scope:

Purpose

This handbook provides a uniform approach for performing LLA as a living risk assessment document for GSFC missions that is performed concurrently with design efforts and refined as the designs, materials, mission parameters, or processes are refined.

LLA can provide the following project benefits:

• Verification of NASA limited-life requirement and Goddard Open Learning Design (GOLD) Rule compliance

• Identification of candidates for Critical Items List

• Risk identification

• Identification of items requiring maintenance or refurbishment

• Input to sparing plans

• Input to test plans

Proper LLA greatly reduces the risk of premature mission failures by ensuring life margin for wear-out or age-limited items. It also enables missions to be extended with some confidence that hardware will not fail due to life-limiting characteristics.

Applicability

The guidance set forth in this document provides the baseline approach for LLA on all missions, spacecraft, instruments, ground systems, systems, subsystems, and components developed by, contracted by, or manufactured by GSFC and/or any subsidiary facility.

This handbook may be cited in contracts, program, project, and other Agency documents to provide technical guidance. This handbook was developed mainly with the intent of improving the reliability of flight systems. It can be tailored to apply to ground systems, e.g., use of Table 2.

Safety

Limited-Life Items (LLI) identified as affecting safety should be reported to the cognizant project safety manager for inclusion in the appropriate safety analysis.