SpaceX made an early holiday delivery to the International Space Station on Sunday, dropping off super muscular "mighty mice," pest-killing worms and a smart, empathetic robot. The capsule holds 2,720 kilograms of supplies, including 40 mice for a muscle and bone experiment. Eight of them are genetically engineered with twice the normal muscle mass—and so are considered "mighty mice."' There also are 120,000 roundworms, or nematodes of a beneficial variety that are part of an agricultural study aimed at controlling pests. (Photo/Agencies)
