Three companies are to build lunar vehicles on behalf of the US space agency NASA in future. The private space companies Intuitive Machines, Lunar Outpost and Venturi Astrolab have been selected for the contract worth a total of $4.6 billion, NASA announced at a press conference on Wednesday. Each of the three companies will now work on a prototype for a year before deciding which vehicle will be sent to the moon, how and when. The companies have all been working in similar areas for some time. Intuitive Machines achieved the first unmanned commercial landing on the moon in February. In future…