The 2020s has seen a revival of the “Apollo spirit”. The US and China are seemingly in a race to send humans to the moon by the end of the decade – and thereafter, perhaps, even to Mars. Nasa astronauts have just returned from a 10-day journey looping around the moon. Although they arrived back safely, Nasa accepts that the lack of data makes it impossible to quantify the risks involved – this represents only the second launch for the Artemis system and the first to carry astronauts. To date,…