Spacecraft call signs are radio call signs used for communication in crewed spaceflight. These are not formalized or regulated to the same degree as other equivalent forms of transportation, like aircraft. The three nations currently launching crewed space missions use different methods to identify the ground and space radio stations; the United States uses either the names given to the space vehicles or else the project name and mission number. Russia traditionally assigns code names as call signs to individual cosmonauts, more in the manner of aviator call signs, rather than to the spacecraft.
The Boeing Starliner is a spacecraft designed to transport crew to and from the International Space Station (ISS) and other low-Earth-orbit destinations. Developed by Boeing under NASA's Commercial Crew Program (CCP), it consists of a reusable crew capsule and an expendable service module.
Development of the Commercial Crew Program (CCDev) began in the second round of the program, which was rescoped from a smaller technology development program for human spaceflight to a competitive development program that would produce the spacecraft to be used to provide crew transportation services to and from the International Space Station (ISS). To implement the program, NASA awarded a series of competitive fixed-price contracts to private vendors starting in 2011. Operational contracts to fly astronauts were awarded in September 2014 to SpaceX and Boeing, and NASA expected each company to complete development and achieve crew rating in 2017. Each company performed an uncrewed orbital test flight in 2019.
The retirement of NASA's Space Shuttle fleet took place from March to July 2011. Discovery was the first of the three active Space Shuttles to be retired, completing its final mission on March 9, 2011; Endeavour did so on June 1. The final shuttle mission was completed with the landing of Atlantis on July 21, 2011, closing the 30-year Space Shuttle program.
Dragon 2 is a class of partially reusable spacecraft developed, manufactured, and operated by American space company SpaceX for flights to the International Space Station (ISS) and private spaceflight missions. The spacecraft, which consists of a reusable space capsule and an expendable trunk module, has two variants: the 4-person Crew Dragon and Cargo Dragon, a replacement for the Dragon 1 cargo capsule. The spacecraft launches atop a Falcon 9 Block 5 rocket, and the capsule returns to Earth through splashdown.
Crew Dragon Demo-1 was the first orbital test of the Dragon 2 spacecraft. The mission launched on 2 March 2019 at 07:49:03 UTC, and arrived at the International Space Station on 3 March 2019, a little over 24 hours after the launch. The mission ended with a splashdown on 8 March 2019 at 13:45:08 UTC.
Crew Dragon Demo-2 was the first crewed test flight of the Crew Dragon spacecraft. The spacecraft, named Endeavour, launched on 30 May 2020 on a Falcon 9 rocket, and carried NASA astronauts Doug Hurley and Bob Behnken to the International Space Station in the first crewed orbital spaceflight launched from the United States since the final Space Shuttle mission in 2011, and the first ever operated by a commercial provider. Demo-2 was also the first two-person orbital spaceflight launched from the United States since STS-4 in 1982. Demo-2 completed the validation of crewed spaceflight operations using SpaceX hardware and received human-rating certification for the spacecraft, including astronaut testing of Crew Dragon capabilities on orbit.
The Boeing Starliner Orbital Flight Test was the first orbital mission of the CST-100 Starliner spacecraft, conducted by Boeing as part of NASA's Commercial Crew Program. The mission was planned to be an eight-day test flight of the spacecraft, involving a rendezvous and docking with the International Space Station (ISS), and a landing in the western United States. The mission was launched on December 20, 2019 at 11:36:43 UTC or 06:36:43 AM EST; however an issue with the spacecraft's Mission Elapsed Time (MET) clock occurred 31 minutes into flight. This anomaly caused the spacecraft to burn into an incorrect orbit, preventing a rendezvous with the International Space Station (ISS). The mission was reduced to just two days, with the spacecraft successfully landing at White Sands Space Harbor on December 22, 2019.
Boeing Crew Flight Test (Boe-CFT) was the first crewed mission of the Boeing Starliner capsule. Launched on 5 June 2024, the mission flew a crew of two NASA astronauts, Barry E. Wilmore and Sunita Williams, from Cape Canaveral Space Force Station to the International Space Station. The mission was meant to last eight days, ending on 14 June with a landing in the American Southwest. However, Starliner's thrusters malfunctioned as it approached the ISS. After more than two months of investigation, NASA decided it was too risky to return Wilmore and Williams to Earth aboard Starliner. Instead, the Boeing spacecraft returned uncrewed on 7 September 2024, and the astronauts will ride down on the SpaceX Crew-9 spacecraft in February 2025.
SpaceX Crew-1 was the first operational crewed flight of a Crew Dragon spacecraft, and the maiden flight of the Crew Dragon Resilience spacecraft. It was also the second crewed orbital flight launch by the United States since that of STS-135 in July 2011. Resilience launched on 16 November 2020 at 00:27:17 UTC on a Falcon 9 from Kennedy Space Center Launch Complex 39A (LC-39A), carrying NASA astronauts Michael Hopkins, Victor Glover and Shannon Walker, along with JAXA astronaut Soichi Noguchi, all members of the Expedition 64 crew. The mission was the second overall crewed orbital flight of the Crew Dragon.
The Boeing Orbital Flight Test-2 was a repeat of Boeing's unsuccessful first Orbital Flight Test (Boe-OFT) of its Starliner spacecraft. The uncrewed mission was part of NASA's Commercial Crew Program. OFT-2, using Starliner Spacecraft 2, launched 19 May 2022 and lasted 6 days. Starliner successfully docked with the International Space Station (ISS) on 21 May 2022. It stayed at the ISS for 4 days before undocking and landing in the White Sands Missile Range on 25 May 2022.
Boeing Starliner Calypso is a space capsule manufactured by Boeing and used in NASA's Commercial Crew Program. On 20 December 2019, Calypso launched on the Boeing Orbital Flight Test mission, an uncrewed test flight of Starliner to the International Space Station. The spacecraft was scheduled to dock to the ISS and then return to Earth following a week in space, although due to several software issues the spacecraft was unable to rendezvous with the station and landed after two days in space, resulting in Boeing needing to schedule a second Orbital Flight Test. It flew with two astronauts for Starliner Crewed Flight Test on its second mission in June 2024.
Axiom Mission 1 was a privately funded and operated crewed mission to the International Space Station (ISS). The mission was operated by Axiom Space out of Axiom's Mission Control Center MCC-A in Houston, Texas. The flight launched on 8 April 2022 from Kennedy Space Center in Florida. The spacecraft used was a SpaceX Crew Dragon. The crew consisted of Michael López-Alegría, a Spaniard-American and a professionally trained astronaut hired by Axiom, Eytan Stibbe from Israel, Larry Connor from the United States, and Mark Pathy from Canada.
The Commercial Crew Program (CCP) provides commercially operated crew transportation service to and from the International Space Station (ISS) under contract to NASA, conducting crew rotations between the expeditions of the International Space Station program. American space manufacturer SpaceX began providing service in 2020, using the Crew Dragon spacecraft, and NASA plans to add Boeing when its Boeing Starliner spacecraft becomes operational no earlier than 2025. NASA has contracted for six operational missions from Boeing and fourteen from SpaceX, ensuring sufficient support for ISS through 2030.
Crew Dragon Endeavour is the first operational Crew Dragon reusable spacecraft manufactured and operated by SpaceX. The spacecraft is named after Space ShuttleEndeavour. It first launched on 30 May 2020 to the International Space Station (ISS) on the Crew Dragon Demo-2 mission. It has subsequently been used for the SpaceX Crew-2 mission that launched in April 2021, the private Axiom Mission 1 that launched in April 2022, the SpaceX Crew-6 mission that launched in March 2023, and the SpaceX Crew-8 mission from early March 2024 to late October 2024. As of November 2024, Endeavour holds the single-mission record for the most time in orbit by an American crewed spacecraft at 235 days.
SpaceX Crew-2 was the second operational flight of a Crew Dragon spacecraft, and the third overall crewed orbital flight of the Commercial Crew Program. The mission was launched on 23 April 2021 at 09:49:02 UTC, and docked to the International Space Station on 24 April at 09:08 UTC.
SpaceX Crew-4 was the Crew Dragon's fourth NASA Commercial Crew operational flight, and its seventh overall crewed orbital flight. The mission launched on 27 April 2022 at 07:52 UTC before docking with the International Space Station (ISS) at 23:37 UTC. It followed shortly after the private Axiom 1 mission to the ISS earlier in the month utilizing SpaceX hardware. Three American (NASA) astronauts and one European (ESA) astronaut were on board the mission.
SpaceX Crew-5 was the fifth operational NASA Commercial Crew Program flight of a Crew Dragon spacecraft, and the eighth overall crewed orbital flight. The mission was successfully launched on 5 October 2022 with the aim of transporting four crew members to the International Space Station (ISS). The Crew Dragon spacecraft docked at the ISS on 6 October 2022 at 21:01 UTC.
Crew Dragon Freedom is the fourth operational Crew Dragon reusable spacecraft manufactured and operated by SpaceX. It first launched on 27 April 2022 to the International Space Station (ISS) on the SpaceX Crew-4 mission. It was subsequently used for two private spaceflight missions to the ISS operated by Axiom Space, Axiom Mission 2 in May 2023 and Axiom Mission 3 in January 2024. It most recently launched to space in September 2024 on the SpaceX Crew-9 mission. The capsule was named after the fundamental human right of freedom and the Freedom 7 capsule that took astronaut Alan Shepard on the first human spaceflight from the United States.
SpaceX Crew-9 is the ninth operational NASA Commercial Crew Program flight and the 15th crewed orbital flight of a Crew Dragon spacecraft. Originally scheduled to launch a crew of four to the International Space Station (ISS) in mid-August 2024, the mission was delayed by more than a month due to technical issues with the Boeing Starliner Calypso spacecraft that was docked at the ISS for the Boeing Crew Flight Test. NASA ultimately decided to send the Starliner back to Earth uncrewed, launch Crew-9 with two crew members, and return with four crew members, including the two crew members of the Boeing Crew Flight Test. After that delay and other delays largely due to weather, Crew-9 launched on 28 September at 17:17:21 UTC.
Crew-8 astronauts at the O&C Building
Crew Dragon Endeavour lifts off from LC-39A
Crew Dragon Endeavour approaching the International Space Station
A SpaceX technician secures a strap around Crew Dragon Endeavour shortly after it splashed down in the Gulf of Mexico
SpaceX Crew-8 astronauts inside Crew Dragon Endeavour shortly after splashdown and being lifted aboard MV Megan
