NASA Earth Observing System Mission Operations Center development using COTS products

Abstract

The original NASA EOS Terra Spacecraft ground command and control system development started as a custom product but was failing to meet the requirements. Less than six months before launch a replacement system was developed. The new development tested COTS products offering the best potential for a low cost, successful delivery. Some difficulties encountered with using the COTS product were that operations concepts varied considerably from the EOS missions. In this case the EOS Flight Operations Team was well established and had settled on a concept of operations. No single standard exists for space-to-ground communications and the ground interfaces were unique to NASA so new interfaces had to be developed. Another consideration was the mission life cycle of 10-to-12 years COTS (Commercial Off-The-Shelf) product life cycles tend to be much shorter. Our approach involved the operations team and selected COTS products that closely matched the original operations concepts. Requirements were scrubbed to identify those critical to launch and which could be deleted or modified. Multiple builds were made to support mission rehearsal requirements and incorporate critical requirements early to allow the greatest amount of test time. The first build was delivered and installed less than 45 days after the initial contract and the first mission rehearsal was more successful than any previous EOS rehearsal on the original system. A subsequent build 90 days later supported all launch critical requirements and the system was declared launch-ready on time to support the planned launch. COTS products can be used to accelerate development schedules, but tailoring of the product is often unavoidable. If extensive tailoring is required, consideration should be given to a custom development. Upgrades to the COTS products can introduce new problems and must be carefully managed.