Spacescifi

Ok... I believe you. What if you tried a hybrid rocket SSTO utilizing the same technology of sprint mixed with hybrid rocket technology? https://en.m.wikipedia.org/wiki/Hybrid-propellant_rocket You may add airbreathing rocketry or even pulse detonation rocketry if it helps it SSTO any better... anything but project orion since that has been well discussed. I am throwing known tech against the metaphorical wall to see what may stick.

The arc reactor would have gave Stark burns as would th.e wire

I was thinking about classic belly lander space plane SSTOs and realized solid fuel similar to the sprint missile would be ideal. Space is at a premium on a manned SSTO so having solid fuel which takes up the least amount of payload space is ideal. Yes I know you cannot throttle solid fuel rocket engines and they will burn all their fuel. That is the plan. Reaching orbit: Take off a runway at high g acceleration (not 100g but definitely 10g) crew can be do liquid breathing to handke g-forces. Burn through the atmosphere until air plasma surrounds leading edge of the hull. Activate magnetohydrodynamic fields to deflect and use the air plasma as a source of thrust to cruise out of the atmosphere and into space. In space: Any SSTO would have planet use solid fuel sprint-like engines and space only engines that use chemical propellants. Conclusion: Who knows if it would work, but in scifi defense screens and shield fields can often deflect uber plasma and particle beams moving at a significant fraction of lightspeed. If they can deflect that... atmospheric frictional plasma can also be.

Nice scifi thread Sevenperforce, did not think you had it in you lol! Anyway you are not going to want hear me say it but I have to. WASTE HEAT. I reckon the ironman suit would need to at least be the size and weignt of Iron Monger to either not overheat Tony Stark or provide so much impulse that it breaks his joints on a single pulse. Still it is a cool idea, but one that I really think should be scaled up for a space plane or first stage rocket or SSTO.

Can that even be done to helium by man and tech or does it require a gas giant lol? EDIT: Interesting.... https://arstechnica.com/science/2018/12/researchers-find-super-solid-by-looking-at-a-normal-solid/

Why not just send up a bunch of cylinder shaped spacecraft as second stages while omitting the pointy noses? I am saying sending all of a spacecraft up at once in separate pieces via multiple stage booster launches simultanously while the second stage cylinders would connect in orbit to form a larger spacecraft. Makes docking with each other easier to for orbital construction? I understand it will add to drag on the way up, but if all your boosters are reusable then the propellant savings lost should not matter as propellant (methalox) is cheap anyway. Come to think of it, piece by piece orbital construction of an Orion would be ideal. Just send up in one go via multiple separate booster launches with separate pieces, then have all the pieces connect in orbit.

Reusable chemical first stage boosters COULD be used to lift the mass equivalent of a WWII battleship (like the Bismark) into orbit, but by that point I really think they reach the point of diminishing returns based on TWR. Chemical thrust is limited and once the weight becomes ridiculous I reckon you would see first stage boosters literally using up their boost propellant and using reserves to land mere feet from off the ground. You would probably see a massive disc of reusable rockets attached to one another with the massive battleship load heavy spacecraft in the center of it all. What am saying is there is a breakeven point where using something more dramatic (*cough* external pulse propulsion) is more effective at getting high mass into orbit quickly and probably using less mass resources over all. I reckon to launch the mass of ANY project orion concept using only reusuable boosters would weigh much heavier than the orion project, which result in a very inefficient climb to orbit as rocjets drop off constantly even near the ground lol.

So perhaps Scott Manley was wrong (impossible lol)? He's only human.... I guess popularity and being right most of the time kinda makes it easy for people believe anything you say is right... when in reality it is better to be willing to never assume someone is right without verification... but people are often too lazy for that, especially when it is not a life or death matter. So the way things are shaping up on this thread, I am not sure there will be ever be a replacement for chemical and solid boosters as a first stage. Pulsed fusion is more doable than sustained fusion reactions, but given the complexity involved, it does not seem to make much sense to bother with a fusion anything type of rocket for a first stage. As far as I can tell, if you want to build a really powerful thrust fusion rocket you had better make it big, since the bigger you make it the more likely the reaction chamber won't explode when you ignite a pulsed fusion reaction. On top that you have radiation concerns. Simply stacking extra chemical rocket boosters that detach and land sounds a lot more sensible for a first stage and safer too.

Obviously a way to contain AM is needed, but how one transfers it to the reaction chamber without reacting with anything else along the way is the challenge. Like the only way I can think of is a vacuum chamber that rapidly opens to release AM that is shot into the reaction chamber where propellant is going. Which is honestly the main reason I am thinking pulse methods of propulsion. I mean if you could suspend AM particles magnetically in a pipe and funnel how more or less for thrust into a chemical reaction chamber I suppose that could work.. but again you would some type of vacuum otherwise the gases from the reaction chamber would enter the pipe and blow it it and the ship to smithereens. In space detonating fusion pellets work great with magnetic nozzles due to vacuum. But we do not have that luxury on a first stage rocket im atmosphere.

My Guess? Given how potent AM is I think you only need a single main engine nozzle but it had better be thick and sturdy (to stuff it with cooling apparatus tech). AM is volatile, so I think at best all one could do is send pellets containing AM into the reaction chamber... injecting more for more thrust, less for less. Still, to hold several grams worth of AM per pellet SAFELY would indicate a high level of AM safety manufacturing... likely AM neutral materials because otherwise you need uber magnetic fields and you can't have those reliably with small pellets. Suddenly the idea of a pulsed AM rocket stage sounds easier and safer... mainly because the flow of AM is not constant, you are only feeding discrete packages/pods of AM at a time. Am I right or wrong? Scott Manley said he thinks AM is more likely than fusion to replace chemical rocket staging to orbit. Fusion creates a lot of deadly neutrons which requires a lot of heavy shielding which makes spacecraft heavier than they should be to get off the ground. AM makes a lot of gamma rays which are easier to shield against with shielding not so heavy as would be required for excess neutrons. Even the ambient air would absorb gamma rays!

Is it not possible to make a laser beam out of concentrated sunlight via mirrors? If so, why not do that? Yeah I know... big mirrors, but at least you don't have to worry about power (it's the sun).

Hahaha.... yeah I know. The way I see it, it is far easier for many to pretend the pretty female face is their mate than actually try finding one IRL. But personally I just find it far too creepy. Occasionally you get funny ones though. I remember one about a Mexican girlfriend asmr waking up her cheating boyfriend. Video is VERY short.... since your POV is waking up with a very serious, bushy headed girlfriend staring at you with no makeup on, followed by a pillow shoved onto your POV until the video ends.

Honestly the only ones I ever watch are massage ones. Specifically anything with Steffi massaging from Mass Massage. Practically puts me to sleep. These I do not find strange. Yet I find the ones strange where people whisper talk really close to the camera. I have seen it and literally felt embarrassed myself AND for the person doing it. Obviously the content creator won't mind as they are getting paid, but I find it creepy. Like I am of the mind that hey... what's up with the whispers? And yes... I see a pretty female face. But can I stare at her whispering and crinkling paper for ten minutes or more? LOL no.

Getting stuff back down again (a fully loaded Orion) is not happening. It would take multiple shuttle orange giant boosters to land a huge orion or similar like sevenperforce said. So at best one could load an orion Spacex with starships as shuttlecraft. I suppose we could gradually disassemble an Orion in orbit to bring it back piece by piece via spacex launch but I digress. Orion is basically a semi-disposable massive cargo freighter to orbit.

Hahaha! So you are telling me that ultimately I was right all along! Project Orion is the most efficient way we can devise to launch heavy spacecraft to orbit. A pure fusion pulsed rocket would be better pf course because you don't have a huge explosion riding behind you every few seconds, but even with that and increasing the amount of fusion pellets that ignited it, you still won't have the thrust an Orion will have. If you are using more pellets to do what Orion can do with less, then you are losing on the fuel efficiency end and may as well just 2-stage it. There is nothing wrong with 2 staging, but I honestly think the the main problem with project orion as an SSTO is not launch but landing the thing. As you mentioned it would take several first stage large disposable boosters to even get it in the air. To land such a huge craft would require it to be huge and mostly chemical propellant tank and rocket nozzles anyway with s pusher plate and bomb assembly tacked on. So strangely enough now my thinking is... different. Launch small or lighter weight spacecraft to orbit using advanced more efficient pure fusion bombs with pusher plates. Since the spacecraft weigh less, the fact that the thrust may be less than a nuke may not matter so much. Since with less weight thrust increases anyway. And if worried for crew safety liquid breathing is possible, plus acceleration in pulses is very much survivable.

We could actually do pure fusion explosives according to the latest blog on Toughscifi by matterbeam. https://toughsf.blogspot.com/2022/03/fusion-without-fissiles-superbombs-and.html?m=1 It would be challenging to make it as powerful as a nuke, as examples he cited were less powerful, but given time and tech advancement there is no reason why such technology could not reach nuke level energies that I can see.

I can beat the firefly design.... without grav cancelers. A pair of flank rocket engines along the sides of the midsection. The shape I prefer for the ship is that of a letter T made with thick cylinders, with either the pusher plate or the nozzle at the tail end. For pitch control I would have some high thrust RCS under the belly of the frontal broadway cylinder near it's tips, and also some RCS above on the top. Lift off is obviously less hazardous to the environment witha pulsed pure fusion rocker than a pure fusion external propulsion system but the EPP is far easier as you need no uber magnetic field to channel the fusion plasma into the chemical reaction chamber. Also I honestly think you get a higher thrust with the EPP per pulse no matter what anyway. Simply because you can get away with fusion reactions so powerful that they would destroy a rocket's reaction chamber anyway.

As far as I know (very much feel to correct me if wrong), external pulse propulsion using pure fusion is far simpler to make compared to a pure fusion continous plume rocket, and pulsed pure fusion rocket would be midway difficulty between the two. Just how a continous fusion rocket would work is beyond me, since I am aware of the problems associated with trying to sustain a fusion reaction. It's hard. It is far easier to just get pulses of fusion and utilize that. Now how one does that with an SSTO is a bit of a process. You propose using small fusion pellets at a fast enough pulsed rate to make the ship fly like a continous plume. But how do intend to do that.... in atmosphere? Detonating a fusion reaction inside the throat of a nozzle seems like a bad idea, which is why I proposed using an inner magnetized vacuum chamber to focus the blast out the nozzle. The expansion will mainly be leaving the nozzle instead of all over. Trying to do this rapidly would make active cooling arguably harder. So ultimately my fascination with pulsed pure fusion is threefold 1. Safer than 'garden variety' nukes. 2. Fusion reactions can be both scaled below a nuke or scaled up to one. 3. Pulsed fusion is less complex than continous fusion reactions. I would also argue less maintenance too.

I see... so instead of a big heavy pusher plate we get s thick and heavy nozzle to handle the fusion pressure wave. It's quite interesting that at high power scales you MUST scale up the engine components or they WILL fail. Guess a pulsed fusion nozzle had better be large, heavy, and reinforced to handle the nuke level pressure waves. May as well add active cooling and ablative cooling from oil as well. We need the fusion plumes to be nearly as energetic as possible for propelling as heavy SSTO's as possible.

I was unaware fusion reactions could be scaled that far down. So basically I have one more question. Matterbeam's pure fusion idea called for pure fusion bombs. Could such bombs be used with chemical propellant if scaled down enough? I am envisioning a reaction chamber full of propellant, and mini-pure fusion bomb going off inside a magneticaly lined vacuum chamber behind it The idea would be to channel the fusion plasma blast to the propellant and out the nozzle. So I guess the real question is what is the max heat a nozzle can take because that decides how energetic our fusion reactions are allowed to be. I would like to think some tricks like coating the throat with thin layer of oil between pulses could prevent vaporization of the nozzle. Which is more or less the same trick the pusher plate employs but the who really knows until such is tested? I actually think a nozzle could survive a nuke level plume from a pure fusion plasma blast. According to nuke testing I read about, metal balls suspended in the air above ground zero for nuke testing were coated with thin layer of oil. And the balls were fine when found, even though they had been lauched far away. So apparently the oil coating thing works!

Pure fusion bombs would not produce the fallout nukes do... in theory it may even be possible to create small fusion bombs as powerful as nukes or less. Pure fusion does not even produce an EMP does it? It's the bomb a manned Orion deserves!

I think ground launch is totally possible. Yes you would lose the launch platform but that is all... the launch center itself would be farther away. My idea of an Orion belly lander with a rear pusher plate ship is T-shaped with a pusher plate at the tail end. I think using a disposable first stage series of rockets for initial launch is great idea. Yes the boosters would be huge but it's the price that has to be paid. The idea of a belly lander would work best for low gravity places like the moon and asteroids and comets. Returning to earth. Could be done with a bunch of second stage boosters sent to connect with the Orion in LEO before it does reentry maneuvers, the last of which would be reusuable since the ship would belly land with them. So in actuality, a heavy belly lander is not a an SSTO to anywhere, bit rather mostly to moons and preferably asteroids or comets with lots of ice. The main advantage one gains with pure fusion bombs is the ability to 'throttle down' the blast potential of the bomb. Which means you can in theory launch lighter weight orion vessels than possible with traditional fission triggered nukes. Which also means that onboard chemical rockets could lift it without the help of a disposable first stage array of rockets. Yet it all ends with optimization. A lighter orion belly lander that could VTOL with it's own chemical rockets would have slim margins for non-fuel payload compared to an orion that relied on disposable first stage rocketry. You can get more utility out of the second stage orion, at the expense of needing 'help' from ground control to ever return to an earth world. Any ship that is an SSTO however large is a glorified shuttle and nothing more. Anything extra makes it worse at it's job of shuttling. A large SSTO orion serving as a shuttle only needs seats for the crew and BARE minimum life support. Since the shuttle orion will link up with the second stage orion for crew transfer anyway in orbit. Then it can land using it's onboard rockets and remaining chemical propellant reserves.

Understood... this changes things for me. Alright... I am beginning to see a picture. Space only rockets for space, and chemical or air breathing rockets for air flight. By space only I mean mini-mag with fusion. I am going to have ditch some cherished scifi ideas and go places I never considered. Will be fun though. There is an awful lot you can do with modern tech if you can suspend the flow of gravity from effecting anywhere near your spacecraft before launch. Ha... you could even make zeppelins SSTO's so long they ride a grav-suspending rocket to space. And reusable chemical rockets would be popular for first staging as well. Chemical rockets with grav-suspension could save a lot of fuel, since all they have to do is burn and drift into space. Takes longer but there is no need to rush. What is an hour vs 8 minutes if you are saving tons upon tons of fuel?

Are you sure? Did not the designers intend the Orion to detonate bombs in atmosphere part way to space?

Alright feel free to correct me if I am wrong.... thanks for the info... you and everyone else. Why cannot a pure fusion Orion work in the atmosphere? The reasons I suspect you are going to say are: 1. While you could do it it would cause neutron activation and therefore radiation if the blast wave occurs near the ground. It's not a show stopper but does mean that you will have to watch the last of the first stage rocketds be blown to smithereens by the pure fusion blast. The first set of the first stage rockets could in theory be reusable and land on their own. You would need plenty of altitude to avoid neutron activation before you engage the orion drive. 2. Obviously landing an Orion is a no go... too heavy. Sure you could slow it down with pure fusion blasts, but the heat from the air I reckon would mess up the pistons over time since you are falling into inferno clouds again and again. Ironically.... the only way I can even see an Orion as a viable safe SSTO is if it could generate gravity suspension field bubbles around the ship. I know, I know, scifi super tech meets the obsolete, but it woumd still work. With gravity no longer in play making spacecraft get to space would be easy We could spin launch the thing and wait an hour for it to drift into space, and also spinlaunch a 100 meter radius habitat ring to attach with it in space as well.