katherine megan mcarthur (born august 30, 1971) is an american oceanographer and a national aeronautics and space administration (nasa) astronaut. she has served as a capsule communicator (capcom) for both the space shuttle and space station. megan mcarthur has flown one space shuttle mission, sts-125, where she served as mission specialist in repairing the hubble space telescope. mcarthur has served in a number of positions including working in the shuttle avionics laboratory (sail). she is currently in space as the commander of the nasa spacex crew-2 mission to the iss. she launched on 23 april 2021.