all crew members, totaling 14 astronauts. The accidents led to national level inquiries and detailed analysis of why the accidents occurred. There was a significant pause where changes were made before the Shuttles returned to flight. The Columbia disaster occurred in 2003, but STS took more than a year off before returning to flight in June 2005 with the STS-114 mission. The previously mentioned break was between January 1986 (when the Challenger disaster occurred) and 32 months later when STS-26 was launched on September 29, 1988. The longest Shuttle mission was STS-80 lasting 17 days, 15 hours. The final flight of the Space Shuttle program was STS-135 on July 8, 2011. Since the Shuttle's retirement in 2011, many of its original duties are performed by an assortment of government and private vessels. The European ATV Automated Transfer Vehicle supplied the ISS between 2008 and 2015. Classified military missions are being flown by the US Air Force's uncrewed spaceplane, the X-37B. By 2012, cargo to the International Space Station was already being delivered commercially under NASA's Commercial Resupply Services by SpaceX's partially reusable Dragon spacecraft, followed by Orbital Sciences' Cygnus spacecraft in late 2013. Crew service to the ISS is currently provided by the Russian Soyuz and, since 2020, the SpaceX Dragon 2 crew capsule, launched on the company's reusable Falcon 9 rocket as part of NASA's Commercial Crew Development program. Boeing is also developing its Starliner capsule for ISS crew service, but has been delayed since its Dec. 2019 uncrewed test flight was unsuccessful. For missions beyond low Earth orbit, NASA is building the Space Launch System and the Orion spacecraft, part of the Artemis program. Accomplishments Space Shuttle missions have included: Spacelab missions Including: Science Astronomy Crystal growth Space physics Construction of the International Space Station (ISS) Crew rotation and servicing of Mir and the International Space Station (ISS) Servicing missions, such as to repair the Hubble Space Telescope (HST) and orbiting satellites Human experiments in low Earth orbit (LEO) Carried to low Earth orbit (LEO): The Hubble Space Telescope (HST) Components of the International Space Station (ISS) Supplies in Spacehab modules or Multi-Purpose Logistics Modules The Long Duration Exposure Facility The Upper Atmosphere Research Satellite The Compton Gamma Ray Observatory The Earth Radiation Budget Satellite The Mir Shuttle Docking Node Carried satellites with a booster, such as the Payload Assist Module (PAM-D) or the Inertial Upper Stage (IUS),