Sunita Williams is a

The correct answer is: Astronaut.

Sunita Williams is an American astronaut and engineer in the United States Navy. She is the first Indian-American woman in space. She has logged over 322 days in space on four Space Shuttle missions.

An astrophysicist is a scientist who studies the physical properties of stars, planets, and other celestial objects. A missile scientist is a scientist who studies the design, development, and testing of missiles. A nuclear scientist is a scientist who studies the properties of the atom and its nucleus.

Astronauts are people who travel into space. They are trained to operate spacecraft and conduct scientific experiments in space.