2. Policies, Standards, and Requirements Guidance

NPR 8705.4, Risk Classification for NASA Payloads, establishes baseline criteria that enable a user to define the risk classification level for NASA payloads on human- or nonhuman-rated launch systems or carrier vehicles and the design and test philosophy and the common assurance practices applicable to each level. The establishment of the risk level early in programs and projects provides the basis for program and project managers to develop and implement appropriate mission assurance and risk management strategies and requirements and to effectively communicate the acceptable level of risk.

This directive establishes four risk tolerance classes and the associated objectives corresponding to the acceptable risk and degree of uncertainty that a Mission Directorate assigns to a project. These four distinct risk tolerance classes provide projects with a uniform authoritative source of Agency-level assurance expectations from which managers, Technical Authorities, engineers, etc., can develop, communicate, and implement appropriate mission assurance and risk management strategies and requirements consistent with corresponding NASA assurance standards.

See the R&M Planning with Assurance Case Tab for planning assistance.

The NASA R&M programs are based onNASA-STD-8729.1, NASA Reliability and Maintainability Standard for Spaceflight and Support Systems (current revision is Rev A). The standard provides a comprehensive set of R&M objectives and strategies that spaceflight programs and projects can tailor as needed to ensure R&M is designed and built into their systems. The standard aligns with the objectives-based program- and project-management approach outlined in NPR 7120.5, NASA Space Flight Program and Project Management Requirements. The update now includes an objectives hierarchy, which outlines specific R&M considerations that all NASA projects and programs need to address in their planning, implementation, and evaluation activities.

The standard includes broad technical objectives and strategies that impact reliability, but it is not meant to prescribe specific processes. Rather, the information can be tailored per risk classification and acceptable risk posture as appropriate to incorporate R&M into program and project activities. The standard also lists recommended R&M evidence (including controls, analysis, testing, and inspection) that R&M engineers, and other relevant technical disciplines, can integrate into the planning, execution, and evaluation of a program or project over its life cycle.

For assistance a NASA-STD-8729.1A guidebook has been created on how to use NASA-STD-8729.1A, NASA Reliability and Maintainability (R&M) Standard for Spaceflight and Support Systems. It supplements the information contained within NASA-STD-8729.1A.

See the R&M Planning with Assurance Case Tab for planning assistance.

NPR 8705.2, Human-Rating Requirements for Space Systems, establishes the technical requirement to protect the health and safety of humans involved in or exposed to space activities, specifically the public, crew, passengers, and ground personnel. This policy is implemented through the application of NASA Directives and Standards.

This directive establishes the requirements based on three tenets. These tenets are 1) additional rigor and scrutiny involved in the design, development, certification, and operation of human-rated space systems; 2) providing for the basic human needs such as environment, food, and water, the astronauts onboard the spacecraft must be given some level of control over the system; 3) ensures that system have the capabilities and safeguards that allow for the safe return of the crew after system failures prevent mission continuation.

See the R&M Planning with Assurance Case Tab for planning assistance.