I am stranded on Mars. The fuel tanks on my return vessel ruptured, and no rescue team can possibly reach me before I run out of food. (And, unlike Matt Damon, I have no potatoes.) Luckily, my ship features a teleporter. It is an advanced bit of gadgetry, to be sure, but the underlying idea is simplicity itself: the machine scans my body and produces an amazingly detailed blueprint, a clear picture of each cell and neuron. That blueprint file is then beamed back to Earth, where a ‘new me’ is constructed using raw materials available at the destination site. All I have to do is step in, close my eyes, and press the red button…

The rest here.