NASA Risk Classification
The NASA risk classification system is meant to guide space mission development from formulation through completion of implementation. It is also meant to be the basis on which program and project managers develop and implement appropriate mission assurance and risk management strategies for the mission.
NASA establishes criteria for each NASA-sponsored payload. Four risk classification levels (A thru D) are defined in the NASA Procedural Requirements (NPR). For example:
Class A: Failure would have extreme consequences to public safety or high priority national science objectives. In some cases, the extreme complexity and magnitude of development will result in a system launching with many low to medium risks based on problems and anomalies that could not be completely resolved under cost and schedule constraints.
All practical measures are taken to achieve minimum risk to mission success. The highest assurance standards are used.
Example Missions: Hubble Space Telescope (HST), James Webb Space Telescope (JWST), Cassini
Class B: Represents a high priority National asset whose loss would constitute a high impact to public safety or national science objectives.
Stringent assurance standards with only minor compromises in application to maintain a low risk to mission success.
Example Missions: Psyche, Mars Science Laboratory (MSL), Mars Exploration Rovers (MER), Mars Atmosphere and Volatile Evolution Mission (MAVEN), OSIRIS-REx
Class C: Represents an instrument or spacecraft whose loss would result in a loss or delay of some key national science objectives.
Medium risk of not achieving mission success may be acceptable. Reduced assurance standards are permitted.
Example Missions: Lunar Reconnaissance Orbiter (LRO),Magnetospheric Multiscale Mission (MMS), Transiting Exoplanet Survey Satellite (TESS), Ionospheric Connection Explorer (ICON)
Class D: Technical risk is medium by design (may be dominated by yellow risks). Many credible mission failure mechanisms may exist. A failure to meet Level 1 requirements prior to minimum lifetime would be treated as a mishap.
Medium or significant risk of not achieving mission success is permitted. Minimal assurance standards are permitted.
Example Missions: Lunar Atmosphere and Dust Environment Explorer (LADEE), Interface Region Imaging Spectrograph (IRIS), Neutron star Interior Composition Explorer (NICER), Deep Space Climate Observatory (DSCOVR)
Interested in learning more about NASA’s Psyche Mission?
The NASA Psyche Mission Innovation Toolkit includes a series of free online courses based on the real-world challenges and skills associated with the Psyche mission’s science, engineering, technology, and teamwork. Click below to learn more: