Robert "Bob" Thomas Hines, Jr. is an American fighter pilot and NASA astronaut of the class of 2017.

Kathryn Patricia "Kay" Hire is a NASA astronaut and Captain in the U.S. Navy Reserve who has flown aboard two Space Shuttle missions. Hire began work at the Kennedy Space Center in May 1989,first as an Orbiter Processing Facility 3 Activation Engineer selected by NASA in December 1994.

Charles Owen "Scorch" Hobaugh is a former NASA astronaut and a retired U.S. Marine Corps officer. He has had three spaceflights, all of which were Space Shuttle missions to the International Space Station, lasting between 10 and 13 days.

Warren Woodrow "Woody" Hoburg is an American engineer and NASA astronaut of the class of 2017.

Jeffrey Alan Hoffman is an American former NASA astronaut and currently a professor of aeronautics and astronautics at MIT. Hoffman made five flights as a space shuttle astronaut, including the first mission to repair the Hubble Space Telescope in 1993, when the orbiting telescope's flawed optical system was corrected.

Donald Lee Holmquest (born April 7, 1939) is an American lawyer, as well as a physician, electrical engineer and former NASA astronaut. Holmquest was selected as a scientist-astronaut by NASA in August 1967. From May 1971 to September 1973, he completed training in nuclear medicine at Baylor while on two leaves from NASA. When it became clear that he would not be assigned to any Skylab mission after Skylab B was scrapped, he formally resigned from the Astronaut Corps in September 1973.

Scott Jay "Doc" Horowitz is a retired American astronaut and a veteran of four space shuttle missions. Horowitz was selected as an astronaut candidate by NASA in 1992, and piloted missions STS-75 (1996), STS-82 (1997) and STS-101 (2000). He commanded mission STS-105 (2001), a visit to the International Space Station for equipment and crew transfer.

Akihiko Hoshide is a Japanese engineer and JAXA astronaut. On August 30, 2012, Hoshide became the third Japanese astronaut to walk in space. His space selfies from 2012, including another space selfie that was posted on Instagram, appeared at the top of many selfie lists of 2013.

Rick Douglas Husband (July 12, 1957 – February 1, 2003) (Colonel, USAF) was an American astronaut and fighter pilot. He traveled into space twice: as Pilot of STS-96 and Commander of STS-107. He and the rest of the crew of STS-107 were killed when Columbia disintegrated during reentry into the Earth's atmosphere.

Aleksandr Sergeyevich Ivanchenkov (Russian: Алекса́ндр Серге́евич Иванче́нков; born 28 September 1940 ) is a retired Soviet cosmonaut who flew as Flight Engineer on Soyuz 29 and Soyuz T-6, he spent 147 days, 12 hours and 37 minutes in space.

Anatoli Alekseyevich Ivanishin (Russian: Анатолий Алексеевич Иванишин; born 15 January 1969 in Irkutsk) is a Russian cosmonaut. His first visit to space was to the International Space Station on board the Soyuz TMA-22 spacecraft as an Expedition 29 / Expedition 30 crew member, launching in November 2011 and returning in April 2012. Ivanishin was the Commander of the International Space Station for Expedition 49. His third and last spaceflight was as a flight engineer during Expedition 62 / Expedition 63 in 2020. Ivanishin retired in October 2021 to focus on science career.

Major general Georgi Ivanov Kakalov (Bulgarian: Георги Иванов Какалов; born July 2, 1940) is a Bulgarian former military officer who was the first Bulgarian cosmonaut. Ivanov, along with Soviet cosmonaut Nikolai Rukavishnikov, was launched into space as part of the Soyuz 33 mission from Baikonur Cosmodrome on April 10, 1979, at 17:34 (GMT). The scientific program for the flight was prepared entirely by Bulgarian scientists, along with some of the equipment. Though take-off was smooth, the mission was a disaster, with severe damage of the engine preventing docking in orbit to Salyut 6 orbital station as it was initially planned. A premature return to Earth became the only possible decision for Ivanov and Rukavishnikov. Due to some additional technical problems landing was difficult to endure-more than 9Gs. When Soyuz 33 finally landed, it was 320 kilometres (200 mi) southeast of Dzhezkazgan. It completed 31 orbits, and was in space for 1 day, 23 hours, and 1 minute. The flight remains the only example for manual landing and is thus quoted in every astronautic textbook.