Avoiding the impossible: Re-focusing a non-feasible mission 2-hrs into a 3-day engineering session

Concurrent engineering (CE) has demonstrated for over twenty years that it can produce high level mission designs in a short period of time, from months to only a few days. Unfortunately, sometimes these designs - while technically sound - are not feasible due to mass or cost constraints. A major new capability is needed by CE teams that will enable mission designers to re-focus a study, and avoid spending a great deal of time and effort with 15 engineers designing a non-feasible mission. The Jet Propulsion Laboratory's Team X is addressing this problem by developing mass and cost models that produce estimates for the probability of breaching a mass or cost threshold within the first hours of a study. These models are built on statistical relationships based on mass and cost allocations per mission component by mission type, derived from over twenty years of Team X studies and NASA missions. By linking these relationships, insights about total mass or cost can be made early in a study, based on preliminary requirements or the first completed spacecraft subsystem designs; estimates incorporate updated spacecraft subsystem designs as they are completed throughout the study. A methodology, generalized model, verification and example implementation for a cost limit breach are presented.