 What main motivation did Antler Park have to leave the lens in the barracks?
He could be excused this time, however, for this was only our third day on Jupiter's Eighth Moon, and the country was still strange to us. And then I was shaking hands with Antlers Park, the manager of I. V. himself. Antlers Park flicked the ash from his cheroot and shrugged. It's no use to the people of Earth but of untold value on Mars. So now here we were at the outer reaches of the Baldric, four travelers on foot with only the barest necessities in the way of equipment and supplies. Apparently these adjustments moved planes or fins on the kite and accounted for the car's ability to move in any direction.
 He knew the value of this spot for Acoustix, and wanted to run the Jimmy Baker out.
 He didn't fully understand the effects of the infra-red rays and wanted to see what it was capable of.  He knew the value of this spot for Acoustix, and wanted to run the Jimmy Baker out.  He was afraid of Grannie Annie discovering his plot and tried to get rid of her.  He had struck a large load of Acoustix and wanted to hide the evidence.