Improving Space Logistics and Supportability Using Self-Prognostic Equipment on Spacecraft

Abstract

To improve logistics and supportability for existing and future space systems, the key design driver needs to be equipment usable life rather than equipment performance. Today, all space system procurement contracts require equipment performance to be measured and confirmed before purchase, but the usable life of the equipment is not required to be measured and confirmed resulting in equipment whose reliability/usable life is dominated by premature failures. Premature failures drive space system logistics and supportability, increasing cost and decreasing serviceability. Design engineers analyze the many combinations of exotic engine and fuels that offer extreme performance getting to space and working in space. Design engineers do not design a system to be more reliable because reliability engineers are employed solely to provide the calculations for reliability in probability terms, which is unrelated to equipment usable life. However, reliability-centered systems, which measure equipment usable life, offer superior system availability, maintainability, reliability and supportability. Many of today’s space programs use the routine maintenance program (RMP) that was developed over 50 years when equipment usable life/reliability was dominated by premature failures. These programs must receive the large funding to pay the extreme cost and suffer from the poor system availability associated with the RMP. Today, using the technology developed by companies that suffer financial losses from producing equipment and products that fail prematurely, the expensive RMP can be replaced by the costsaving, condition-based maintenance (CBM) program that is used on the new Air Force F-35 Joint Strike Fighter. The CBM includes using intelligent-based decision-making equipment that decreased the life cycle cost of the F-35 by 50%. Intelligent equipment relies on real-time equipment analog telemetry to determine the exact day of equipment failure so can be used to provide the exact equipment and goods needed for replacement rather than maintaining and shipping supplies that may not be needed but have been to be shipped because of the predefined resupply schedule in the routine maintenance program. In a CBM reliability paradigm, the equipment determines its own remaining usable life, and automatically notifies support personnel to order the right equipment for the right time. The CBM is ideal for improving the logistics and supportability for today and tomorrow’s space exploration programs that benefit financially from having the right equipment and supplies available. Using probability reliability analysis to quantify equipment reliability and factory dynamic environmental factory acceptance testing to measure and confirm equipment performance results in space systems whose usable life/reliability is dominated by infant mortality failures thus forcing large quantities of extra equipment to be available for redundancy. This paper defines the necessary steps for the NASA, commercial and military space programs to reduce cost by replacing the routine maintenance programs with the condition-based maintenance program that yields 50% cost savings and increases safety, reliability, maintainability and supportability as achieved by the Air Force’s F-35 JSF program.