Next week shares go on sale in Musk's Texas-based SpaceX, a company that is planning to colonise Mars and put artificial intelligence (AI) data centres in space. It is set to be the largest ever public sale of shares and will make SpaceX one of the US's top ten largest listed firms. But for those who invest, what exactly will they be buying and what are the risks? SpaceX is currently owned by Musk and other private investors. On 12 June millions of new shares in the company will go on sale and