A pair of spacewalkers successfully tackled a hefty tank removal job at the international space station Tuesday as their crewmates unloaded comedian Stephen Colbert’s namesake treadmill for all “those famously fat astronauts.” The only concern Nicole Stott and Danny Olivas had about mass — everything is weightless up there, after all — involved the huge ammonia tank they needed to disconnect. They held the freed 1,300-pound tank steady until a robot arm grabbed it.
