Sunita Williams is an American astronaut and United States Navy officer of Indo-Slovenian descent. She formerly held the records for total spacewalks by a woman (seven) and most spacewalk time for a woman (50 hours, 40 minutes).

Williams was assigned to the International Space Station as a member of Expedition 14 and Expedition 15. In 2012, she served as a flight engineer on Expedition 32 and then commander of Expedition 33.

Williams was commissioned an ensign in the United States Navy in May 1987. After a six-month temporary assignment at the Naval Coastal System Command, she was designated a Basic Diving Officer. She next reported to the Naval Air Training Command, where she was designated a Naval Aviator in July 1989. She received initial H-46 Sea Knight training in Helicopter Combat Support Squadron 3 (HC-3), and was then assigned to Helicopter Combat Support Squadron 8 (HS-8) in Norfolk, Virginia, with which she made overseas deployments to the Mediterranean, Red Sea and the Persian Gulf for Operation Desert Shield and Operation Provide Comfort.

In 1993, Williams began training at the U.S. Naval Test Pilot School. She graduated in December, and was assigned to the Rotary Wing Aircraft Test Directorate as an H-46 Project Officer and V-22 chase pilot in the T-2. In December 1995, she went back to the Naval Test Pilot School as an instructor in the Rotary Wing Department and as the school’s Safety Officer. She then went to the USS Saipan as the Aircraft Handler and the Assistant Air Boss. Williams was deployed on the Saipan in June 1998 when she was selected by NASA for the astronaut program.

Williams began her Astronaut Candidate training at the Johnson Space Center in August 1998. It included orientation briefings and tours, numerous scientific and technical briefings, intensive instruction in Space Shuttle and International Space Station systems, physiological training and ground school to prepare for T-38 flight training, as well as learning water and wilderness survival techniques.

Following training and evaluation, Williams worked in Moscow with the Russian Space Agency on the Russian contribution to the ISS, and with the first expedition crew sent to the ISS. After Expedition 1 returned, Williams worked in the Robotics branch on the ISS Robotic Arm and the related Special Purpose Dexterous Manipulator. She was a crew member on the NEEMO 2 mission, and lived underwater in the Aquarius habitat for nine days in May 2002.

In 2008, Williams served as NASA’s Deputy Chief of the Astronaut Office. She was assigned as a backup crew member for Expedition 30 to the International Space Station, is a crew member of Expedition 32, which launched in July 2012, and then became the Commander of Expedition 33, which began in September 2012.

Like many astronauts, Williams is a licensed amateur radio operator, having passed the technician-class license exam in 2001, and was issued the call sign KD5PLB by the Federal Communications Commission on August 13, 2001. She used one of the two amateur radio stations aboard the ISS when she talked with school children. In 2009, Williams appeared on the “The Colbert Report” to announce that “Tranquility” was the winning name for Node 3 of the ISS.

In July 2015, NASA announced Williams as one of the first astronauts for U.S. Commercial spaceflights.[29] Subsequently, she has started working with Boeing and SpaceX to train in their commercial crew vehicles, along with other chosen astronauts. In August 2018 she was assigned to the first mission flight, CTS-1, to the International Space Station of the Boeing CST-100 Starliner.