Author Topic: Magnetoshell Aerobraking & Aerodynamics  (Read 38889 times)

Online sanman

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #20 on: 09/22/2012 08:23 AM »
So when it comes to magnetoshell aerobraking and conventional aerobraking, each will have its preferred atmospheric regime where it performs best. Nobody's claiming that magnetoshells mean you don't need conventional parachutes or aerobody surfaces, just that the magnetoshell approach can further reduce the load on the conventional aerodynamic systems. This provides an extra performance margin, while reducing the potential for failure.


Offline 93143

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #21 on: 09/22/2012 09:14 PM »
It is my understanding that the magnetoshell idea is more for aerocapture, which is currently a very dubious endeavour due to the unpredictability of upper atmosphere conditions.  The ability to directly modulate drag would be very useful here, and it might also allow greater flexibility in vehicle design.

Online sanman

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #22 on: 09/23/2012 02:50 AM »
But also remember that there is a higher component of ionic species in the upper atmosphere/ionosphere. So that will work even more in the magnetoshell's favor, to help its performance.

Offline aero

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #23 on: 09/23/2012 04:03 AM »
I haven't read any comments regarding the RMF. Quoting from the original link (first post) in this thread:

Quote
This plasma is formed, sustained, and expanded with an electrodeless Rotating Magnetic Field (RMF), which has been shown in previous experiments to generate the required, fully ionized, high temperature magnetized plasma.

Is that not significant?

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Online Robotbeat

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #24 on: 09/24/2012 08:32 PM »
It is my understanding that the magnetoshell idea is more for aerocapture, which is currently a very dubious endeavour due to the unpredictability of upper atmosphere conditions.  The ability to directly modulate drag would be very useful here, and it might also allow greater flexibility in vehicle design.
Aerocapture around /Mars/ (and other non-Earth worlds) is what is dubious because of the lack of extensive knowledge about the upper atmosphere there. It's more predictable for aerocapture at Earth.
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Offline SpaceWeaselUMICH

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #26 on: 07/23/2013 09:12 AM »
It is my understanding that the magnetoshell idea is more for aerocapture, which is currently a very dubious endeavour due to the unpredictability of upper atmosphere conditions.  The ability to directly modulate drag would be very useful here, and it might also allow greater flexibility in vehicle design.
Aerocapture around /Mars/ (and other non-Earth worlds) is what is dubious because of the lack of extensive knowledge about the upper atmosphere there. It's more predictable for aerocapture at Earth.

By the time this is ready, I believe the MAVEN spacecraft will have returned scientific data on the upper atmosphere. (Assuming it avoids fiery destruction.)

Offline cordwainer

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #27 on: 07/24/2013 05:06 PM »
Had a wild idea related to another thread. Would it be possible to use a designer graphene or nano-tube composite to provide thermodynamic cooling to a turbine blade. Someone though it would be a good idea to stick a turbine behind a rocket's exhaust not just the cryogenic propellant stream, don't know what use this would have except maybe in a gas generator or thermopower wave device. But they did bring up the point that rocket turbines don't have blade cooling systems. Since graphene and nanotube wires exhibit semiconductive properties, could one lace a mesh of such wires through a material to manage a electromagnetic or electrostatic field that could be used in various ways? Like for instance a lightweight Faraday cage, controlling the shape and density of a magnetoshell or magnetohydrodynamic cooling for a high temperature rocket turbine. Traditional bladed turbines probably wouldn't the best design for such an application though, perhaps a disk or screw turbine design would offer the appropriate surface area to achieve an effective gain in heat management. 

Offline mfck

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #28 on: 05/05/2014 01:18 PM »
Congrats to Jon on SBIR Selection!

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #29 on: 05/05/2014 01:42 PM »

Offline Elmar Moelzer

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #30 on: 05/05/2014 02:53 PM »
Congrats to Jon and his team and to Dave and the other guys over at MSNW!
This is a really cool project!
« Last Edit: 05/05/2014 02:54 PM by Elmar Moelzer »

Offline jongoff

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #31 on: 05/06/2014 10:50 AM »
Thanks guys! I've been proposaling the last few days, so hadn't had a time to mention anything publicly about this, but Doug did a good writeup. This is pretty exciting for us!

~Jon

Offline JasonAW3

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #32 on: 05/07/2014 04:57 PM »
Tapping into the energy generated by the plasma during reentry could, in theory, help power such a system.
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Offline Elmar Moelzer

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #33 on: 05/07/2014 05:02 PM »
Tapping into the energy generated by the plasma during reentry could, in theory, help power such a system.
Yes, it does. It has essentially a dynamo effect. So the thing is self charging. There was a joint European Russian project at some point that was supposed to test that, but I don't think it ever happened.

Offline cordwainer

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #34 on: 05/09/2014 07:28 PM »
Question could charge excitation be used to propel objects via a high pressure gas gun? A sort of hybrid compressed air gun/coil gun. Such a system could be used to test the effectiveness of magnetoshell technology as well as be used to develop future mass drivers for space propulsion and military weaponry.

Offline MP99

Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #35 on: 05/09/2014 09:24 PM »
Congrats, Jon!

Offline JasonAW3

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #36 on: 05/23/2014 07:22 PM »
http://nextbigfuture.com/2013/06/magnetoshell-concept-proven-for-braking.html#more

If I understand the article correctly, this would act something like a Plasma Parachute in the upper atmosphere.

But if the Payload is actually in front of the Magnetized Plasma effect, wouldn't it too need some form of TPS?  I figure an Inflatable Hypersonic decellerator would work quite well for that.
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Offline jongoff

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #37 on: 05/24/2014 02:53 AM »
http://nextbigfuture.com/2013/06/magnetoshell-concept-proven-for-braking.html#more

If I understand the article correctly, this would act something like a Plasma Parachute in the upper atmosphere.

Yeah, that's the analogy we use a lot. It works reasonably well.

Quote
But if the Payload is actually in front of the Magnetized Plasma effect, wouldn't it too need some form of TPS?

It depends, but not exactly. While it's true that having the spacecraft inside the magnetoshell provides an extra level of protection versus atmospheric heating, just increasing the effective drag area means you can get the same amount of braking higher in the atmosphere, where the lower density means much less heat flux.

Instead of a ballistic coefficient of 250-500kg/m^2 that you see for capsules or the shuttle, or 25-50kg/m^2 that you get for a HIAD system, you can potentially get ballistic coefficients less than 1-5kg/m^2 with a properly designed Magnetoshell with the right bells and whistles...Potentially much less than 1kg/m^2...

Take their Mars aerocapture design. Compared to a 5m radius heatshield that you could theoretically get on an SLS-type vehicle, you could get a 20m radius magnetoshell using their design, and possibly as much as 40-50m radius magnetoshell using some reasonable tricks we've thought of since they did their paper. You're talking about an areal density somewhere between 16-100x lower than you could get with a traditional heat shield (and probably still 4-25x more than you could get with a HIAD. That means that for the same desired drag, you can do a pass where the density is 16-100x lower than you could with the traditional heatshield or 4-25x lower density than you could with a HIAD. Heat flux goes linearly with the density, so depending on the details, and the knobs twisted, even if your MAC coil is trailing on a tether, you still might not actually need TPS.

Oh, and that 20-50m radius magnetoshell can be made with a payload that fits into a 5m EELV fairing...

~Jon
« Last Edit: 05/24/2014 03:12 AM by jongoff »

Offline Burninate

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Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #38 on: 05/24/2014 06:44 AM »
That's fantastic.  This sounds like a remarkably enabling technology.  At the outset, it means you can ferry fragile orbital habitation modules and/or fuel depots between Mars, Earth, Venus, and Titan while only incurring half of the Wrath Of The Rocket Equation, and enables both rapid grav-assist trajectories, and low-thrust SEP missions which wouldn't otherwise have the thrust to precisely hit aerocapture windows in time.  This helps the mass balance a hell of a lot, especially for missions without ISRU.  The potential for lower heat-shield requirements, especially on very large missions, is enormous.

Congratulations.
« Last Edit: 05/24/2014 06:47 AM by Burninate »

Offline MP99

Re: Magnetoshell Aerobraking & Aerodynamics
« Reply #39 on: 05/24/2014 11:53 AM »
http://nextbigfuture.com/2013/06/magnetoshell-concept-proven-for-braking.html#more

If I understand the article correctly, this would act something like a Plasma Parachute in the upper atmosphere.

Yeah, that's the analogy we use a lot. It works reasonably well.

Quote
But if the Payload is actually in front of the Magnetized Plasma effect, wouldn't it too need some form of TPS?

It depends, but not exactly. While it's true that having the spacecraft inside the magnetoshell provides an extra level of protection versus atmospheric heating, just increasing the effective drag area means you can get the same amount of braking higher in the atmosphere, where the lower density means much less heat flux.

Instead of a ballistic coefficient of 250-500kg/m^2 that you see for capsules or the shuttle, or 25-50kg/m^2 that you get for a HIAD system, you can potentially get ballistic coefficients less than 1-5kg/m^2 with a properly designed Magnetoshell with the right bells and whistles...Potentially much less than 1kg/m^2...

Take their Mars aerocapture design. Compared to a 5m radius heatshield that you could theoretically get on an SLS-type vehicle, you could get a 20m radius magnetoshell using their design, and possibly as much as 40-50m radius magnetoshell using some reasonable tricks we've thought of since they did their paper. You're talking about an areal density somewhere between 16-100x lower than you could get with a traditional heat shield (and probably still 4-25x more than you could get with a HIAD. That means that for the same desired drag, you can do a pass where the density is 16-100x lower than you could with the traditional heatshield or 4-25x lower density than you could with a HIAD. Heat flux goes linearly with the density, so depending on the details, and the knobs twisted, even if your MAC coil is trailing on a tether, you still might not actually need TPS.

Oh, and that 20-50m radius magnetoshell can be made with a payload that fits into a 5m EELV fairing...

~Jon

Jon,

Sounds like lots of advantages there.

With such low ballistic coefficients, could this be used for de-orbiting stuff from a high-ish LEO? Does sound just what F9US would need for recovery.

Also, for Mars capture... I believe this is frowned upon for crew because of risk of atmospheric variability.

This technology sounds like you could target a middling coefficient for expected conditions, then adjust it on-the-fly to ensure exactly the required capture?

Perhaps use same trick for decreasing the landing ellipse of direct entries?

I'm wondering if an element of lift is available by shaping the magnetic field?

Cheers, Martin

Tags: aerocapture