Vision and Voyages for Planetary Science in the - Solar System ...

TABLE C.1 Similarities and Differences Between Three Different Approaches to Assessing the
Technical, Cost and Risk Characteristics of Spacecraft Missions
TMC ICE CATE
Used consistently to compare several concepts Yes No Yes
Concept cost is evaluated with respect to Cost Cap Project Budget Budget Wedge
Maturity of concept
Evaluation Process Includes:
Phase A-B Phase B-D Pre-Phase A
Quantified schedule growth cost threat No Typically Yes
Quantified design growth cost threat No No Yes
Cost threat for increase in launch vehicle capability No No Yes
Independent estimates for non-U.S. contributions No No Yes
Reconciliation performed with project team No Yes No
Technical and cost risk rating (low, medium, high) Yes No Yes
ICEs are typically done late in the lifecycle of a project after it has matured. They often do not
consider certain aspects of cost growth associated with design evolution in the earliest phases of a project.
The objective of the CATE process is to perform a cost and technical risk analysis for a set of concepts
that may have a broad range of maturity, and to assure that the analysis is consistent, fair, and informed by
historical data. Typically, concepts evaluated via the CATE process are early in their lifecycle, and
therefore are likely to undergo significant subsequent design changes. Historically, such changes have
resulted in cost growth. Therefore, a robust process is required that fairly treats a concept of low maturity
relative to one that has undergone several iterations and review. CATEs take into account several
components of risk assessment (Table C.1).
Because the CATE is best suited to the comparative evaluation of a family of pre-Phase A
concepts, it is the methodology used in this decadal survey.
OVERVIEW OF THE CATE PROCESS
The NRC engaged the services of the Aerospace Corporation to perform independent CATEs of
mission concepts identified by the committee’s steering group during this study. Aerospace’s CATE team
consisted of technical, cost and schedule experts.
The committee’s five panels identified a total of 24 missions (Appendix G) that could address key
scientific questions within their respective purviews. To ensure that the mission concepts were
sufficiently mature for subsequent evaluation by the CATE team, NASA commissioned technical studies
at leading design centers, including the Jet Propulsion Laboratory, the Goddard Space Flight Center, the
Applied Physics Laboratory, and Marshall Spaceflight Center. The committee’s steering group selected
concepts to be studied from those recommended by the panels. One or more “science champions” drawn
from the ranks of the panels was attached to each of the centers’ study team to ensure that the concepts
remained true to the scientific and measurement objectives of their originating panel.
The design centers conducted two different types of studies: rapid mission architecture (RMA)
studies and full mission studies. The RMAs were conducted for immature but promising concepts for
which a broad array of mission types could be evaluated to choose the one most promising approach. The
resulting “point design” could then be subjected to a full mission study along with more mature concepts.
Not all missions receiving RMA studies were selected by the steering group for full mission studies. Nor
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