Landing a craft safely on the Moon is much harder than one might expect. There have been a number of crash landings recently, with the Russian Lunar 25 being the most recent example - only yesterday. India, Israel and Japan have also had landers that suffered similar fates over the past few years.

Space is difficult. It is dangerous and uncompromising. Despite leaps in technology since the Apollo missions, we are learning just how much a tiny miscalculation can affect an entire project. Voyager 2, which has pushed out to edge of our solar system since its launch in the 1970's, may be lost to us as a result of a faulty command signal from Earth. NASA is scrambling efforts to repair the bungle.

Of course, none of these missions are manned. Space is especially toxic to biological life forms, so robotic expeditions are de rigueur for the time being. It's romantic and exciting to think of humans aboard vessels to the Moon and Mars, but the risks are great and the payoff not necessarily worth it. AI is coming along rapidly and most of the decisions astronauts make will be replicated by machines.