(CNN) During Friday's historic all-woman spacewalk from the International Space Station, a female voice can be heard speaking to astronauts Jessica Meir and Christina Koch from Mission Control.
It's NASA astronaut Stephanie Wilson and she's acting as CapCom, or Capsule Communication, at Johnson Space Center in Houston.
CapCom is the astronaut who on Earth who communicates with crew members on the craft. Wilson took over Friday morning just as Koch and Meir were beginning their spacewalk.
NASA tweeted about Wilson's role. "Who's talking to the astronauts from Mission Control during today's #AllWomanSpacewalk? That's astronaut Stephanie Wilson, who has spent 42 days in space over 3 spaceflights! https://go.nasa.gov/33Ky20i"
She's been issuing instructions and staying in touch with both women during their six-hour walk to install a power controller. Wilson's voice is a familiar one for Koch and Meir. They all know each other well.
Wilson was selected as an astronaut in April 1996 and flew three shuttle missions that assisted with assembling the space station and delivering crews, NASA says. She was on board for missions STS-121 in 2006, STS‑120 in 2007 and STS-131 in 2010.
Wilson was the second African American woman to go into space after Mae Jemison.
She received her bachelor's degree in engineering science from Harvard University in 1988 and her master of science in aerospace engineering from the University of Texas in 1992.
Wilson tweeted about acting as CapCom on October 7, days after they were announced. "As part of the Houston MCC team, it is a pleasure to work with @Astro_Christina, @AstroDrewMorgan, @astro_luca and @Astro_Jessica for this series of spacewalks to upgrade @Space_Station batteries!"
Wilson serves as the Astronaut Office Mission Support Crew Branch Chief and was on the astronaut selection boards in 2009, 2013 and 2017. Koch and Meir were selected for the astronaut class of 2013.
She remembers interviewing an astronomer in school.
"I grew up looking at the night sky and wondering what was out in the heavens," Wilson said during a TEDxDunedin talk in 2012.