Five decades on from the last of the Apollo missions, the Moon is once again a target for space exploration. But Nasa no longer has lunar exploration to itself.

The reasons for going to the moon vary: from scientific knowledge and technological advances to the prospect of accessing potentially useful lunar resources and political or economic value.

But in such a crowded field, the big question is who will become the next major global player in the next phase of lunar exploration. It will no longer be the sole preserve of national space agencies; commercial companies also want a piece of the lunar action.