Christopher Cassidy

On June 2, 2017, Cassidy was replaced by Patrick G. Forrester as Chief of the Astronaut Office and was returned to normal flight status.

Cassidy was named Chief of the Astronaut Office at NASA in July 2015, succeeding Robert L. Behnken.

Cassidy attended York High School, in York, Maine. He then graduated from the Naval Academy Preparatory School in Newport, Rhode Island, in 1989. He received a Bachelor of Science degree in Mathematics from the United States Naval Academy in 1993 and a Master of Science degree in Ocean Engineering from MIT in 2000. While in the Navy, Cassidy passed BUD/S and became a Navy SEAL. While a SEAL, he served several tours of duty supporting the fight in the War on Terror. His first spaceflight was on Space Shuttle mission STS-127, and his second was as a flight engineer for Expedition 35/36, launched aboard Soyuz TMA-08M. He was in space July 15 to 31, 2009, and March 28 to September 10, 2013. Cassidy has worked as a CAPCOM for both International Space Station and Space Shuttle missions in the past. Cassidy is currently serving aboard the ISS as Commander of Expedition 63.

Cassidy was assigned to the Expedition 35 crew as a flight engineer and flew to the ISS aboard Soyuz TMA-08M (US designation: 34S), which launched on March 28, 2013. On May 11, 2013, Cassidy and Thomas Marshburn performed an unplanned spacewalk to replace a pump controller box suspected to be the source of an ammonia coolant leak.

Cassidy participated in two US spacewalks from the ISS in June/July 2013. On July 16, 2013, he was joined by Luca Parmitano on a spacewalk. The EVA was cut short when Parmitano reported water floating behind his head inside his helmet. During the EVA, Cassidy took his space selfie. That photo became one of the best selfies of 2013 listed by many news sites.

Cassidy is an honor graduate of Basic Underwater Demolition/SEAL training (BUD/S) Class 192. He was awarded the Bronze Star with "V" device and the Presidential Unit Citation for leading a 9-day operation at the Zhawar Kili cave complex – a national priority objective directly on the Afghan/Pakistan border during Operation Enduring Freedom. Cassidy was a guest speaker at the USNA Combat Leadership Seminar (2003 and 2004). He was awarded a second Bronze Star for combat leadership service in 2004 during Operation Enduring Freedom in Afghanistan.

Cassidy and his six fellow crew members lifted off aboard Endeavour from the Kennedy Space Center on 15 July 2009, the seven astronauts docked to the ISS on 17 July, joining the six person Expedition 20 crew, commanded by Russian cosmonaut Gennady Padalka, this marked the first time 13 people had been in space together, a record that has not been surpassed since. On 22 July 2009 Cassidy stepped outside the ISS alongside NASA astronaut David Wolf for his first spacewalk, the two began work replacing batteries on the P6 Truss and continued work on installing the JEM-EF, the EVA was called off after 5 hours and 59 minutes due to excess amounts of Carbon dioxide in Cassidy's suit.

On 31 July 2009 Cassidy returned to the KSC Shuttle Landing Facility, wrapping up his first spaceflight after 15 days in space.

In February 2008 Cassidy was assigned to his first spaceflight as a Mission Specialist on STS-127, a Space Shuttle mission to deliver the Exposed Facility of the Japanese Experiment Module (JEM-EF) to the ISS aboard Space Shuttle Endeavour.

Cassidy was selected as an astronaut candidate by NASA in May 2004. In February 2006 he completed Astronaut Candidate Training, which included scientific and technical briefings, intensive instruction in Space Shuttle and International Space Station systems, physiological training, T-38 Talon flight training, and water and wilderness survival training. Completion of this initial training qualified him for various technical assignments within the Astronaut Office and future flight assignment as a mission specialist.

Christopher John "Chris" Cassidy (born January 4, 1970, in Salem, Massachusetts) is a NASA astronaut and United States Navy SEAL. Chris Cassidy achieved the rank of captain in the U.S. Navy. He was the Chief of the Astronaut Office at NASA from July 2015 until June 2017.

Chris Cassidy is also the 500th person in space. He achieved this by being the designated crew member by the rest of his crew mates, during the STS-127 mission. He is also the second SEAL to fly in space following William Shepherd, a veteran of four prior missions.