Solar "Rover"

The very obvious problem with sending anything to the Sun is that it would vaporise ages before it got near. Or would it?

Sunspots are cooler than the rest of the photosphere, at 3 800 K. This is, amazingly, actually below the triple (melting) point of some solid substances such as tantalum carbide and tantalum hafnium carbide, which have "melting" points of 4 150 K and 4 263 K respectively. And yes, everyone can use the internet and read Wikipedia, so no original idea yet.

The idea, then, is this: make a vehicle of some description _entirely_ out of one of these substances, so it's entirely mechanical, possibly a clockwork ornithopter with initially furled wings. Get as close to the sun as you can get with a conventional spacecraft, then fire the clockwork ornithopter at great speed towards a sunspot, possibly encased in a large block of frozen hydrogen. When it approaches the surface of the sun, decelerate it with a solar sail consisting of a very thin polished tungsten membrane, which will of course vaporise. The ornithopter then flies across the sunspot.

There are a few issues with this:

This device would have to be entirely mechanical. That needn't be an enormous problem as such because clearly mechanical computers are possible. However, it is a little hard to imagine how it could be powered owing to the fact that this substance is neither a conductor nor ferromagnetic, and is also very brittle, so there's no way it could be clockwork as a spring is unfeasible. Nor can it be rocket-propelled because any rocket fuel is going to be destroyed and possibly detonate. What I do have in mind, though, is a flywheel which is set in motion before launch, which articulates with the rest of the vehicle and powers it, maybe with a cam belt like a bike chain.

I'll get back to the internal workings in a bit because another pressing issue is the temperature of the solar prominences at 20 000 K and that of the corona of a couple of million K. However, temperature is not heat. The corona is practically vacuum and the chromosphere is also pretty thin, so in fact this may not be much of an issue.

Back to the internal workings then. I envisage a flywheel powering the entire vehicle, with a cam chain and camshaft transferring the energy to the flapping wings which will fly through the plasma of the sunspot. Two pinhole cameras focus the light of the sunspot onto a "retina" which consists of a moving cylinder of the stuff concerned, thereby focussing an image consisting of vaporised and non-vaporised portions, which will "click" round producing a kind of stereoscopic cine film mounted helically on a cylinder. Thin diaphragms of metal behind "fluffy" baffles record the audio of the journey onto gramophone discs via a stylus and a thin tympanic membrane of the same substance.

Given that the photosphere is made of plasma, although I imagine it being able to fly or swim through it with a kind of flapping motion, for all I know this is actually impossible because plasma is not gas or liquid, although it is a fluid.

The escape velocity of the sun at the surface of the photosphere is over 600 kps, so the idea currently fails right here because unless the probe starts at that velocity this is merely an art project involving sending a useable vehicle to the sun which will do something and then vaporise. Still, it's better than nothing.

Oh, and obviously it needs to be sent at night (groan).