Magnetic heat shield

[Dr Mordrid]

This goes along with the work being done in the US and Europe on a magnetoplasma shield for spacecraft that would protect against the solar wind, solar flares and other particle radiations.

Shields up, Scotty

http://www.physorg.com/news178442290.html

Superconductor magnet spacecraft heat shield being developed

(PhysOrg.com) -- European space agencies and an aerospace giant are developing a new re-entry heat shield that will use superconductor magnets to generate a magnetic field strong enough to deflect the superhot plasma formed during re-entry of returning spacecraft. They plan to test the new technology by attaching a test module to a missile and using a Russian submarine to fire it into space.

As spacecraft re-enter the Earth's atmosphere at high speeds super-hot temperatures are produced through friction. Traditional heat shields use temperature-resistant ablative coatings that burn off on re-entry, or tough insulating materials, such as the tiles used on the space shuttle. If the new magnetic shielding is successful it could be more reliable and make the craft lighter and easier to re-use, since it would reduce or eliminate the need for other shielding materials.

The project is being run cooperatively by the European Space Agency, EADS Astrium, and the German aerospace center, DLR (Deutschen Zentrums for Luft- und Raumfahrt). The idea is to use a superconducting coil at front of the craft to generate a strong magnetic field projecting beyond the front of the craft.

The scientists are currently assessing the superconducting coil's performance, and have not yet finalized the technical details of exactly how they will fit it into a Russian "Volan" escape capsule for the test. Also uncertain at this stage are the modifications that will be needed to the trajectory to compensate for the deflected air. Telemetry data recovery will also present challenges because the ionized gases that will form around the craft will block radio signals.

The Volan and its magnetic heat shield would be launched into a suborbital trajectory from a Russian submarine at sea. The missile, a modified ballistic missile called Volna, would re-enter the Earth's atmospher at Mach 21 and come back to Earth in the Kamchatka peninsula, a remote region of the Russian Far East.
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[VJ]

Maybe a stupid question, but what is preventing people to slow down in space (e.g. with forward facing rockets) and make a relatively slow re-entry?
Is it the storage for the amount of energy needed to slow down? Or would slowing down simply take too long?

Jörg

[Dr Mordrid]

Not a stupid question at all.

Orbital re-entry is done at about mach 20+, and hitting the atmosphere that fast generates a ton of heat and hot plasmas. IF you could somehow get re-entry speed down to say mach 3.5-4.0 you could come in like SS1 or SS2, with no more thermal protection than a special iron based paint (the rust colored stuff you saw on SS1's nose and leading edges).

Fuel mass is the problem; using a burn to get down to mach 3.5-4.0 would require the equivalent of another 2nd stage attached to the vehicle just to do the re-entry burn since it is the 2nd stage that does orbital insertion. Figure triple the vehicle mass, which would then require a much larger booster to get all that stuff up there. $$$$$$

This new method of redirecting the hot plasmas away from the vehicle is a novel approach, but so is an inflatable ballute (balloon-parachute) like was used in the movie 2010 to decelerate the Alexei Leonov into Jovian orbit.

A prototype ballute re-entry system was tested by NASA earlier this year after being launched from the Wallops Island spaceport in Virginia. It was called IRVE - Inflatable Re-entry Vehicle Experiment. IRVE was made of a silicone-coated fabric and the word used to describe its performance was "spectacular", so I think we'll be seeing more of this technology. It's also cheap and light weight.

(large image....)

[VJ]

Ok, so the problem is with the storage of the required energy to achieve it...

IF you could somehow get re-entry speed down to say mach 3.5-4.0 you could come in like SS1 or SS2, with no more thermal protection than a special iron based paint (the rust colored stuff you saw on SS1's nose and leading edges).

So if I understand:
SS1 or SS2 don't reach such high speeds, so don't need to slow down. And the reason they don't reach the high speeds is that they don't require it (no specific orbits, ...).

Interesting stuff!
Still, I find the ablative heatshield like the Soyuz capsule uses a very clever option: less possible issues than with ceramic tiles... The ballute is a nice idea!

Jörg

[TransformX]

Will that magnetic shield stop a hand held stone or a bullet from hitting the ship as well or is it only good for plasma?

[Evildead666]

This looks cool

I suppose that since its magnetic, at least metallic objects should be repulsed.
Wouldn't want to attract all that space debris would they ?

"Why is that satellite coming towards us ?"

edit : I'm most interested as to how they get a superconductor to be right next to superhot gases and plasma, whilst staying superconducting. ?
I was under the impression superconducting increased and was achieved around absolute zero ?

[Dr Mordrid]

VJ: SS1 and SS2, because of their high drag configuration (rotated wings up), start slowing down very high up in the atmosphere. This causes them to lose a lot of speed before reaching the thicker parts further down.

Example: SS1 climbed to 367,360 feet and was significantly decelerated before reaching the altitudes at which Columbia burned up - about 250,000 feet - that its surface only achieved a temperature of only 200F. In fact, it got warmer going up than coming back down

Here's another piece of SS1 trivia:

Rate of climb for F-18: 50,000 ft/min

Rate of climb for SS1: 82,000 ft/min

TX & 666: no, it won't repulse metal objects - it's a re-entry tech and not a shielding tech like in Star Trek.

As for superconductivity: the windings can incorporate coolant channels within the cable or the coolant can surround it, and they can be quite small and below the skin of the vehicle. The field will extend quite some distance beyond the spacecrafts skin. Superconducting cables use the least coolant and have a coolant pipe in the center spiral wound with the superconducting ribbons then overlaid with insulation and protective layers. Dunno for certain which way they're going, but it looks like cable based on the drawing.

[Elie]

it's a re-entry tech and not a shielding tech like in Star Trek.

Technically this should allow for probes or unmanned space craft to get closer to the sun for research purposes.

Next up...true Metaphasic shielding

[KRSESQ]

Cool factor aside, one wonders if it would really be worth it to replace a 1,200 lb heatshield with a 2,000 lb magnet and support equipment.

On an interplanetary spacecraft it would be essential. On a re-entry vehicle I can't see it adding anything but extra weight.

Kevin

[Dr Mordrid]

Especially with thermal systems like SpaceX's PICA-X which can handle re-entries at speeds 2x that of normal orbital velocities - about 29,500 mph. Good argument for Dragon being far more than LEO-capable, isn't it? They could have gone with far less expensive/complex options.

As for interplanetary: M2P2 (mini-magnetospheric plasma propulsion), a surrounding field laced with low temperature plasma for spacecraft propulsion that can double as an artificial magnetosphere. The solar wind intercepts the field and pushes on it like wind on a cloth sail. Also known as a "MagSail". NASA ran a series of very successful vacuum chamber tests in 2000-2001 (the field was created, injected with plasma and inflated as predicted) and work continues both here in the US and in the UK.

A flight MagSail would have a field about 30km in diameter but only use a few kW of power and a few kg of gas to provide the plasma.