NASA's Regolith Excavation Challenge invited teams to build machines for digging mock moon dirt, or regolith, in a competition held in a one-ton sandbox on Saturday.
But all the teams fell well short of the winning requirement of 330 pounds (150 kilograms) of regolith deposited in a container in 30 minutes, and no one claimed the $250,000 (185,377 EUR) purse.
An excavator built by Technology Ranch of Pismo Beach did the best, collecting just over 143 pounds (65 kilograms) in half an hour. All the other machines broke down while digging.
The other three teams were from Berkley, Michigan; Rolla, Missouri; and Rancho Palos Verdes.
The prize rolls over to next year's competition, which will be worth $750,000 (556,132 EUR).
One hundred years ago today ended the most grueling of wars involving disgusting conditions for soldiers and at least 17 million deaths. We learnt nothing.
Russia has been developing an energy module on the basis of the megawatt-class nuclear power plant since 2010. The spaceship needs neither sunlight nor solar batteries