Human-rating certification
Encyclopedia
Human-rated or man-rated are terms used to describe the certification of a spacecraft
, launch vehicle
or airplane
as worthy of transporting humans. NASA
and the U.S. GAO
now uses "Human-rating" when describing requirements for these systems. The terms "man-rated" and "human-rated" are mostly used interchangeably.
In spaceflight
, a human-rating certification is the assurance that the space system accommodates human needs, effectively utilizes human capabilities, controls hazards with sufficient certainty to be considered safe for human operations, and provides, to the maximum extent practical, the capability to safely recover the crew from hazardous situations. In the United States
, the National Aeronautics and Space Administration (NASA) has published NASA Procedural Requirement 8705.2 - Human Rating Requirements for Space Systems, defining the certification process and a set of technical requirements to be applied to its crewed space systems in addition to the standards and requirements that are mandatory for all of NASA's space flight programs.
(ISS).
The NASA CCP human-rating standards require that the probability
of loss on ascent is no more than 1 in 500, and that the probability of loss on descent is no more than 1 in 500. The overall mission loss risk, which includes vehicle risk from micrometeorites and orbital debris
while in orbit for up to 210 days is no more than 1 in 270. Maximum sustained G-loads
are limited to three ravity of Earth|Earth-standard g's.
It is noteworthy that the development of the Space Shuttle
and the International Space Station
pre-dates the NASA Human-Rating requirements. After the Challenger
and Columbia
accidents, the criteria used by NASA for human-rating spacecraft have been made more stringent.
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.
ULA has since been awarded $6.7 million under NASA's Commercial Crew Development
(CCDev) program for development of an Emergency Detection System
, one of the final pieces that would be needed to make these launchers suitable for manned spaceflight.
Spacecraft
A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....
, launch vehicle
Launch vehicle
In spaceflight, a launch vehicle or carrier rocket is a rocket used to carry a payload from the Earth's surface into outer space. A launch system includes the launch vehicle, the launch pad and other infrastructure....
or airplane
as worthy of transporting humans. NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
and the U.S. GAO
Gao
Gao is a town in eastern Mali on the River Niger lying ESE of Timbuktu. Situated on the left bank of the river at the junction with the Tilemsi valley, it is the capital of the Gao Region and had a population of 86,663 in 2009....
now uses "Human-rating" when describing requirements for these systems. The terms "man-rated" and "human-rated" are mostly used interchangeably.
In spaceflight
Spaceflight
Spaceflight is the act of travelling into or through outer space. Spaceflight can occur with spacecraft which may, or may not, have humans on board. Examples of human spaceflight include the Russian Soyuz program, the U.S. Space shuttle program, as well as the ongoing International Space Station...
, a human-rating certification is the assurance that the space system accommodates human needs, effectively utilizes human capabilities, controls hazards with sufficient certainty to be considered safe for human operations, and provides, to the maximum extent practical, the capability to safely recover the crew from hazardous situations. In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, the National Aeronautics and Space Administration (NASA) has published NASA Procedural Requirement 8705.2 - Human Rating Requirements for Space Systems, defining the certification process and a set of technical requirements to be applied to its crewed space systems in addition to the standards and requirements that are mandatory for all of NASA's space flight programs.
NASA Commercial Crew Program
In November 2011, Greg Mango, the agency head of the NASA Commercial Crew Program (CCP), gave an extended inteview on the new NASA requirements for human rating of spacecraft that will fly to the International Space StationInternational Space Station
The International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...
(ISS).
The NASA CCP human-rating standards require that the probability
Probability
Probability is ordinarily used to describe an attitude of mind towards some proposition of whose truth we arenot certain. The proposition of interest is usually of the form "Will a specific event occur?" The attitude of mind is of the form "How certain are we that the event will occur?" The...
of loss on ascent is no more than 1 in 500, and that the probability of loss on descent is no more than 1 in 500. The overall mission loss risk, which includes vehicle risk from micrometeorites and orbital debris
Space debris
Space debris, also known as orbital debris, space junk, and space waste, is the collection of objects in orbit around Earth that were created by humans but no longer serve any useful purpose. These objects consist of everything from spent rocket stages and defunct satellites to erosion, explosion...
while in orbit for up to 210 days is no more than 1 in 270. Maximum sustained G-loads
G-force
The g-force associated with an object is its acceleration relative to free-fall. This acceleration experienced by an object is due to the vector sum of non-gravitational forces acting on an object free to move. The accelerations that are not produced by gravity are termed proper accelerations, and...
are limited to three ravity of Earth|Earth-standard g's.
It is noteworthy that the development of the Space Shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
and the International Space Station
International Space Station
The International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...
pre-dates the NASA Human-Rating requirements. After the Challenger
Space Shuttle Challenger disaster
The Space Shuttle Challenger disaster occurred on January 28, 1986, when Space Shuttle Challenger broke apart 73 seconds into its flight, leading to the deaths of its seven crew members. The spacecraft disintegrated over the Atlantic Ocean, off the coast of central Florida at 11:38 am EST...
and Columbia
Space Shuttle Columbia
Space Shuttle Columbia was the first spaceworthy Space Shuttle in NASA's orbital fleet. First launched on the STS-1 mission, the first of the Space Shuttle program, it completed 27 missions before being destroyed during re-entry on February 1, 2003 near the end of its 28th, STS-107. All seven crew...
accidents, the criteria used by NASA for human-rating spacecraft have been made more stringent.
The United Launch Alliance
United Launch Alliance
United Launch Alliance is a joint venture of Lockheed Martin and Boeing. ULA was formed in December 2006 by combining the teams at these companies which provide spacecraft launch services to the government of the United States. U.S...
(ULA) published a paper submitted to AIAA detailing the modifications to its Delta IV and Atlas V
Atlas V
Atlas V is an active expendable launch system in the Atlas rocket family. Atlas V was formerly operated by Lockheed Martin, and is now operated by the Lockheed Martin-Boeing joint venture United Launch Alliance...
launch vehicles that would be needed to conform to NASA Standard 8705.2B.
ULA has since been awarded $6.7 million under NASA's Commercial Crew Development
Commercial Crew Development
Commercial Crew Development is a multiphase space technology development program, funded by the U.S. government, and administered by NASA. The program is intended to stimulate development of privately operated crew vehicles to low Earth orbit. It is run by the Commercial Crew and Cargo Program...
(CCDev) program for development of an Emergency Detection System
Emergency Detection System
An Emergency Detection System is a system that is used on manned rocket missions. It monitors critical launch vehicle and spacecraft systems and issues status, warning and abort commands to the crew during their mission to low Earth orbit. It can trigger the Launch Abort System which will take the...
, one of the final pieces that would be needed to make these launchers suitable for manned spaceflight.