Non rocket assisted methods for landing

[kunok]

We talked here a lot for alternative methods of launching cargo to space, like the launch loop, but what about landing? most of these systems would require extreme precision to be used for landing or aren't viable at all.

What method you propose and why?

[hugix]

We place a ton of cardboard boxes on the ground where the first stage is supposed to land thus softening the landing.

[PB666]

Barge made of aerogel covered with a ton of really flammable cardboard boxes,

[kunok]

And lithobraking jokes apart?

For example, a mass driver I think is not a viable option for bodies with a light atmosphere, you won't have the enough precision for aiming the mas driver because the turbulence derive from the little atmosphere (and the atmosphere isn't enough to use only aerobraking to land), and I will be very hard to do even in atmosphereless bodies.

[PB666]

30 minutes ago, kunok said:

And lithobraking jokes apart?

For example, a mass driver I think is not a viable option for bodies with a light atmosphere, you won't have the enough precision for aiming the mas driver because the turbulence derive from the little atmosphere (and the atmosphere isn't enough to use only aerobraking to land), and I will be very hard to do even in atmosphereless bodies.

how about aquabaking? Another one put extendable propellar blades as drag planes and allow it to autorotate onto the barge, of course covered with very flammable cardboard, on top of the aerogel on top of the barge (for lithobraking), on top of the water for aquabreaking.

The best of all possible ways to smash something into 100s of spinning, radiating, on fire, shattered, and finally wet pieces.

 

[kerbiloid]

, but with large fan.

Also, this is a launcher.

With SpaceX precision this makes sense. This aerotube stays in the backyard of Musk's facility, catching the falling stages and dragons, spitting up falcons.

No more land rent or so is required, just a backyard or a gothic castle.
Here you can see a Standalone Rocket Facility with an aerotube at its right side,
(Also this will assign a clear meaning to: why Dragon needs to precisely land onto a bull's eye rather than other ships which are happy with their chutes and a piece of desert.)
 

Edited May 9, 2016 by kerbiloid

[kunok]

Don't make this thread another spaceX thread please, I'm not talking even about landing in earth. I'm talking about landing in general, of course earth is a option, but in earth at least has enough atmosphere for making an aerobrake assisted landing.

[magnemoe]

You could land at orbital speeds, people has done wheeled landings on the flats on Minmus. 
Two ways to do this in, one to fly into an coil gun accelerator and let it slow you down.
Second would be to land on an totally flatt surface and let the drag stop you, you are likely to have to replace the landing skis. 
Both would require very high presisjon, this is doable however any fail would be catastrophic. 

[shynung]

1. Equip spacecraft with landing wheels/skids and an anchor-reel combination.

2. Lower orbital periapsis until it is less than 5 meters above a flat surface, preferably a prepared field.

3. Fire anchor backwards and downwards at final approach; let anchor snag on the surface, unreeling anchor/braking line.

4. Apply brakes to reel, slowing the craft down; if reel runs out of cable, release cable, brake the craft using emergency braking rockets.

5. Touch down, apply brakes to landing gear.

6. ???

7. Profit!

[sevenperforce]

Build a very large (30+ miles) coil gun in orbit. Give it a bunch of solar panels for power, and a flywheel or supercapacitor banks to store solar energy. Then, if you want to deorbit, let it fire you retrograde. If you want to orbit, on the other hand, take a high-altitude balloon to the edge of space and then hover on thrusters so as to intercept the front end of the coil gun.

For landing itself...why not be a blimp?

Edited May 9, 2016 by sevenperforce

[PB666]

5 hours ago, kunok said:

Don't make this thread another spaceX thread please, I'm not talking even about landing in earth. I'm talking about landing in general, of course earth is a option, but in earth at least has enough atmosphere for making an aerobrake assisted landing.

Well if not about landing on earth the easiest landing is on an asteroid, of course with a SpaceX Dr . . . . . . . . . . . .what? not about SpaceX?

[wumpus]

On 5/9/2016 at 3:45 AM, kunok said:

Don't make this thread another spaceX thread please, I'm not talking even about landing in earth. I'm talking about landing in general, of course earth is a option, but in earth at least has enough atmosphere for making an aerobrake assisted landing.

Because Earth is the most important place to land and the most obvious place to do so without retrorockets.  The only means of landing elsewhere I'm aware of used an "airbag landing" where the spacecraft would inflate an airbag and bounce multiple times until it came to a stop.

I'd suggest reading about the "interplanetary Cessna" first (I'm sure it had way more research than I did): https://what-if.xkcd.com/30/

Mercury: no atmosphere, need rockets.

Venus: Has an extreme atmosphere.  Some combination of aerobraking, parachutes, and rockets are recommended.  Note that it is critical to decrease the time to landing (don't try to do it all with aerobraking/parachutes) because you have a limited time before your spacecraft melts.

Earth: Don't forget Soyuz landings: parachute landings that use rockets at the last few seconds.

Moon: no atmosphere, rockets needed (airbag landing may have worked).  Warning: due to the lack of atmosphere moon rocks are as sharp as anything just broken with a hammer.  Lunar dust is equally sharp and gritty.  You need an amazingly *tough* airbag.

Mars: secondmost well studied place for aerobraking/aerocapture.  Airbags more likely to have worked (there is at least *some* atmosphere to wear down the edges).  The atmosphere is pretty thin so expect to need rockets at the end (although if you have astronauts that can climb out and wipe off the lander you hardly need Curiosity's outlandish landing contraption).

Beyond: You can't land on gas giants, so that is out.  Few things smaller have an atmosphere, and those that do (Titan may be an exception) are pretty thin (moreso than Mars) and will require rockets.

Titan: Your best bet.  Take your pick, but the moon is small enough that a few rockets at the end won't have as much gravity to fight.

Edited May 11, 2016 by wumpus
note: not not

[PB666]

52 minutes ago, wumpus said:

Because Earth is the most important place to land and the most obvious place to do so without retrorockets.  The only means of landing elsewhere I'm aware of used an "airbag landing" where the spacecraft would inflate an airbag and bounce multiple times until it came to a stop.

I'd suggest reading about the "interplanetary Cessna" first (I'm sure it had way more research than I did): https://what-if.xkcd.com/30/

Mercury: no atmosphere, need rockets.

Venus: Has an extreme atmosphere.  Some combination of aerobraking, parachutes, and rockets are recommended.  Note that it is critical to decrease the time to landing (don't try to do it all with aerobraking/parachutes) because you have a limited time before your spacecraft melts.

Earth: Don't forget Soyuz landings: parachute landings that use rockets at the last few seconds.

Moon: no atmosphere, rockets needed (airbag landing may have worked).  Warning: due to the lack of atmosphere moon rocks are as sharp as anything just broken with a hammer.  Lunar dust is equally sharp and gritty.  You need an amazingly *tough* airbag.

Mars: secondmost well studied place for aerobraking/aerocapture.  Airbags more likely to have worked (there is at least *some* atmosphere to wear down the edges).  The atmosphere is pretty thin so expect to need rockets at the end (although if you have astronauts that can climb out and wipe off the lander you hardly need Curiosity's outlandish landing contraption).

Beyond: You can't land on gas giants, so that is out.  Few things smaller have an atmosphere, and those that do (Titan may be an exception) are pretty thin (moreso than Mars) and will require rockets.

Titan: Your best bet.  Take your pick, but the moon is small enough that a few rockets at the end won't have as much gravity to fight.

Cessna is a horrifically bad idea just about under any circumstance, even titan is dubious, hand glider, lol before you get a hand glider to pedal up to speed your fingers and toes have frozen, your body temperature has dropped and you are dying. I think the Curiousity's drop method or SpaceX style relanding are the best bet for most of the atmosphere-less celestials.

 

Edited May 11, 2016 by PB666

[wumpus]

Just now, PB666 said:

Cessna is a horrifically bad idea just about under any circumstance, even titan is dubious, hand glider, lol before you get a hand glider to pedal up to speed your fingers and toes have frozen, your body temperature has dropped and you are dying. I think the Curiousity's drop method or SpaceX style relanding are the best bet for most of the atmosphere-less celestials.

 

I'm fairly sure that the question Randal was asked was if such a plane could fly in the atmosphere, not if it could aerobrake from orbital velocity (or aerocapture from an intercept course).  The point was that very few planets can provide the lift for non-rocket flight.

[PB666]

But its more problematic than that. Cessna's have a higher energy density and lose mass as they fly, the mass loss of lithium ion batteries is negligible they have a higher density and lower energy density (because half of the engines fuel density comes from air). The lithium ion batteries need to be heated constantly in the coldness of the outer solar system. The engine would have to be replaced with an electric motor, and its not even certain that the prop would survive the cold operating temperatures, the glass windshield would need to be replaced with cameras or some double glass insulation, the weight in insulation would add 20% more weight to the airframe, the crew has to carry their own oxygen, the cabin would need to be pressurized, the landing gear would have to be replaced with skids, the weight distribution would change and the wings would have to be moved. 

Second I am addressing the rest of the post concerning drops with inflatables, that only works really well for small objects on relatively cold planets, Mars in particular, for the other planets, not so sure thats going to be any use. So you need some retro-thruster to take away orbital velocity to land.

Third, when people get all dreamy-eyed about landing living flesh on other worlds they seem to instantaneously forget all the rather stark differences between those worlds and earths. Things like:

Nitrogen liquefying out of the air at ground level in dark spots, the ground may not be compacted and have the consistency of very lose snow, the air is so cold. In the case of Venus, its metal warping hot, ion-batteries will not survive. I don't know if anyone here has ever working in Liquid Nitrogen, I've had to remove samples under the liquid surface, the cold penetrates very very quickly. You can suffer frost bite in seconds under the protection of insulated gloves and with a liquid shield, in fact its safer to dip your hands directly in and grab a sample than where any kind of protective glove because the gloves just bind the cold to flesh. Gloves may protect you from heat, that is because the moisture of the skin acts as a coolant and heat decreases density, they are very poorly protective against extreme cold. Everything contracts in the direction of the skin. If you take liquid nitrogen and place it in a low density plastic beaker, and place that in another plastic beaker, within a few seconds ice crystals begin to grow on the outside of the second glass beaker, this is because the nitrogen in the air acts as a catalyst for for energy transfer. Insulatoins break down also, I see tanks out in the halls here that simply don't hold nitrogen anymore because the insulation, sealed entirely, breaks down because of the hot/cold differential.

Frozen carbon dioxide and water take on a different consistency than solid ice.

The outer planets are altogether hostile for advanced life, and require long trips through rather inhospitable space. There may be life at the bottom of some sea on Enceladas, I'm not going to discount that possibility, but fishing out of ice-hole is insane.

 

 

[RainDreamer]

Rendezvous with an orbital magnetic rail, have the rail slow you down using magnetic field in a spiral until you are slow enough to be captured and carry on the rail to the ground.

Hey, the question isn't asking for a reasonable/probable way.

[sevenperforce]

24 minutes ago, RainDreamer said:

Rendezvous with an orbital magnetic rail, have the rail slow you down using magnetic field in a spiral until you are slow enough to be captured and carry on the rail to the ground.

Hey, the question isn't asking for a reasonable/probable way.

Surprisingly, once you run the numbers it turns out that a 50+ km orbital coilgun is actually one of the more reasonable ways to kill orbital velocity, regardless of whether you have an atmosphere or not.

[PB666]

18 minutes ago, RainDreamer said:

Hey, the question isn't asking for a reasonable/probable way.

No reason or logic. Fine

A magic umbrella like the one Mary Poppins used.
A quantum fragmentor that seriallizes all consituents to small bits, then waits until those bits randomly assume the right momentum and then places the bits back in the right spatial position.
Lets see a huge rubber bouncy ball as a heat shield in which the sheild burns off completely leaving a bouncy ball.
A huge leather baseball mitt to catch the craft with.
A large spiral slide where the craft intercepts the end of the slide and then bobsleds around on it until all its forward momentum is lost to friction.
A huge speaker that blasts low frequency sound at the craft.
A pair of space suspenders that pull the craft back and hurl a second craft at high speed into the earth (a space wedgey).

Im sure there are an infinite number of very bad ideas.

 

 

 

[magnemoe]

1 hour ago, PB666 said:

Third, when people get all dreamy-eyed about landing living flesh on other worlds they seem to instantaneously forget all the rather stark differences between those worlds and earths. Things like:

Nitrogen liquefying out of the air at ground level in dark spots, the ground may not be compacted and have the consistency of very lose snow, the air is so cold. In the case of Venus, its metal warping hot, ion-batteries will not survive. I don't know if anyone here has ever working in Liquid Nitrogen, I've had to remove samples under the liquid surface, the cold penetrates very very quickly. You can suffer frost bite in seconds under the protection of insulated gloves and with a liquid shield, in fact its safer to dip your hands directly in and grab a sample than where any kind of protective glove because the gloves just bind the cold to flesh. Gloves may protect you from heat, that is because the moisture of the skin acts as a coolant and heat decreases density, they are very poorly protective against extreme cold. Everything contracts in the direction of the skin. If you take liquid nitrogen and place it in a low density plastic beaker, and place that in another plastic beaker, within a few seconds ice crystals begin to grow on the outside of the second glass beaker, this is because the nitrogen in the air acts as a catalyst for for energy transfer. Insulatoins break down also, I see tanks out in the halls here that simply don't hold nitrogen anymore because the insulation, sealed entirely, breaks down because of the hot/cold differential.

Frozen carbon dioxide and water take on a different consistency than solid ice.

The outer planets are altogether hostile for advanced life, and require long trips through rather inhospitable space. There may be life at the bottom of some sea on Enceladas, I'm not going to discount that possibility, but fishing out of ice-hole is insane.

 

Benefit with cold is that you can use heating to make it warm, far harder to cool something. 
However liquid nitrogen draws heat fast, not sure if even spacesuit gloves are good enough for this.
First thing I learned working with it was that clotting like cotton was far more dangerous than naked skin as spill would just run off skin like an water drop on an hot plate, while it would be absorbed by clothing and then it would case burns. 

[PB666]

2 hours ago, magnemoe said:

Benefit with cold is that you can use heating to make it warm, far harder to cool something. 
However liquid nitrogen draws heat fast, not sure if even spacesuit gloves are good enough for this.
First thing I learned working with it was that clotting like cotton was far more dangerous than naked skin as spill would just run off skin like an water drop on an hot plate, while it would be absorbed by clothing and then it would case burns. 

You know the feeling, and it burns all the way to the bone.

 

[Xyphos]

I was going to suggest a magnetic coil, but @RainDreamer beat me to it.
the only difference, my version would have been backwards; the vessel rides the rail down to the ground first, then magnetically brakes.

[wumpus]

21 hours ago, sevenperforce said:

Surprisingly, once you run the numbers it turns out that a 50+ km orbital coilgun is actually one of the more reasonable ways to kill orbital velocity, regardless of whether you have an atmosphere or not.

Are you really suggesting it is easier to build and land on a 50+ km orbital coilgun than to build a runway on the surface of a planet, especially with some sort of tailhook scheme similar to those used on aircraft carriers?  I suppose you *could* use the coilgun to scavenge the energy from orbit, but the civilization capable of building such things is unlikely to need it (current US carrier design uses electric catapults.  I strongly doubt anybody bothers scavenging electricity from the tailhook landings).

[sevenperforce]

2 hours ago, wumpus said:

Are you really suggesting it is easier to build and land on a 50+ km orbital coilgun than to build a runway on the surface of a planet, especially with some sort of tailhook scheme similar to those used on aircraft carriers?  I suppose you *could* use the coilgun to scavenge the energy from orbit, but the civilization capable of building such things is unlikely to need it (current US carrier design uses electric catapults.  I strongly doubt anybody bothers scavenging electricity from the tailhook landings).

No, that's a way to deorbit, not a way to land or to orbit in the first place. Though I suppose you could use it for the latter purpose.

Its primary value would be for worlds without enough atmosphere for aerobraking.

Assuming you have autonomous asteroid mining or some other way to get a lot of raw materials in space, build a 30+ km platform in LEO with a gigantic coil gun in it. Set up solar panels and some sort of energy storage mechanism (flywheels or supercapacitors). When you want to deorbit your spacecraft, you simply load the spacecraft into one end of the coil gun and fire it retrograde, killing its orbital velocity. Far less propellant needed for the deorbit (or, in the alternative, a much easier shot at lithobraking or other landing methods).

[wumpus]

3 hours ago, sevenperforce said:

No, that's a way to deorbit, not a way to land or to orbit in the first place. Though I suppose you could use it for the latter purpose.

Its primary value would be for worlds without enough atmosphere for aerobraking.

Assuming you have autonomous asteroid mining or some other way to get a lot of raw materials in space, build a 30+ km platform in LEO with a gigantic coil gun in it. Set up solar panels and some sort of energy storage mechanism (flywheels or supercapacitors). When you want to deorbit your spacecraft, you simply load the spacecraft into one end of the coil gun and fire it retrograde, killing its orbital velocity. Far less propellant needed for the deorbit (or, in the alternative, a much easier shot at lithobraking or other landing methods).

The catch is that on worlds without an atmosphere, I can't see how a 50km+ coilgun is any easier to land on than a runway on an airless world.  The benefits are that you can transmit the shock of landing onto the moon/planet while you have to design the 50km coilgun sufficiently rigid to handle the shock along the entire coilgun (all 50km need such robustness).  Certainly landing on a runway at greater than escape velocity is a dangerous plan, but hitting the coilgun wrong (at >escape velocity) is going to be equally fatal and do more damage to the coilgun.

And once you stop on the runway, you no longer need to land on the planet/moon.  Assuming the coilgun is in orbit, you still have to land.

[PB666]

9 minutes ago, wumpus said:

The catch is that on worlds without an atmosphere, I can't see how a 50km+ coilgun is any easier to land on than a runway on an airless world.  The benefits are that you can transmit the shock of landing onto the moon/planet while you have to design the 50km coilgun sufficiently rigid to handle the shock along the entire coilgun (all 50km need such robustness).  Certainly landing on a runway at greater than escape velocity is a dangerous plan, but hitting the coilgun wrong (at >escape velocity) is going to be equally fatal and do more damage to the coilgun.

And once you stop on the runway, you no longer need to land on the planet/moon.  Assuming the coilgun is in orbit, you still have to land.

This thread just keeps making more an more sense.

Here's what you do, use the coilgun like a baseball bat and whack the landing object strait up, the have it land in a whole that goes through the planet, as its going through the planet have magnets slow it down to a stop. Problem solved.