B Creating drag to reduce falling speed

[alikim]

TL;DR Summary

Can a bunch of long strips of a strong light-weight material significantly reduce speed when falling from outer space?

Theoretically, if a person falls from outer space to earth, and they hold 10000 rolls of toilet paper by their loose end, will that slow their fall down? Can you do that with a rocket booster returning to earth, keeping its speed subsonic all the way?
On more serious note, what happens if you that and replace toilet paper with a strong enough material like the one parachutes made of?
Had anyone ever tested this?

 

[DaveC426913]

Anything that creates drag by friction with air is going to be virtually ineffective until the air is dense enough. Parachutes only work effectively in the lower, denser atmosphere.

You mention rockets. That raises a separate issue: how much velocity are you trying to kill?

Simply falling from space - i.e. starting at v=0 - will get you a very different velocity than a deorbiting rocket, which could be moving at Mach 25. Parachutes will be shredded at those speeds. There's a reason we use aerobraking.

It would help if you clarified the application of your idea: what starting scenario do you envision? Falling out of a high altitude balloon? A first stage booster rocket that doesn't reach orbital velocity? An orbital vehicle deorbiting?

 

[alikim]

I'm just curious, if such device could find an application, I don't have any particular case in mind. For example, modules returning from space, first use heat shield to slow down and then parachutes to land.
Could such drag system be used at some point of descend to alleviate requirements/need for heat shield for example?
Yes, parachutes will be shredded at high speeds, but these are not parachutes, that's the whole point. You could find a sweet spot between the amount of drag and their survivability.

 

[fresh_42]

I'm just curious, if such device could find an application

If you cannot answer the questions about height, starting velocity, and mass, then ...

Can a bunch of long strips of a strong light-weight material significantly reduce speed when falling from outer space?

... can only be answered by a no. It sounds to me as if it wouldn't create significant drag even for a human on a parachute. Falling from space into an atmosphere will likely burn or rip those materials.

 

[DaveC426913]

I'm just curious, if such device could find an application, I don't have any particular case in mind. For example, modules returning from space, first use heat shield to slow down and then parachutes to land.
Could such drag system be used at some point of descend to alleviate requirements/need for heat shield for example?

Why? What's wrong with the system they have now? What perceived problem are you trying to solve?

Yes, parachutes will be shredded at high speeds, but these are not parachutes, that's the whole point. You could find a sweet spot between the amount of drag and their survivability.

They have.

 

[sandy stone]

Just an observation, reusable model rockets often use an alternative to parachutes called "streamer recovery", in which they deploy a long crepe-paper strip that slows their fall. Of course, these are very lightweight objects moving relatively slowly to start with, so applying this method to a full-size rocket would be problematic. Just pointing out that the concept is useful in certain situations.

 

[russ_watters]

Streamers are used on some model rockets, but only the lightest/lowest density ones.

You can't put multiple streamers on one object without some structure to separate them, so you have to increase the size of the single streamer. Doing so means it also has to be stronger and heavier. So no, I don't see how they would be useful for large objects except maybe as a drogue/stabilization chute.

 

[Andy Resnick]

TL;DR Summary: [...]
Had anyone ever tested this?

Sort of- Felix Baumgartner jumped from 130k feet



You will see he free-fell most of the way down.