Kathryn Sullivan became the first American woman to walk in space on October 11, 1984, during the space shuttle Challenger's thirteenth flight. She left the airlock with the astronaut Dave Leestma and spent about three and a half hours outside testing a system meant to refuel satellites in orbit. She was not the first woman in the world to do it: Svetlana Savitskaya had stepped outside a Soviet station three months earlier. But the first for America was hers.
She came through geology. Sullivan had studied the seabed. She joined NASA in 1978 in the first astronaut class that included women, a group that also produced Sally Ride, who flew first. The agency had spent the decade before arguing about whether women belonged in the corps, and the argument had been settled partly by the women of that 1978 class, who were picked on their records and flew on their records.
The spacewalk itself was work. The crew carried out a transfer of hydrazine fuel between two tanks through the equipment Sullivan and Leestma were testing, which was a step toward the idea, already current then, of refuelling and repairing satellites in orbit rather than letting them run out and decay. The experiment produced leaks, and the two of them worked in the cold of the payload bay to finish the job, which is what an engineering test outside a spacecraft usually comes to.
She flew twice more, once as a mission specialist on the mission that deployed the Hubble Space Telescope, and she went on to become the administrator of the National Oceanic and Atmospheric Administration, the first woman and the first astronaut to hold that post. In June 2020 she became the first person to have walked in space and reached the deepest point of the ocean, which is a record the way she phrased it: a person who has been to the highest work a human does and the lowest place a human can go.