Jessica Meir in the context of "Spacewalk"

Christina Koch (/kʊk/ COOK; née Hammock; born January 29, 1979) is an American engineer and NASA astronaut of the class of 2013. She received Bachelor of Science degrees in electrical engineering and physics and a Master of Science in electrical engineering at North Carolina State University. She also did advanced study while working at the Goddard Space Flight Center. Just before becoming an astronaut, she served at the National Oceanic and Atmospheric Administration as station chief for American Samoa.

On March 14, 2019, Koch launched to the International Space Station as a flight engineer on Expedition 59, 60, and 61. On October 18, 2019, she and Jessica Meir were the first women to participate in an all-female spacewalk to replace a down power control unit located outside of the International Space Station. On December 28, 2019, Koch broke the record for longest continuous time in space by a woman. She returned from space on February 6, 2020.

Expedition 61 was the 61st Expedition to the International Space Station, which began on 3 October 2019 with the undocking of the Soyuz MS-12 spacecraft. The Expedition was commanded by ESA astronaut Luca Parmitano, who became the third European and first Italian astronaut to command the ISS. Parmitano, along with his Soyuz MS-13 colleagues Aleksandr Skvortsov and Andrew Morgan, and Christina Koch from Soyuz MS-12, transferred over from Expedition 60. They were joined by Oleg Skripochka and Jessica Meir, who launched on 25 September 2019 on board Soyuz MS-15.