McArthur, who has a doctoral degree from Scripps, will be accompanied by NASA commander Shane Kimbrough and international partner astronauts Akihiko Hoshide of Japan and Thomas Pesquetlauis of France on the 3:11 a.m. Pacific time launch from the Kennedy Space Center in Florida.
It will be her first trip to the International Space Station, where she will conduct research into medical technology, human health and materials over a six-month period.
In 2009, she logged nearly 13 days in space when she participated in the final Space Shuttle mission to service the Hubble Space Telescope.
Prior to becoming an astronaut, McArthur was trained as an oceanographer and engineer. She was born in Honolulu and grew up in Silicon Valley.
The Crew-2 mission will be the third flight of a SpaceX Falcon 9 rocket and Crew Dragon capsule carrying humans.