Human-rating certification
Human-rating certification,also known asman-ratingorcrew-rating,is the certification of aspacecraftorlaunch vehicleas capable of safely transporting humans. There is no one particular standard for human-rating a spacecraft or launch vehicle, and the various entities that launch or plan to launch such spacecraft specify requirements for their particular systems to be human-rated.
NASA
[edit]One entity that applies human rating is theUS governmentcivilian space agency,NASA.NASA's human-rating requires not just that a system be designed to be tolerant of failure and to protect the crew even if an unrecoverable failure occurs, but also that astronauts aboard a human-rated spacecraft have some control over it.[1]This set of technical requirements and the associated certification process for crewed space systems are in addition to the standards and requirements for all of NASA's space flight programs.[1]
The development of theSpace Shuttleand theInternational Space Stationpre-dated later NASA human-rating requirements. After theChallengerandColumbiaaccidents, the criteria used by NASA for human-rating spacecraft were made more stringent.[2]
Commercial Crew Program (CCP)
[edit]The NASA CCP human-rating standards require that theprobabilityof a loss on ascent does not exceed 1 in 500, and that the probability of a loss on descent did not exceed 1 in 500. The overall mission loss risk, which includes vehicle risk frommicrometeoritesandorbital debriswhile in orbit for up to 210 days, is required to be no more than 1 in 270.[3]Maximum sustainedaccelerationis limited to 3g.[3]
TheUnited Launch Alliance(ULA) published a paper submitted toAIAAdetailing the modifications to itsDelta IVandAtlas Vlaunch vehicles that would be needed to conform to NASA Standard 8705.2B.[2]ULA has since been awarded $6.7 million under NASA'sCommercial Crew Development(CCDev) program for development of anEmergency Detection System,one of the final pieces that would be needed to make these launchers suitable for human spaceflight.[4]
SpaceXis usingDragon 2,launched on aFalcon 9 Block 5rocket, to deliver crew to the ISS. Dragon 2 made itsfirst uncrewed test flightin March 2019 and has been conducting crewed flights sinceDemo-2in May 2020.[5]
Boeing'sStarlinerspacecraft is also a part of the Commercial Crew Program sinceBoeing CFTin June 2024.
CMSA
[edit]TheChina Manned Space Agency(CMSA) operates and oversees crewed spaceflight activities launched from China, including theShenzhouspacecraft andTiangong space station.
Roscosmos
[edit]Roscosmos,a Russianstate corporation,conducts and oversees human spaceflights launched from Russia. This includesSoyuzspacecraft and theRussian Orbital Segmentof the International Space Station.
ISRO
[edit]The space agency of India,ISRO,oversees planned human spaceflights launched from India.[6]
On 13 February 2024 theCE-20engine, after a series of ground qualification tests, was certified for crewedGaganyaanspaceflight missions.[7]The CE-20 will power the upper stage of the human-rated version of theLVM3(formerly known as GSLV Mk III) launch vehicle.
Private spaceflight companies
[edit]Eachprivate spaceflightsystem builder typically sets up their own specific criteria to be met before carrying humans on aspace transportsystem.
See also
[edit]References
[edit]- ^ab"Human Rating Requirements for Space Systems".NASA.10 July 2017.
- ^ab"Atlas and Delta Capabilities to Launch Crew to Low Earth Orbit"(PDF).United Launch Alliance. n.d.Retrieved27 November2011.
- ^abChaikin, Andrew (16 November 2011)."Certified Safe: Planning to operate a taxi service for NASA astronauts? Here's what's required".Air and Space Smithsonian.Retrieved27 November2011.
We've separated [the "loss of crew" criteria] into what you need for ascent and what you need for entry. For ascent, it's 1 in 500, and independently for entry, it's 1 in 500... The probability for the mission itself is 1 in 270. That is an overall number. That's the loss of crew for the entire mission profile, including ascent, on-orbit, and entry. The thing that drives the 1 in 270 is really micrometeorites and orbital debris... whatever things that are in space that you can collide with. So that's what drops that number down, because you've got to look at the 210 days, the fact that your heat shield or something might be exposed to whatever that debris is for that period of time. NASA looks at Loss of Vehicle the same as Loss of Crew. If the vehicle is damaged and it may not be detected prior to de-orbit, then you have a loss of crew.
- ^"NASA and ULA confirm Atlas V baseline for human rated launches".NASASpaceflight.19 July 2012.Retrieved24 July2014.
- ^"Live coverage: NASA astronauts launch from U.S. soil for first time in nine years".Spaceflight Now.30 May 2020.
- ^"Suits from Vadodara, parachutes from Agra: Inside ISRO's plan to launch India's first astronauts".The Economic Times.18 January 2019.Retrieved17 May2019.
- ^"Successful completion of Human rating of CE20 Cryogenic engine for the Gaganyaan Programme".isro.gov.in.Retrieved25 February2024.