section_path: History and design/Government
section_name: Government
paragraph_text: Government
  
  The first heavy-lift launch vehicles in the 1960s included the US Saturn IB and the Soviet Proton. Saturn IB was designed to carry the Apollo spacecraft into orbit and had increased engine thrust and a redesigned second stage from its predecessor. Proton was originally designed to be a large intercontinental ballistic missile (ICBM). Russia still operates variants of the Proton as of 2024, although it is expected to be phased out in favor of the Angara A5.
  
  NASA introduced the Space Shuttle as the first partially reusable launch vehicle in 1981. The Space Shuttle carried up to eight crew members in addition to deploying heavy payloads to LEO, including space station modules and Department of Defense payloads. Higher-energy orbits for payloads were reached through the use of a kick stage such as the Inertial Upper Stage.
  
  The United States Air Force (USAF) operated the Titan IV to supplement Space Shuttle launches. This was derived from the Titan family of ICBMs and launch vehicles, with upgrades including solid rocket boosters (SRBs), vehicle lengthening, and an optional third stage. The USAF began the Evolved Expendable Launch Vehicle (EELV) program in 1994 to ensure access to space through contracted launch providers. This led to the development of the Delta IV, with the heavy variant using three first stage cores. United Launch Alliance (ULA) introduced Vulcan Centaur in 2024 as the successor to its Delta IV and Atlas V rockets, with Vulcan featuring a single, wider core and optional SRBs.
  
  China's Long March 5 was introduced in 2016 as the most powerful version of the Long March family. It is notable as a Chinese launch vehicle using non- hypergolic liquid propellants.