In my story, I need a spaceplane, that is, a shuttle which can fly in an atmosphere as well as in space. It needs to be able to land from space, and then take off and go to space without refuelling on the planet. Also, single stage to orbit is a must.

As far as I know, no current propulsion method is a good fit. The weight of the fuel required to get to space is too much to be able to land from space, and take off again without refuelling.

So I decided that humankind developed the X-Engine in between now and the first chapter of my story. I don't care much about how the X-Engine works. The answer "It works very well" is good enough. But I do want to know what it feels like to fly in such a space plane, and what other effects the (invention of the) X-Engine would have.

E.g. (1) what is it like to take off, fly and land in an X-Engine powered space craft? (2) what would the space craft look like? (3) where would the X-Engine be used, besides space craft? Airliners? Flying taxi?

As I said, I do not necessarily need an explanation of how the engine works, but answers should be consistent. Obviously, the engine needs a lot less fuel than existing engines, which sounds like a huge cost cut for airlines, so, if it is not used by airliners, tell me why.

  • 2
    $\begingroup$ You are asking us "how does it feel to be on a X?" without telling us if X is a bike, a Harley Davidson, a Mustang, a donkey or a rolling log. How do you expect us to give a sensible answer? $\endgroup$
    – L.Dutch
    Nov 8, 2019 at 22:28
  • $\begingroup$ The closest you can get is SpaceX and their Raptor engine. But that needs retanking in orbit. if the retanking is not an option then there is nothing that is suitable appart from fission or fussion rockets which are still science fiction. $\endgroup$
    – Slarty
    Nov 9, 2019 at 0:24
  • $\begingroup$ If there is no refueling on the ground, then is there a miles-long landing strip with properly-functioning beacons for the shuttles to line up upon? Is there a gantry crane for vertical-takeoff configurations? Or is this a shuttle for explorers - no spaceport at all? $\endgroup$
    – user535733
    Nov 9, 2019 at 1:40
  • $\begingroup$ @user535733: It is explorer-style. so, no landing strip. $\endgroup$
    – Alex
    Nov 10, 2019 at 15:24
  • $\begingroup$ @L.Dutch-ReinstateMonica: I was hoping that there is some reasoning along the lines of "If it has property A, it also has property B", e.g. No matter if it is a Harley or a bike, it travels fast and is used at night, so it will be equipped with a head light. $\endgroup$
    – Alex
    Nov 10, 2019 at 15:29

4 Answers 4


You need two things: a way to land without a prepared (long, very smooth) runway, and a way to return to space without refueling.

An antigravity (or reactionless) drive is the simplest way to manage both of these. Even if it uses a huge amount of power, as long as it scales up well enough to transport a fusion power plant, the ship can be as big as it needs to be. It doesn't have to go particularly fast, because it isn't dependent on either aerodynamic lift or orbital mechanics.

Now, that being said, don't forget the basic principle of reactionless drives: they make any ship, no matter how small or decrepit, into a world-killer missile.

One solution for this is to require the drive to have a reasonably nearby, planetary scale (or larger) mass to react against -- literally anti-gravity. Get far enough out in space, and your acceleration will drop to almost zero; such a drive, by itself, isn't sufficient for a starship, but if you have some other method to travel between stars, an antigravity drive will work very well for travel within a star system. It's even better if it can pull as well as push; still with the distance limitation, but one can pull and push against the star, any handy gas giants, etc. and, within limits, be able to "tack" like a sailing ship.


Depends on speed power etc...

If your ship makes a slow controlled final descent of 30 minutes to an hour from outer atmosphere (to avoid heating up in the atmosphere) and assuming that the atmosphere does not alter the way it works, your passengers would gradually feel heavier or lighter (depending on what gravity inducing devices you have on this ship and the relative gravity of the planet) until their weight feels just above or below what their actual planetary weight would be (depending on the relative gravity of the planet) at which point I would assume that the gravity devices would be turned off resulting in a small but noticeable final shift in gravity.
In this scenario (again assuming a slow ascent to space to avoid atmospheric friction) the effects would be the same but in reverse.

If your ship uses the current method of using atmospheric friction to slow down then it would depend on the other advancements in technology. You could say that thermal insulation, inertial dampening and shock absorptive materials have come so far as to reduce a planetary descent of a few minutes to some external noise and a bit of vibration, something akin to turbulence on a plane or you could say that the descent is actually pretty jarring, requiring everyone to be strapped in to various types of harness. Gravity here would equalize in an accelerated version of the above but people might not even notice it if the landing is so jarring.

In space it would be dependent on how good the engine actually is. If the engine were made so well that everything works perfectly there should be no noise and no vibration as nothing would be out of kilter, if it is more rough and ready the engine would make noises which would echo throughout a ship unless dampened by something and assuming a metallic hull the vibrations caused by the engine would be present all throughout the ship, again, unless dampened by something. Strain on the engine would take a similar course, if made well there would be no difference between flying at full speed in space and flying at half speed, if not then there would be vibration and noise.

The kind of engine you are thinking of sounds like a washer-dryer to me, a washing machine with a separate tumble dryer is better because each machine is made for its intended purpose but combining them puts unusual stresses on different components causing the life cycle of the machine to diminish.
I would suggest that while this engine is capable of both atmospheric and space flight that the preferred environment is space and that most advanced civilizations have something akin to space elevators. The atmospheric capabilities would be used only in times where there is no alternate means of getting to the ground. This would stop this particular engine from being used for anything other than space flight regularly. There could be another engine which is essentially an atmospheric engine that could be used for space travel which airliners and/or flying taxis could use but it would effectively be the reverse idea of this engine.

With regard to fuel technology etc. I would suggest that your civilization had a leap forwards in its energy storage technologies, allowing for massive amounts of power to be stored in rather small devices and that the engine generates its thrust from some electrical method, this way solar panels can allow for collection of energy whilst in transit. The only other way is that maybe whatever fuel the ship uses could be skimmed whilst orbiting a star or some kind of planet but the energy output of such a material would have to be enormous as the best description for our rockets I have heard goes something like this:

We put three men on top of some of the most explosive substances known to man, we point it upwards, light the fuse and see what happens.

So anything that provides enough fuel to get up and down without refueling needs to be much more powerful than what we have today, I would suggest that such a material is highly explosive (think the power of the sun in a can) but only under the right circumstances otherwise a civilization could wipe itself out with one small accident and wars could be won by just blowing up one small installation.

As for the look of the craft, it could be as varied as you like in the instance of a slow descent, it just needs to be strong enough to support its on weight in atmosphere and keep the atmosphere inside when in space.
In the instance of using the atmosphere to slow down, it would probably need to be aerodynamic in some way with the ability to become less so at will. If you want it to take off like a plane then it would need to be roughly plane shaped but maybe with the option of deploying some kind of flaps that connect the wings and rudder to increase aerodynamic drag and slow down the ship more efficiently during landing. If you want it to take off like a rocket then it would need to be roughly rocket shaped and maybe the front section can be pulled in towards the body, splaying out the nose to create kind of an umbrella effect with the nose, again, increasing surface area during landing.


Well, starting right off with the spaceship part. How will we propel this ship without using much fuel? Simple (not really though). What is the universe full of? That's right, dark matter!. So this engine will be working by intaking and then expulsioning dark matter for propulsion. How do we attract dark matter? Gravity. I think that you could have a sort of tube on both wings since the wings won't matter in space. About where the engine on a jet plane would be. Some sort of gravity-pulse device attracts dark matter, and then what? Radiation repulses it, so fill the rest of the tube with angled radiators, and shoot that dark matter out the back of the tube. Boom. Space engine. Now for the atmosphere part. I think it would be shaped a bit like a regular airliner, albeit smaller. They could have these engines on their rear wings as well. Now, since dark matter goes through most regular matter, you could have jet engine inside the engines as well. This would work to propel the craft in-atmosphere. There you go. Spaceplane complete. I think this works, and I sure hope it does. Have a nice day!


Slap a basic impulser engine on it that pushes off the fabric of space-time. This means you don't need a propellant, and the only fuel you ever need is for the reactor or powerplant.

The sci-fi "physics" principle behind an impulser is that it generates momentum with an equal and opposite ripple (wave) in space-time. Objects in the path of the wave will be pushed. Much more likely, when an impulser is used in deep space, the wave is so diluted by the time it reaches anything that the effects are negligible.

Impulser waves are similar in concept to gravity waves and travel at the speed of light.


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