First person to visit space and the deepest point on Earth

On 5 October 1984, Dr Kathryn Sullivan (USA) was one of seven astronauts aboard the Challenger Space Shuttle to launch from the Kennedy Space Center in Florida, USA, as part of NASA’s STS-41-G mission. Almost 36 years later, on 7 June 2020, Sullivan also reached the deepest known point in Earth's oceans, the Challenger Deep at c. 10,934 metres (35,872 feet). She made the descent in the DSV Limiting Factor, piloted by fellow American Victor Vescovo, an explorer and retired naval officer who has now journeyed to the Challenger Deep more than any other individual: eight times as of 26 June 2020.

At the time, STS-41-G’s seven-strong crew represented the joint most people working on a Space Shuttle mission (STS-9 in 1983 also had a crew of seven but with an additional pressurized lab module, whereas on STS-41-G the astronauts were restricted solely to the crew compartment). STS-41-G's crew included two female astronauts: Sullivan and Sally Ride. During the eight-day mission, Sullivan would become the first American woman to perform an extra-vehicular activity (EVA), aka spacewalk, on 11 October. The first woman to perform a spacewalk was cosmonaut Svetlana Savitskaya (USSR), just a few months before on 25 July 1984 .

The Challenger Deep is situated at the south-western end of the Mariana Trench, almost 11 km (6.7 mi) beneath the surface of the Pacific Ocean, and is approximately 400 km (250 mi) south-west of Guam. Sullivan visited the "Eastern Pool" at the bottom of the Challenger Deep at c. 10,934 m (35,872 ft) –with a deviation of +/- 3 m at 1-sigmaor +/- 6 m at 2-sigma – and spent approximately 1.5 hr exploring the seafloor with Vescovo.

Sullivan has also covered the greatest vertical extent by an individual (within Earth's exosphere) – travelling a total of 622.085 km (386.546 mi) between her highest and lowest points. Astronauts that took part in missions to the Moon have travelled a greater distance overall, but ventured beyond Earth's atmosphere.

Following the successful dive to the Challenger Deep, back on the surface on board the support vessel Pressure Drop, Sullivan received a direct call from astronauts Chris Cassidy, Doug Hurley and Bob Behnken on the International Space Station offering their congratulations on her achievement.