartoon. Real actors. Blah, blah, blah. So here I wish to discuss at least two things I would love to see in scifi. The simple truth is that there is little in scifi land that CANNOT be simulated using real technology. And here we go for examples! 1. Artificial gravity: You do not need fantasy gravity manipulation. All you need is a vessel with a habitat area inside that is at least 30 meters wide, although 60 meters is preferable. Gravity by rotation of an inner cylinder habitat that is preferably 60 meters will do (30 if you wanna be a cheapskate). You likely won't get 1g for fear of dizziness, but some gravity is better than none and keeps the doctor away. 2. Spaceships.... at least manned, SHOULD be big. Why? Because you need a lot of space for life support and artificial gravity via rotation. The less you have the worse off you are as a human. This does not necessarily mean they must be as heavy as possible either, unless you want some type of project orion SSTO that must be heavy to avoid killing the crew with excess acceleration. 3. Space warships would have tiny crews if any. Why? Humans take up a lot of space when it comes to life support and food. And if a space warship requires REGULAR maintenence by flesh and blood crew, then frankly that is a handicapped space warship. Space travel is a lot of drifting, more drifting than thrusting. Doing nothing is not hard. Doing something is harder on a spaceship, and that is all crew ever do inside one. I would go so far as to say that a big space battleship only needs a crew of I dunno... four? The less crew the more space for weapons after all. Also the less the crew consumes and the more likely they can survive a batte since they can be better protected too. 4. Seriously... optimize! I saw a scifi short from DUST (The Beacon) wgere a large space freighter only a had a single pilot. And I thought that quite right. Why pay for more when it is a glorified 18 wheeler in space? Makes sense no? Thoughts are welcome. Space travel is it's own enemy. You hardly even need space war on top of that to show how dangerous it truly is.