The first woman on the moon

There are currently 12 women in NASA’s active astronaut corps. One of them will likely be the first woman to walk on the moon.

Dr. Serena Auñón-Chancellor

Current age: 43 Specialty: Internal medicine, aerospace medicine Spent two months living on the ice in Antarctica while searching for meteorites. Also served as an aquanaut in an underwater lab. Days in space: 197

Tracy Caldwell Dyson

Current age: 49 Specialty: Chemistry Worked as an electrician while attending college. Has three space walks under her belt, and is conversational in American Sign Language and Russian. Days in space: 188

Jeanette Epps

Current age: 48 Specialty: Aerospace engineering Before joining the astronaut corps, Epps worked for seven years as a technical intelligence officer at the CIA. Days in space: 0

Christina Koch

Current age: 40 Specialty: Electrical engineering Has worked at remote science bases in Antarctica, Alaska and Greenland and is now poised to set the record for longest single spaceflight by a woman. Days in space: 128 (as of July 20)

(When she returns from the International Space Station next year, she’s expected to have 328 days in space.)

Nicole Mann

Current age: 42 Specialty: Mechanical engineering/test pilot A lieutenant colonel in the Marine Corps, she has accumulated more than 2,500 flight hours in 25 types of aircraft. Days in space: 0

Megan McArthur

Current age: 47 Specialty: Oceanography As part of the final Hubble Space Telescope repair mission, McArthur operated the robotic arm that brought the telescope into the shuttle’s cargo bay. Days in space: 13

Anne McClain

Current age: 40 Specialty: Aerospace engineering A senior Army aviator, she has logged more than 2,000 flight hours in 20 different rotary and fixed-wing aircraft. Days in space: 204

Jessica Meir

Current age: 42 Specialty: Biology/physiology Trained high-flying geese to fly in a wind tunnel so scientists could better understand how the birds survive in lower-oxygen conditions. Days in space: 0

(She is scheduled to depart for the International Space Station in September and remain there until spring.)

Kathleen Rubins

Current age: 40 Specialty: Microbiology Once headed a lab of 14 researchers studying viral diseases and was the first person to sequence DNA in space. Days in space: 115

Shannon Walker

Current age: 54 Specialty: Space physics An astronaut and aquanaut, she commanded the NEEMO 15 underwater exploration mission and helped design and construct robotic hardware for the International Space Station. Days in space: 163

Sunita Williams

Current age: 53 Specialty: Test pilot The first person to run a marathon (2007) and a triathlon (2012) in space, she likes to work on cars and planes in her spare time and has logged more than 3,000 flight hours in 30 aircraft. Days in space: 322

Stephanie Wilson

Current age: 52 Specialty: Aerospace engineering Worked as an engineer on the Titan IV rocket and the Galileo spacecraft. In space she controlled the robotic arm on the International Space Station over a 15-day resupply mission. Days in space: 43