One of the many excellent ambient tracks from Sunshine.
Right from the myths of Prometheus and Icarus (and probably earlier) stories have tinkered with the idea of visiting or approaching the Sun. It's a long-standing mythological motif that the eagle is the only creature that can fly to the sun. Seeing Sunshine, which recently premiered on UK television, prompted me to look for more examples.
There are a few literal landings on the Sun in literature. For instance, Satan in Milton's 1667 Paradise Lost lands there: being a kind of supervillain, he's unharmed but finds it, unsurprisingly, "beyond expression bright"
So wonderously was set his station bright.
There lands the Fiend, a spot like which perhaps
Astronomer in the sun's lucent orb
Through his glazed optick tube yet never saw.
The place he found beyond expression bright,
Compared with aught on earth, metal or stone;
Not all parts like, but all alike informed
With radiant light, as glowing iron with fire;
Cyrano de Bergerac's 1662 Histoire comique des États et Empires de la Soleil (Comical History of the States and Empires of the Sun) is more of an allegorical/satirical Sun. The narrator, Dyrcona, travels there in a flying machine powered by solar reflectors and finds it to be a world of "burning snowflakes" and abundant plant life; he is captured and put on trial by sentient birds (description from p.21, Different engines: how science drives fiction and fiction drives science, Mark Brake & Neil Hook, Palgrave Macmillan, 2008). Sydney Whiting's 1855 Heliondé: or, Adventures in the sun - online in full at Google Books - is in the same fanciful vein, though with less philosophical subtext and considerably more weird: Science-fiction, the early years describes it as
Essentially an erotic dream in very veiled terms, told as a collection of extraterrestrial curiosities with, very oddly, a heavy increment of mid-nineteeth-century Classical scholarship.
(An example of the much-complained-of weird metadata: Google Books classifies it as "political science").
I can't find anything much about it, but Hyman Kaner's 1946 Llandudno-published The Sun Queen, in which a couple are transmitted to a planet inside the Sun, sounds to be much the same. Surprisingly, older fantasies of this form were not necessarily as far-fetched in their time as they seem now; a number of perfectly serious books argued from the (comparatively) darker appearance of sunspots that the Sun might have a cooler inhabitable core. See, for instance, The complete works of Thomas Dick and Popular astronomy, both referring to astronomer William Herschel's "habitable sun" theory.
Mostly, however, now that we know the Sun is a giant nuclear fusion reaction, fiction is realistic about its nature. Any creatures there are assumed to be very different from any life we know (this Technovelgy article mentions several works tackling the idea). But this doesn't preclude a variety of treatments of the theme of humans visiting: the lyrical, as in Ray Bradbury's 1953 The Golden Apples of the Sun; the gently comic, as in the 1985 Journey to the sun in a glacier ship; the poetic, as in Edwin Morgan's Golden Apples (which actually refers to the Bradbury story ); the epic, as in Samuel R Delany's 1968 Nova; and the ludicrous, as in this Weekly World News story, which recycles the old joke about the safest way to send a mission to the Sun.
Yes, I know Nova isn't about the Sun, but the Promethean myth is central to its plot ...
We have to go to the rim of chaos and bring back a handful of fire
... to collect a precious superheavy element direct from an exploding nova, an aim achieved at great cost.
Which brings me back to Sunshine, which recently premiered on UK television. If you haven't seen it, do (I'm hoping it'll turn up some time at the local independent cinema). Despite any number of technical/scientific implausibilities and overt allusions to other SF movies, it's a vastly impressive film, one of my favourites from the last few years, helped along by stunning visuals (informed by the latest SOHO images) and a moving ambient soundtrack by Underworld and John Murphy. One of its unusual elements is its reversal of the Prometheus myth, it being about a mission to take fire to the Sun. I thought I might be the first to think this, but I see Walter Chaw's review at Film Freak Central beat me to it in describing how the whole voyage of the Icarus II appears to be a conception metaphor:
Visually, the Icarus II looks like a sperm cell (its giant spherical "payload" trails a long ship behind it), while the sun, in scale and shape, looks like the egg, making the inevitable union of the two, giving nothing away, something clearly meant to evoke either a successful or unsuccessful act of reproduction.
Jumping from the sublime to the commercial, seeing Sunshine finally explained to me what the Carling "Space" advertisement is alluding to. The music from the ad is actually part of the Elegia movement from Christopher Rouse's Flute Concerto, to which the main theme from Sunshine, John Murphy's Adagio in D minor, has something of a resemblance.