Sunday marked the second time Kathy Sullivan made history.

Nearly 25 years after she became the first US woman to walk in space, Sullivan became the first woman to ever reach Challenger Deep, the deepest point in our planet’s oceans. She’s the only person ever to do both.

Challenger Deep lies nearly 7 miles (11 kilometres) below the Pacific Ocean’s surface within the Mariana Trench about 200 miles (300 kilometres) southwest of Guam.