Michael Scott Hopkins (born December 28, 1968) is a Colonel in the U.S. Air Force, and a current NASA astronaut. Hopkins was selected in June 2009 as a member of the NASA Astronaut Group 20. He made his first spaceflight as a Flight Engineer on Soyuz TMA-10M/Expedition 37/Expedition 38, from September 2013 until March 2014. He was the first member of his astronaut class to fly in space. As well as being the first member of his class to fly in space, he is set to become the first member of his class to return to space in 2019 as Commander of the first operational SpaceX Crew Dragon mission to the International Space Station.

Douglas Gerald Hurley is an engineer and retired NASA astronaut. He piloted Space Shuttle mission STS-127, which launched July 15, 2009. He was assigned and flew as pilot for STS-135, the final flight of the Space Shuttle program, in July 2011. He is also the first Marine to fly the F/A-18 E/F Super Hornet. His call sign is "Chunky" and was sometimes referred to by this name on the communication loops.

Christopher J. Ferguson is a Boeing commercial astronaut and a retired United States Navy Captain and NASA astronaut. He was the pilot of Space Shuttle Atlantis on his first mission to space, STS-115, which launched on September 9, 2006 and returned to Earth on September 21, 2006. He then commanded STS-126 aboard Space Shuttle Endeavour. In 2011, he was assigned as commander of STS-135, which was the final mission of the space shuttle program. On December 9, 2011, he retired from NASA and is now currently director of Crew and Mission Operations for Boeing's Commercial Crew Program. In August 2018, Ferguson was assigned to the first test flight of the Boeing CST-100 Starliner.

Oleg Germanovich Artemyev (Russian: Олег Германович Артемьев) is a Russian Cosmonaut for the Russian Federal Space Agency. He was selected as part of the RKKE-15 Cosmonaut group in 2003. He was a Flight engineer of Expedition 39 and 40 to the International Space Station, and in 2018 he returned to space as the Commander of Soyuz MS-08.

Andrew Jay "Drew" Feustel is a geophysicist and a NASA astronaut. Following several years working as a geophysicist, Feustel was selected as an astronaut candidate by NASA in July 2000. His first spaceflight in May 2009, STS-125, lasted just under 13 days. This was a mission with six other astronauts to repair the Hubble Space Telescope, aboard Space Shuttle Atlantis. Feustel performed three spacewalks during the mission. His second spaceflight was STS-134, which launched on May 16, 2011 and landed on June 1, 2011. STS-134 was the penultimate Space Shuttle flight. Feustel returned to space on March 21, 2018 on Soyuz MS-08 with Expedition 55/56. For expedition 56, he commanded the International Space Station, before handing over to Alexander Gerst on October 3, 2018.

Richard Robert "Ricky" Arnold II is an American educator and a NASA astronaut. He flew on Space Shuttle mission STS-119, which launched March 15, 2009 and delivered the final set of solar arrays to the International Space Station. He launched again in 2018 to the ISS, onboard Soyuz MS-08.

Serena Maria Auñón-Chancellor is an American physician, engineer, and NASA astronaut. She has been in space since June 6, 2018, serving as a flight engineer in Expedition 56/57 to the International Space Station.

Rear Admiral Alan Bartlett Shepard Jr. was an American astronaut, naval aviator, test pilot, and businessman. In 1961 he became the first American to travel into space, and in 1971 he walked on the Moon.

Donald Kent "Deke" Slayton, was an American World War II pilot, aeronautical engineer, and test pilot who was selected as one of the original NASA Mercury Seven astronauts, and became NASA's first Chief of the Astronaut Office.

Malcolm Scott Carpenter, was an American naval officer and aviator, test pilot, aeronautical engineer, astronaut, and aquanaut. He was one of the original seven astronauts selected for NASA's Project Mercury in April 1959. Carpenter was the second American (after John Glenn) to orbit the Earth and the fourth American in space, following Alan Shepard, Gus Grissom, and Glenn.

Leroy Gordon "Gordo" Cooper Jr. was an American aerospace engineer, test pilot, United States Air Force pilot, and the youngest of the seven original astronauts in Project Mercury, the first manned space program of the United States. Cooper piloted the longest and final Mercury spaceflight in 1963. He was the first American to sleep in space during that 34-hour mission and was the last American to be launched alone to conduct an entirely solo orbital mission. In 1965, Cooper flew as Command Pilot of Gemini 5.

Colonel John Herschel Glenn Jr. was a United States Marine Corps aviator, engineer, astronaut, businessman, and politician. He was the first American to orbit the Earth, circling it three times in 1962. Following his retirement from NASA, he served from 1974 to 1999 as a Democratic United States Senator from Ohio.