Leroy Chiao is an American chemical engineer, retired NASA astronaut, entrepreneur, motivational speaker, and engineering consultant. Chiao flew on three Space Shuttle flights, and was the commander of Expedition 10, where he lived on board the International Space Station from October 13, 2004 to April 24, 2005. He is also a co-author and researcher for the Advanced Diagnostic Ultrasound in Microgravity project.