Author Topic: Magnetoshell Aerobraking & Aerodynamics  (Read 38890 times)

Online sanman

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Magnetoshell Aerobraking & Aerodynamics
« on: 09/16/2012 12:01 AM »
Can magnetoshells be used for more effective aerobraking and aerodynamics, whether on Earth or other planets?

http://www.nasa.gov/offices/oct/early_stage_innovation/niac/2012_phase_I_fellows_kirtley.html


Offline aero

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #1 on: 09/16/2012 12:41 AM »
Well, according to the link you provided, yes.

I'm wondering if they can be used to benefit reusablity of rocket first and second stages. I would think yes for the second stage, maybe for the first stage due to the high atmospheric density and required ionization energy.

Of course that is contingent on their working at all.
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Online sanman

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #2 on: 09/16/2012 02:22 AM »
Well, I'm assuming it provides relatively more benefit in thinner atmosphere, since there's probably no boundary layer issues with this.


Also, they mention manned landings, so I wonder if the magnetic field would be harmful to biological (human) payloads. However, they do say it's low-powered, so maybe then it's not so harmful.

I wonder if this tech would also be good for steering scramjet vehicles as well.

Offline kch

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #3 on: 09/16/2012 02:42 AM »
There is much to wonder about ... it should be interesting to revisit this thread over the years ahead as the answers become clear.  At the moment, questions are about all we have, particularly about the timeframe of this project.

Offline go4mars

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #4 on: 09/16/2012 04:08 AM »
Neato.  I wonder what kind of funding and timeline this will get.
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Online sanman

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #5 on: 09/16/2012 07:19 PM »
Not wanting to deviate too much into the military sphere, but I'm curious - could this type of tech be useful for MIRV?

I was just thinking that something with potential military utility could attract much greater research funding, thus accelerating its development and progress.
« Last Edit: 09/16/2012 07:28 PM by sanman »

Offline Cedalion

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #6 on: 09/20/2012 04:13 AM »

Offline Jim

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #7 on: 09/20/2012 11:23 AM »
Not wanting to deviate too much into the military sphere, but I'm curious - could this type of tech be useful for MIRV?


How so?  They don't need braking.

Offline spaceStalker

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #8 on: 09/20/2012 01:02 PM »
Not wanting to deviate too much into the military sphere, but I'm curious - could this type of tech be useful for MIRV?


How so?  They don't need braking.

Someone has to pay for the development :)

Online sanman

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #9 on: 09/20/2012 01:10 PM »
Not wanting to deviate too much into the military sphere, but I'm curious - could this type of tech be useful for MIRV?


How so?  They don't need braking.

No, but anything that can be used for braking can be used for steering as well - just manipulate the field. Certainly MIRVs could benefit from being steered to target, or even steered for evasive purposes on the way down.
« Last Edit: 09/20/2012 01:11 PM by sanman »

Offline Asteroza

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #10 on: 09/21/2012 12:47 AM »
Powering the magnets for this may be non-trivial.

But there may be a solution, for aerobraking around bodies with magnetospheres, such as earth.

Assuming the magnet is superconducting, if you had a source of power/current to quick charge the magnet, you could leave it unmagnetized most of the time.

So what would be the power source? How about a disposable braking electrodynamic tether? Since you are low in the magnetosphere and traveling a high velocity, you can generate a fair amount of power from a braking tether. As an additional factor, while the tether itself won't provide enough reduction in deltaV to make reentry painless, but it may provide enough to avoid a large retro burn for reentry. May need a drag kite plate at the end of the tether to use atmospheric drag to steer the tether upright, otherwise it would just stream behind the space craft.

How it would interact with the growing field from the reentry magnet is an issue. The tether does have the convenient aspect of burning loose when reentry gets warmer (though it needs to be able to deorbit by its own drag when cut loose).

Online KelvinZero

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #11 on: 09/21/2012 01:35 AM »
Hopefully it creates its own power as it applies drag against the ionised atmosphere like a form of MHD generator?

Im unclear about the expected weight of this contraption though.. they did seem to dismiss it a bit glibly by describing it as "a massless field and a gram of plasma".
« Last Edit: 09/21/2012 01:39 AM by KelvinZero »

Offline jongoff

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #12 on: 09/21/2012 02:18 AM »
This reminds me of some interesting work I saw a while ago on using magneto-hydrodynamic forces for aerobraking and thermal protection...

Here it is - probably discussed previously on this forum somewhere:
http://selenianboondocks.com/2010/02/mhd-aerobraking-and-thermal-protection-part-i-introduction/
http://selenianboondocks.com/2010/02/mhd-aerobraking-and-thermal-protection-part-ii-atmospheric-reentry-for-rlvs/
http://selenianboondocks.com/2010/02/mhd-aerobraking-and-thermal-protection-part-iii-aerobraking-and-aerocapture/

Yeah, I enjoyed writing those articles. I've pinged the guy who is running that NIAC project to see if I can do another blog post about their idea and how it differs from these other approaches.

~Jon
« Last Edit: 09/21/2012 02:22 AM by jongoff »

Offline Jim

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #13 on: 09/21/2012 03:02 AM »

No, but anything that can be used for braking can be used for steering as well - just manipulate the field. Certainly MIRVs could benefit from being steered to target, or even steered for evasive purposes on the way down.

They already are, using systems that are simpler and less complicated.

Online sanman

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #14 on: 09/21/2012 03:18 AM »

No, but anything that can be used for braking can be used for steering as well - just manipulate the field. Certainly MIRVs could benefit from being steered to target, or even steered for evasive purposes on the way down.

They already are, using systems that are simpler and less complicated.

Okay, fair enough, Jim - but what about stuff like hypersonic vehicles/missiles? A recent hypersonic test failed because the control surfaces weren't effective. With magnetism, you could probably exert much better control authority, without worrying about mechanical failure due to the high stresses of hypersonic flight.

Offline Jim

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #15 on: 09/21/2012 03:39 AM »

Okay, fair enough, Jim - but what about stuff like hypersonic vehicles/missiles? A recent hypersonic test failed because the control surfaces weren't effective. With magnetism, you could probably exert much better control authority, without worrying about mechanical failure due to the high stresses of hypersonic flight.

My point is still applicable.  Still have the greater complexity in generating the power and then manipulating the magnetic field.

And no, you wouldn't have more control authority and the magnetic field would have more drag.

Also, not every discovery has spaceflight implications. That is all you seem to post.  "oh, here is something new, can it be used for space'?

"This one a long time have I watched. All his life has he looked away... to the future, to the horizon. Never his mind on where he was. "
« Last Edit: 09/21/2012 03:44 AM by Jim »

Online sanman

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #16 on: 09/21/2012 04:49 AM »
Well, Jim, the link in my original post was from NASA - apparently they feel that Magnetoshells may have applications for spaceflight purposes.

And yes, I feel that we should always look at new developments in science and technology, and assess their implications for things that are useful to us.

Brakes/drag when applied selectively can be used to steer with, and that would likewise apply to magnetic braking/drag.

The problem with conventional mechanical braking in the hypersonic regime is the insufficient level of contact - especially in less dense atmosphere. That's why Curiosity had to land with rockets, because there wasn't enough atmosphere for the chutes to grab onto. A magnetic field could be expanded to contact much more atmosphere, to grab at it. And because it doesn't have conventional moving parts, it's less prone to failure.




Offline Jim

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #17 on: 09/21/2012 10:05 AM »

The problem with conventional mechanical braking in the hypersonic regime is the insufficient level of contact - especially in less dense atmosphere. That's why Curiosity had to land with rockets, because there wasn't enough atmosphere for the chutes to grab onto. A magnetic field could be expanded to contact much more atmosphere, to grab at it. And because it doesn't have conventional moving parts, it's less prone to failure.

Wrong on all accounts.  You have no basis to make such statements.

Offline RanulfC

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #18 on: 09/21/2012 12:18 PM »

The problem with conventional mechanical braking in the hypersonic regime is the insufficient level of contact - especially in less dense atmosphere. That's why Curiosity had to land with rockets, because there wasn't enough atmosphere for the chutes to grab onto. A magnetic field could be expanded to contact much more atmosphere, to grab at it. And because it doesn't have conventional moving parts, it's less prone to failure.

Wrong on all accounts.  You have no basis to make such statements.
I'll use Jims post to point out some "information" that seems to have been "lost" in the discussion;

Magnetic fields only cause "drag" within magnetic fields not within a medium itself. Toss a magnet and you won't see it "slowing" down until the ground interupts its free-fall trajectory :)

THIS system uses very high hypersonic speeds (talking over Mach-12 here) to generate a PLASMA which is then manipulated by a magnetic field into acting like a larger surface area for atmospheric, (not magnetic) interfacing. While it can be used to "steer" by manipulating the size, shape, and density of the plasma the effect is going to be less effective as pressure increases due to the nature of the plasma itself.

The power requirements would seem to be modest as it says it would require NO superconductors.

The biggest "issue" with Mars EDL for large payloads is the SIZE of parachutes needed for soft landing, this concept doesn't really "help" with that other than allowing a higher deceleration to be achieved in the very thin upper atmosphere. You would still need large parachutes (or rockets) to continue to decellerate once the speed no longer generated a sufficent plasma for the magnetic field to manipulate.

You would need an EXTREMELY powerful magnetic field generator to get ANY "control" without the plasma field and then you would NOT be interacting with the atmosphere but the planetary magnetic field. Magnetic "control" doesn't work simply because of the power and field strength requirments to even BEGIN interacting enough to be noticed :)

Randy
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Offline jongoff

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #19 on: 09/21/2012 04:26 PM »
The area where (depending on details of how this works) I'm most interested in this and related MHD aerobraking concepts is in enabling capture and reuse of in-space elements. Ie, think real spaceships, that get reused a bunch of times, that don't have to look like a big reentry capsule.

Imagine for instance if you could use this to take Centaur-derived tanker coming back from L2, and brake it into LEO using a miniscule amount of propellant.

Or imagine having a spacecraft like Nautilus-X, or a combination of Bigelow Modules combined with a backbone and some propulsion, that used something like this to enable it to quickly and safely capture into LEO after returning from the Moon or Mars. Or capturing into Mars orbit after a trip from earth.  Being able to non-propulsively knock off most of the energy needed to go from a hyperbolic orbit to a low orbit around Earth, Mars, Venus, or anywhere with an atmosphere, without needing a huge heat shield I think might be more game changing than most realize.

That said, I'd like to get more details on how this concept works, because I'm not sure it can actually do what I'm suggesting above.

~Jon

Tags: aerocapture