Into the sun [Spaceships]

[Pragmatic]

Originally Posted by ericbsmith

In Sundiver (the 1st Uplift book) IIRC it was also a special type of shield.

Shields, a temporal field (to slow the intake of heat), and a cooling laser to pump the heat out of the space between the outer hull and the inner hull (somehow letting the space get hotter than the area outside the ship, thus being able to cool the ship).

Fnord follows.
And they still almost got crushed (mostly due to sabotage of the alien superscience devices).

[Ragitsu]

Are all forms of sun shielding, to us, superscience, or is any of it possible (no matter how theoretical or rare material intensive)?

[ericbsmith]

Originally Posted by Ragitsu

Are all forms of sun shielding, to us, superscience, or is any of it possible (no matter how theoretical or rare material intensive)?

Superscience. The temperature of the Photosphere is 4500K to 6000K. The outermost layer of the sun, the Corona, reaches millions of degrees Kelvin. Those kinds of temperatures turn any real matter into plasma in short order. You need superscience to dissipate that kind of heat without the ship disintegrating.

[jeff_wilson]

Originally Posted by lexington

That's why the shields are different sizes. There's a thin field of frozen time between the ship and the outside world.

Ah, clever. Though with no access through the field, there's no way to ensure synchronization or to take advantage of the unique circumstance of being inside the sun or to check to see if you actually made it there.

[alaph]

Originally Posted by ericbsmith

Superscience. The temperature of the Photosphere is 4500K to 6000K. The outermost layer of the sun, the Corona, reaches millions of degrees Kelvin. Those kinds of temperatures turn any real matter into plasma in short order. You need superscience to dissipate that kind of heat without the ship disintegrating.

Look at it this way, at these temperatures, pressures, ect the electrons are literally stripped from the protons and neutrons thus forming the plasma. This happens at a basic level and while some materials may last a few micro seconds longer than other (for example a planet would probably last a few minutes before it became complete plasma) nothing made of electrons, protons, and neutrons would be able to survive the trip....

But if you use supersciencium then you get another huge problem... how much thrust is required to escape the gravitational pull of a sun? Once you are in that close you are kinda screwed. Unless of course you use the sun as your source of propulsion right?

Disclaimer: I'm no scientist so this may not be completely accurate but I think I've got the basic idea of fission down right?

[jeff_wilson]

Originally Posted by ericbsmith

Superscience. The temperature of the Photosphere is 4500K to 6000K. The outermost layer of the sun, the Corona, reaches millions of degrees Kelvin. Those kinds of temperatures turn any real matter into plasma in short order. You need superscience to dissipate that kind of heat without the ship disintegrating.

This isn't entirely accurate; there are un-ionized gasses present in the photosphere, including most famously helium, and while the corona is in the millions of Kelvins, it's so thin there's very little heat transfer and multiple comets have been photographed surviving its entire depth to crash and vaporize on the photosphere.

This still presents a problem, though the prospects of sublimating or gaseous spacecraft are not entirely beyond the realm of believability.

[lwcamp]

Originally Posted by ericbsmith

Superscience. The temperature of the Photosphere is 4500K to 6000K. The outermost layer of the sun, the Corona, reaches millions of degrees Kelvin. Those kinds of temperatures turn any real matter into plasma in short order. You need superscience to dissipate that kind of heat without the ship disintegrating.

The corona is so diffuse that heat transfer from coronal gases to a spacecraft will be orders of magnitude lower than passive radiation of heat from the spacecraft. The big problem will be the very high flux of radiant heat from the solar photosphere. Heroic engineering with believable science could protect a spacecraft in the corona. Nothing will protect a spacecraft in the photosphere or deeper. I suspect that the chromosphere is also non-survivable, but have not worked the numbers.

Luke

[lwcamp]

Originally Posted by Ragitsu

Are all forms of sun shielding, to us, superscience, or is any of it possible (no matter how theoretical or rare material intensive)?

You can use shielding to get close to the sun, likely a thin reflective layer over a refractory graphite heat shield that shadows the sensitive equipment. Keep the graphite shield between you and the star. Have a large radiator fin pointing away from the sun in the shadow of your heat shield, to radiate away the heat the shield absorbs.

Once within the solar photosphere the temperature is so high that all matter will be first melted and then vaporized, ending up as a sparsely ionized plasma.
photosphere temperature: 5778 K
melting point of tungsten (the most refractory metal): 3695 K
sublimation temperature of graphite (the most refractory non-metal): ~ 4000 K

It is conceivable that a spacecraft with a thick hull made out of a highly refractory substance could survive trips into the upper photosphere of a cool M-class star, whose temperature may only be in the 3500 K range. You would need some sort of heat pump to keep the interior cool. The deeper you go, the higher the temperature, so stay shallow.

Luke

[RogerBW]

Originally Posted by RyanW

The Sun Crusher, even more than the Death Star, is only available by special order from Plot Devices R Us. If you honestly need stats for it...

...then you may be playing GURPS Lensman. One could regard that as a cascade of plot devices (each battle is a contest of Science! skills), but actual stats would be more fun.

This isn't to say I disagree with the general tenor of the thread: those stats will have nothing whatsoever to do with reality, and as long as they're consistent with each other it doesn't really matter what the numbers are.

[gjc8]

Originally Posted by Ragitsu

Are all forms of sun shielding, to us, superscience, or is any of it possible (no matter how theoretical or rare material intensive)?

That depends exactly what you mean by superscience. I don't think it violates any fundamental physical laws (unlike, for example, ftl travel or reactionless drives).

That said, you're going to need some absolutely fantastic materials to pull it off (at least to get closer than the corona). You need hull material that has good material properties at very high temperatures, and either incredible heat sinks or extremely effective heat pumps. Propulsion isn't going to be trivial, but easy compared to heat dissipation and material science.

It MIGHT be possible at TL 12: Some sort of exotic matter hull, a black hole as heat sink, etc.