Science traceability

Any comprehensive science mission proposal must be able to simply explain why it is important to accomplish the goals of the mission and how it will be implemented. This can be accomplished through use of a Science traceability matrix, a construct that is becoming a required component of all NASA science mission proposals. The science traceability matrix (STM) provides the overview of what a Mission will accomplish relative to high-level objectives suggested through Academy of science surveys, NASA roadmaps, or program objectives. It provides a logical flow from these high level objectives through mission objectives, science objectives, measurement objectives, measurement requirements, instrument requirements and spacecraft and system requirements to data products and eventual publications. It is the one document that shows the relationship between all these key elements and the one document that provides the breadth needed to perform and document high level trades effecting science outcome and overall design. The STM can be used as a gauge to determine the completeness of the definition of a proposed mission. If the matrix flows effortlessly from high level objective to publishable science result then it has been carefully laid out. If the logic that ties one aspect to another is not clear then there is more work to be done prior to any proposal preparation. The science matrix provides a basis for negotiating lower level requirements (typically tracked with tools such as Telelogic´s DOORS® requirements tracking tool) and evaluating affects of the results of those negotiations on the ability to achieve objectives originating at higher levels. It also provides a succinct snapshot of those high level objectives particularly important for high-level goals since there is often no objective algorithm to quantify the relative merits of the conflicting high-level goals. For this case, the matrix provides a convenient notation for assessing and arbitrating the impa- ct on equal-valued objects caused by changes in available mission resources.