The sun is dying: the impact on Earth doesn't need to be elaborated, so a ship, the unfortunately-named Icarus is sent to deliver a bomb that will hopefully re-ignite our star. It vanishes without trace. Seven years later, the equally poorly-labelled Icarus 2 follows the same path, with Kapa (Murphy) the man in charge of the bomb this time. But as it approaches the target, a signal is picked up; it's a distress beacon from the original ship. Should they investigate? And if they do, what will they find on board the marooned craft? You can tell it was a Brit who directed this, since one of the main themes is the hellish destructive power of the sun, something easily forgotten in London - since moving here to Arizona, it's something of which I have enormous personal experience. We don't need to fly inside the orbit of Mercury to experience solar fury: just try opening your car door in a Phoenix August, without the benefit of oven-gloves.
That said, this is generally effective, with the perils of space-flight making for enough tension, as the crew struggles to cope with all the threats, as they boldly go where, etc. There's no need for alien threats or other fabricated menaces. Thanks to the sun, life on-board is quite tense enough as it is, with a good chance of it being short too, and the film doesn't short-change that. It's generally gloomy, with a series of fairly harrowing deaths; the worst are the ones where the people know it's coming, and there's no way out. [I wonder why horror films don't make more of this: it's not mortality I fear so much, as an awareness of my mortality] The film shift gears in the final reel, changing from hard science-fiction to something closer to a bad slasher. It's nowhere near as effective, degenerating into something that's little more than a confusing mess. Despite some stunningly-rendered effects, which do the job of cinema, taking you places you can't go yourself, the disappointing end sadly mars a very promising and well-grounded effort.