Solar Probe

[RobA]

Thinking about the upcoming Superman movie cast my mind back to the dire Superman 4(?), where Mr Muscles threw all the nukes into the sun.

That got me thinking about the following:

Assuming we had the tech to send a probe to land/impact the sun (and it and it's instruments could take everything the sun could throw at it), then

a) Would a free-drop from a craft work, or would all the stuff (pardon the technical terms) coming from the sun require a powered descent? Any difference if you're aiming for a sunspot?

b) What mysteries would you look to resolve?
This includes would you aim for "normal" surface, sunspot, or pole? What instruments would you have on board?

[Ilya]

a) Would a free-drop from a craft work, or would all the stuff (pardon the technical terms) coming from the sun require a powered descent? Any difference if you're aiming for a sunspot?

Free drop would certainly work. Anything falling toward the Sun from a great distance impacts at 600 km/sec. "Stuff coming from the sun" -- light pressure and pressure from solar wind, -- is completely overpowered by gravity.

Aiming for a sunspot may be a bit tricky because of the magnetic fields involved. There is no way they would fling your craft away from the Sun, but they may well cause it to hit in a very different place.

[Jeff Root]

A probe all the way down to the photosphere would have to be
very massive, with almost all of that mass devoted to carrying
away heat. Otherwise the entire probe would be vaporized, and
the resulting vapor would be blown away by the Sun's
light pressure or solar wind. With a good design, only the
part of the probe that is intended to vaporize would vaporize
before it got very deep into the photosphere.

Windows for observation instruments would need to have a steady
flow of cold gas across their surfaces to prevent them from
melting or heating to the point that the radiation they would
give off would make them opaque. I wonder how telemetry could
be sent from such a probe, or detected on Earth.

-- Jeff, in Minneapolis

[IsaacKuo]

I wonder how telemetry could
be sent from such a probe, or detected on Earth.

Maybe you do something like Shoemaker-Levy 9. Just bang something big and heavy onto the Sun and observe the consequences from afar. Maybe if you practice some asteroid deflection technology on an outer solar system planetoid (outer rather than inner to minimize the energy cost of deleting it's orbital velocity)...

[Wolverine]

On a related note, RobA, you might find this interesting.

[Swift]

David Brin wrote a novel, Sundiver (I think that was the name) that talked about a manned exposition to the sun (they didn't land, but got close). I don't recall the details but the craft had a mirror-like surface (to reflect away as much energy as possible) and had a system that took the remaining heat, pumped the energy to a laser, aimed the laser away from the sun, and used that as a "refrigerator".

[NEOWatcher]

Maybe you do something like Shoemaker-Levy 9. Just bang something big and heavy onto the Sun (snip)

Careful, so you don't disturbe the astrological harmony.

David Brin wrote a novel, Sundiver (I think that was the name) that talked about a manned exposition to the sun (snip)

What are they going to expose to the sun? (ow, ow, ow, ow)

[IsaacKuo]

David Brin [...] had a system that took the remaining heat, pumped the energy to a laser, aimed the laser away from the sun, and used that as a "refrigerator".

The heat rejection laser concept is a neat little idea which unfortunately can't possibly work. It violates the laws of thermodynamics.

[George]

On a related note, RobA, you might find this interesting.

Nice. Thanks.

I sent the chairman a request for the addition of one special instrument. Care to guess its purpose?

[Swift]

The heat rejection laser concept is a neat little idea which unfortunately can't possibly work. It violates the laws of thermodynamics.

I understand and it has been a while since I read the book, but I recall it sounded logical and I might just be explaining it badly. It might not have been for heat rejection, but for higher frequency energy, like x-rays or UV. It also was science fiction.

[Swift]

Maybe you do something like Shoemaker-Levy 9. Just bang something big and heavy onto the Sun and observe the consequences from afar. Maybe if you practice some asteroid deflection technology on an outer solar system planetoid (outer rather than inner to minimize the energy cost of deleting it's orbital velocity)...

How big an object would you have to drop in to have a noticeable effect. Comets regularly drop into the sun, do they have an effect that we can measure?

[IsaacKuo]

How big an object would you have to drop in to have a noticeable effect. Comets regularly drop into the sun, do they have an effect that we can measure?

I have no idea. I figure if you just throw Jupiter at the Sun, there'll be some visible effect.

[Wolverine]

I sent the chairman a request for the addition of one special instrument. Care to guess its purpose?

Is it bigger than a breadbox?

[George]

Is it bigger than a breadbox?

It could be made, probably, close, especially since it will become toast.

[Added...Better hint: my signature suggests, possibly, my only real contribution for all you scientists]

[Kaptain K]

Comets regularly drop into the sun, do they have an effect that we can measure?

Well, for one thing, GLP goes off-scale on the woo-woo meter!

[ZaphodBeeblebrox]

I understand and it has been a while since I read the book, but I recall it sounded logical and I might just be explaining it badly. It might not have been for heat rejection, but for higher frequency energy, like x-rays or UV. It also was science fiction.

It WAS, For Heat Rejection ...

And Yes, It Doesn't Work ...

Darn It!