Space isn't having a great few months -- from the exploding mishaps of Orbital Science's Antares rocket, to the terrible tragedy of Virgin Galactic's test flight, and the yay -but-oh-shit rollercoaster that's been the ESA's comet landing , things aren't going entirely to plan. This isn't without precedent, though: if you shoot enough things into the sky on top of volatile rockets, some of them are going to let you down. Or blow up.