After the Challenger and Columbia accidents, the criteria used by NASA for human-rating spacecraft were made more stringent.
[3] Maximum sustained acceleration is limited to 3 g.[3] The United Launch Alliance (ULA) published a paper submitted to AIAA detailing the modifications to its Delta IV and Atlas V launch vehicles that would be needed to conform to NASA Standard 8705.2B.
Roscosmos, a Russian state corporation, conducts and oversees human spaceflights launched from Russia.
[6] On 13 February 2024 the CE-20 engine, after a series of ground qualification tests, was certified for crewed Gaganyaan spaceflight missions.
[7] The CE-20 will power the upper stage of the human-rated version of the LVM3 (formerly known as GSLV Mk III) launch vehicle.