Which proposed space technology do you find the most ridiculous/impossible?

[todofwar]

So these often come up, and I was wondering which tech people found to be the worst of the worst. I'm going with space elevator, because it's pretty much impossible. Then again, the EM drive is probably tied with it.

[kunok]

EM drive we don't have idea if it work and less how. So who knows

I'm already sure than a space elevator is absurd in earth, in other thread we talked that we only see sense (IIRC) in titan.

[magnemoe]

SSTO will come its matter of getting an good enough engine. Or some idiot pays for launching an falcon 9 stage without upper stage or payload
I put the Space cannon and Orion in the same category, it should work if we put lots of money into as it has downsides / limited use.
Space elevator, you need very strong materials not sure if possible, good chance LEO hold so much stuff by the time we could / wanted make it that it would be impractical.
Space fountain is most ridiculous as its an giant unstable system who would be very hard to run and by the time we could build it we probably have fusion powered ssto anyway. 
em drive is an wildcard, probably don't work. 
Don't know space loops if its that I think it is it run into much of the giant size project issus as space fountains but on the other hand much more practical and might have special uses. 

[todofwar]

5 minutes ago, magnemoe said:

SSTO will come its matter of getting an good enough engine. Or some idiot pays for launching an falcon 9 stage without upper stage or payload
I put the Space cannon and Orion in the same category, it should work if we put lots of money into as it has downsides / limited use.
Space elevator, you need very strong materials not sure if possible, good chance LEO hold so much stuff by the time we could / wanted make it that it would be impractical.
Space fountain is most ridiculous as its an giant unstable system who would be very hard to run and by the time we could build it we probably have fusion powered ssto anyway. 
em drive is an wildcard, probably don't work. 
Don't know space loops if its that I think it is it run into much of the giant size project issus as space fountains but on the other hand much more practical and might have special uses. 

Space loop is a giant magnetic track, launches things similar to a space cannon but over a much longer distance. Only works if your constantly launching things because the centripetal force of the launches keeps it up. 

[Scotius]

Orion drive. It makes just about as much sense as welding an anvil to the back of the car, and smashing it repeatedly with a wrecking ball to drive the car forward. Would it work? Theoretically...but there are less apocalyptic better ways to space travel.

[Wjolcz]

SSTOs are something that was built and worked perfectly fine with a good payload capacity.

 

 

 

 

 

Not on Earth though.

Edited September 29, 2016 by Veeltch

[todofwar]

10 minutes ago, Veeltch said:

SSTOs are something that was built and worked perfectly fine with a good payload capacity.

 

 

 

 

 

Not on Earth though.

I see what you did there. I think I should have specified earth based for the launch options in the poll.

[Nibb31]

Something is either impossible or possible. There can't be one thing more impossible than another thing. The question is ridiculous/impossible to answer.

[Bill Phil]

1 hour ago, Scotius said:

there aren't many better ways to space travel yet.

Fixed that for you. It's the best thing we've got that we can actually build, at least right now. Enormous thrust and high isp. Nothing comes close. And it's not nearly as apocalyptic as you would think. Variations on its design are everywhere, and we might just end up using some of them. Here's a pretty good link: http://www.projectrho.com/public_html/rocket/realdesigns2.php#id--Project_Orion

 

Most ridiculous? Probably the space fountain. A space elevator could be built on other bodies and would be more probable than on earth. Same with most of them. The EM Drive is downright impossible, but not ridiculous. Just impossible.

[todofwar]

20 minutes ago, Nibb31 said:

Something is either impossible or possible. There can't be one thing more impossible than another thing. The question is ridiculous/impossible to answer.

Something can be physically possible but practically not useful, like a space fountain or space cannon, or impossible, like a space elevator

Edit: and it's phrased as (most ridiculous) or (impossible), some people might think all of these are possible but some more ridiculous than others

Edited September 29, 2016 by todofwar

[mikegarrison]

http://www.smbc-comics.com/index.php?id=4035

[kerbiloid]

If this is not limited with Earth, space fountains are even easier than SSTOs.
There are numerous space fountains on Io and other celestial bodies. Just prepare a chute and wait for exhaust.
Yes, they don't work on schedule. But they are just stochastic aperiodic launch systems.

SSTO, Orion, space elevator and cannon are just a question of efforts and time. The latter pair are also a question of reasonability.

EMdrive - n/a. "Available data insufficient. Unable to compute." ("Aliens", Mother.)

Space loop. A particular case of space elevator.

So, nothing is impossible. A question of conditions.

[Frozen_Heart]

SSTO shouldn't even be on that list. Many modern launch vehicles could SSTO given just their first stage and no payload.

[monstah]

I was gonna go for Orion because it's just ridiculous. But then I saw the EM drive, and that's just a fabrication against the laws of physics, so yeah. That one.

[Nibb31]

Most of them aren't fundamentally impossible. Most of them are possible but highly impractical (space elevator, Orion drive, Cannon, SSTO,  Space fountain...), which makes them useless. The EM Drive is unproven technobabble at this stage, which can't be defined as possible or impossible since we don't know how it's supposed to work, or if it does.

The only one that is fundamentally impossible to build is the launch loop, since it involves a cable running in a 4000km-long sheath at 14km/s. The velocity of the cable keeps the loop at an altitude of 80km. It's impossible to build, because you cannot transition from 0 to 14km/s without going through a transitory state where the structure is unstable and collapses/breaks up/explodes.

[todofwar]

6 hours ago, Frozen_Heart said:

SSTO shouldn't even be on that list. Many modern launch vehicles could SSTO given just their first stage and no payload.

Note the poll itself said "used regularly". I am of the opinion (largely influenced by time on these forums) that SSTO just isn't practical on Earth. Staging is a great idea, and Elon has shown you can do reusable staging (eventually they'll get a reusable upper stage too). So, while it might not be impossible, I think it's just not a great idea for Earth based launches.

[magnemoe]

1 hour ago, Nibb31 said:

Most of them aren't fundamentally impossible. Most of them are possible but highly impractical (space elevator, Orion drive, Cannon, SSTO,  Space fountain...), which makes them useless. The EM Drive is unproven technobabble at this stage, which can't be defined as possible or impossible since we don't know how it's supposed to work, or if it does.

The only one that is fundamentally impossible to build is the launch loop, since it involves a cable running in a 4000km-long sheath at 14km/s. The velocity of the cable keeps the loop at an altitude of 80km. It's impossible to build, because you cannot transition from 0 to 14km/s without going through a transitory state where the structure is unstable and collapses/breaks up/explodes.

Space elevator need strong enough materials to be possible. Even then its probably impractical at least on Earth.
Orion, to justify it you need an giant ship or want to move gilly sized asteroids around, by the time this is relevant we probably has better engines. Space cannon could work for moving raw materials, you still have to pay for the shells and you need to collect them. 
By the time it would make sense we will have ssto. Might make sense launching stuff of the moon as you could launch cargo probes with an long horizontal track.

I put space fountains in the launch loop group. Mega structures who need constant power and control to not fail. You could theoretical lift the loop with rockets while it span up. 

From the comic list I nominates high attitude balloons as they do, space is fast not high so it don't give any benefits over being dropped from an airplane who is also questionable. 
 

[todofwar]

7 minutes ago, magnemoe said:

Space elevator need strong enough materials to be possible. Even then its probably impractical at least on Earth.
Orion, to justify it you need an giant ship or want to move gilly sized asteroids around, by the time this is relevant we probably has better engines. Space cannon could work for moving raw materials, you still have to pay for the shells and you need to collect them. 
By the time it would make sense we will have ssto. Might make sense launching stuff of the moon as you could launch cargo probes with an long horizontal track.

I put space fountains in the launch loop group. Mega structures who need constant power and control to not fail. You could theoretical lift the loop with rockets while it span up. 

From the comic list I nominates high attitude balloons as they do, space is fast not high so it don't give any benefits over being dropped from an airplane who is also questionable. 
 

But if we get engines that make ssto viable on earth, won't they still work better in a staged system? 

[magnemoe]

Just now, todofwar said:

But if we get engines that make ssto viable on earth, won't they still work better in a staged system? 

They would, it would probably also be used as so for heavy cargo but an SSTO would have faster turnover time making it practical for light and valuable cargo like people.
Putting up satellites in non standard orbit who are to high to reach from the ssto could be done with an reusable tug who returned to the ssto. 
Note that I see skylon as marginal as an ssto it main use would be staged. 

[Emperor of the Titan Squid]

I can see SSTO happening when there is a demand for rapid turnaround, and cheap space access. Space elavators are probably going to happen, as we develop cheaper way of making nanotube structures. Space fountains may very well happen, I don't see why not, although I don't know how advantageous they would be.Space loops, I have the same thing to say. I do expect space cannons to happen, although I doubt that they will take of, in the midst of othe launch systems. I am a believer in nuclear pulse propulsion, I believe we will see it in the 2050s, for exploring the outer planets, before we develop fusion. That leaves the Em drive, which doesn't make much sense overall.

[ModZero]

Really, including the EM drive breaks the competition. It's on an entirely different level of improbability, and should compete with "just sailing over the edge of the world, and keeping some cable to reel yourself back in".

[wumpus]

In order of silliness/hype...

EM drive: impossible. Not only impossible, but you could presumably do the same thing by using a cyclotron-based system as a rocket for arbitrarily high Isp.  So you are presumably working on a system that relies on breaking the laws of physics instead of something that will possibly work (I'm not pretending that the energy efficiency of either makes sense, just the ISP).

Space Cannon: don't even think about it in a single stage, might make sense as a first stage.  Downside: presumably exists entirely to send fuel and other raw materials into space, and requires a massive number of launches to justify itself.  Likely obsoleted before construction is finished by Martian/asteroid colonies.

SSTO: A favorite of those who have no understanding of the rocket equation.  Anything an SSTO can do, a "TwoSTO" can do better (especially since spacex has demonstrated landing a first stage).  Really should go down lower on the list do remotely possible systems like the X-43 project, escape dynamics, and SABRE (all of which rely on huge ISPs), but it comes up enough and needs to be heavily squashed.

Space Fountain: Only down this far due to lack of perceived hype.  Wildly more silly than a space cannon, but this is sufficiently obvious to keep it from coming up too often.

Space Loop: Same issues as the space fountain.  All the issues of a space cannon only with more complexity (although crewed flight is remotely possible).

Space Elevator: Basically requires unobtanium.  Fortunately, small batches of unobtanium are available in labs (for sizes not even close to workable).  If you really want to get into space (and have the unobtanium), you will build this.

Orion: Considering the thing has been possible to build since the 1960s, this can only go at the end.  Yes, there are huge issues (and it has to be launched from Antarctica), but things like that nifty laser the Navy is using might make things more interesting (that laser would come in handy for a few other interesting crafts, but since the whole point would be causing fusion explosions the classification of the laser would be insignificant to the overall classification of the Orion).

[Spaceception]

The space cannon/loop/fountain ones sound the most ridiculous, the elevator might be good on Earth, but probably preferable on Mars (At least easier), and Orion could be used someday (Or some variant), and as for Emdrive, I dunno, maybe, but I'm not sure, and SSTOs could probably be useful for small payloads, and launching stuff on smaller planets/moons.

[p1t1o]

The various things on the list, some of them probably never will happen, some of them will probably be quite useful for future use on bodies with lower gravity, so its hard for me to say which will never be used, or which will be used most, given no stipulated timeframe.

But I've always had a weird thing about Orion. It is supposedly very well supported by theory, mathematics and what-have-you, in that its capabilities should be exactly what has been calculated - abilities which are quite significant.

But I just cannot get past the whole exploding H-bombs a few yards away from your craft being at all sensible.

And more than that, sometimes figures are given about the amount of energy being harvested from each explosion, sometimes very high percentages given (I forget what the highest I saw has been but somewhere in the 50% ballpark). Im sure the "shaped charge" scheme they have going will increase the energy capture, but up to 50%? 

Im sure the maths is very sound, but I just dont buy it.

And that is hard for me, being all sciencey and whatnot.

 

(Though the whole "Cant be launched from Earth" thing doesnt seem to be an impediment for me...just build it in space...)

[Bill Phil]

7 minutes ago, p1t1o said:

The various things on the list, some of them probably never will happen, some of them will probably be quite useful for future use on bodies with lower gravity, so its hard for me to say which will never be used, or which will be used most, given no stipulated timeframe.

But I've always had a weird thing about Orion. It is supposedly very well supported by theory, mathematics and what-have-you, in that its capabilities should be exactly what has been calculated - abilities which are quite significant.

But I just cannot get past the whole exploding H-bombs a few yards away from your craft being at all sensible.

And more than that, sometimes figures are given about the amount of energy being harvested from each explosion, sometimes very high percentages given (I forget what the highest I saw has been but somewhere in the 50% ballpark). Im sure the "shaped charge" scheme they have going will increase the energy capture, but up to 50%? 

Im sure the maths is very sound, but I just dont buy it.

And that is hard for me, being all sciencey and whatnot.

 

(Though the whole "Cant be launched from Earth" thing doesnt seem to be an impediment for me...just build it in space...)

More than 50, about 80%. It's crazy, but if you over-engineer it enough, it would work, and that's the insane part. Even a small Orion has great performance, and there is a variant called "mini-mag Orion" that doesn't use bombs.