Spacescifi

How would it cause problems for the engine's direction of thrust? Main engine would not do the tumbling, RCS thrusters would.... which would also stop the tumble when necessary. And in real life would not the rotation of the crew compartment cause the rest of the vessel to counter spin? Just like would happen if you tried slinging objects by spinning them with tethers from a spaceship?

According to kerbiloid you only need 100-200 meters.... If I quote him correctly, to get 1g rotation without messing up a human's equilibrium (sense of balance so they can walk without falling). I know at a thousand meters you only need one rotation per minute (RPM), but at 100 or 200 meters I know it will be more than 1 RPM. So how would that look? A ship spinning fast like fan blades? A blur? Or more like a thrown rotating knife? Fast but not so fast you can't notice the rotation without having to focus on it. Tumbling VS Rolling for gravity: Which you choose really decides how the spaceship is built and where crew will live inside it. Tumbling: Crew would live in the frontal part of the spaceship, since when you tumble, g-force is felt at the farthest end under rotation, and the other end would have the engine and fuel tanks anyway so it's space is already taken up. The main advantage of tumbling is that you do not need a really big spaceship, you only need one that is at least 100-200 meters long to reap gravity from it. I can see a T-shaped cylindrical shape being quite useful for a tumbling spaceship, since the broadside frontal cylinder could have a rotating inner habitat cylinder in it which rotates and stops itself in the direction of the gravity coming from the tumbling, so that down is toward the nose of the ship. Such a shape would grant more room for the crew than if you only had a rocket or pure cylindrical shape, since the only space on the ship that would matter to the crew under tumbling rotation is anywhere inside near the nose. Tumbling for gravity is also arguably the easiest type of realistic gravity types if your vessel is an SSTO. Rolling: To roll and get the same gravity from 100-200 meters you would need tethers deployed at or near that length. The alternative is to build a spaceship 100-200 meters wide, which frankly would make reaching orbit with it a proper pain. Generally speaking, oblong shapes are more reasonable to reach oribit than fat ones because the less air resistance the easier it is to reach orbit in the first place. The main advantage of rolling is it can open up more space for gravity for the crew, yet such an internal structure would not favor SSTO's but rather pure orbiters.

It can make for great comedy if done right. I read an excerpt from an old TOS star trek book where klingons patrolling a sector with no action actually became excited when they saw an asteroid on sensors... it was so sad it was funny. Meanwhile the Klingon Captain's inner monologue was that it was an 'honor' being out there, since he was actually being sarcastic. When the Enterprise shows up the Klingons are delighted for the break in monotony.

You are absolutely right... I just have trouble thinking a manned or intelligent life race will really take to the stars in greater numbers without technology that is more fantastic like star trek. I mean really... if we stuck a warp drive on a spaceX starship that could go 1 LY per hour the only people going on that mission would be pros. Wjich frankly is not exciting unless they are in danger or hilarious with each other being cooped up for so long. But they could only go few places if not one anyway because of fuel expense. In other words... in real life, doing the star trek thing requires a proper star fleet... not a single orbiter with shuttles. You would need an entire fleet of orbiters to allow you to visit several locations with them.

The problem is that none of those solutions work well for going to unexplored or places lacking infrastructure. You cannot even do a star trek like setting. The second issue I have is that dedicated manned orbiters will sooner or later need replacement of components. Not designed to land means a fleet of second stage shuttles would be the way to fix problems. But again, this does not really allow the lone ship to warp into a solar system, explore, and warp out on the regular. At best it would all be pre-planned and after every mission they would be forced to either go all the way back to base or a find, mine, and process propellant from an asteroid, moon, or gas giant. Which also involves exhausting precious propellant so you had better be sure the fuel source is a good one beforehand. The why of space opera is a big deal... the goal is to transplant the concept of sea exploration to the stars. Real technologies are hardly capable of that without infrastructure in place already. A sailing ship could go anywhere so long it had food for the crew. Space is far harsher and travel times longer while physics put limits on spinning things up for gravity and getting to places in a more reasonable time on par with sailing ships Therefore making it up is necessary in that case.

Orion has it's merits, but it is hardly ideal for how I wanted to use it as an SSTO.

You are kind as are other moderators... I did not feel you were heavy handed. At this point I more or less feel that making up stuff in scifi is necessary unless one wants to make viewers suppose rocketry can do things far better than they actually do and without melting the engine. My current scifi drive in mind may be a bit overpowered, but it gets the job done. And no it's exhaust is not rocket exhaust, but rather high pressured synthesized light. Normal light is low pressure so it can barelly push anything. Not so with pressor rays. T3: Type 3. Means max acceleration at 3g or less for 3 hours. Other types go all the way up to T9. Most manned vessels use T3's as that is all you need for LEO and beyond. Missiles: Use T9's but there is a catch. Large vessels carry large generators that allow for the gradual release of acceleration of the drive over time. Missile drive generators are too small for that so instead they use all their drive's stored acceleration in a single pulse. In other words... 9 hours of 9g acceleration is shot out their nozzle in a single pulse. All missiles are two staged, as the T9 missile drive is the the first stage and the second is an ordinany chemical missile with RCS. Because of drive generator scaling issues, only large vessels and missiles use it. Small manned shuttlecraft do not use the drive and are something of a bygone era. Big ships just land and take off on their own. Obviously FTL/ways to shorten interplanetary trips also exist that do not rely on the drive discussed here.

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.