Systems that must operate in a radiation environment have to be designed to be survivable (hard) to radiation stress levels specified for them. In addition to design hardening, a Hardness Assurance (HA) program must also be developed during the system design phase for implementation of the production phase. The HA program consists of the production controls and tests which assure that each end product, i.e., delivered system, meets the hardened design specifications and requirements. This handbook is a revision and combination of the earlier MIL-HDBK-279 (see 6.1) and MIL-HDBK-280 (see 6.2) which in turn were the results of earlier work performed under the auspices of the Defense Nuclear Agency ((DNA see 6.3 and 6.4).