Sunday, November 1, 2009

First Decadal Mission Assessments

A major criticism of both the last astronomy and the last planetary Decadal Surveys was that they prioritized ill-defined mission concepts whose true cost was severely under estimated.  As a result, both fields have had embarrassingly large cost overruns on key projects -- the James Webb Space Telescope and the Mars Science Laboratory -- that prevented other high priority missions from being started such as an Europa orbiter.

This time, the planetary Decadal Survey has a major focus on defining and costing missions.  The approach is to do "Rapid Mission Architecture" studies on a large number of missions to get an idea of the engineering requirements and technical readiness.  Then a smaller set of missions judged to be high priority will get full mission studies that are intended to flesh out the details of implementation.  Then a small number of missions will receive detailed cost estimates.  As I understand the process, to be proposed as a priority mission, a mission has to make it through all three stages, and not all missions that get through the costing stage will make the shorter list of recommended missions.  Only a minority of proposed missions will make the cut at each level of assessment and progress to the next stage.

Three organizations -- NASA Goddard, John Hopkin's APL, and NASA's JPL -- will perform the rapid architectures and full mission studies.  Then an outside firm will prepare the cost estimates.

The majority of missions that will enter the process will be proposed by the community itself through the hundreds of White Papers and many panel meetings.  To kick start the process, however, the panels and steering committee selected several missions prior to the delivery of the White Papers.  Early assessment doesn't mean anything in terms of priority.  The goal was to even out the work flow for the organizations involved by getting a head start.

Steve Squyres, chair of the process, listed the first wave of missions in a letter to the community.  You can read the full letter at  The rest of this blog entry quotes the sections that list the first wave of missions to assessed. As an editorial note, I'll point out how wide ranging the types of missions are.  A wide net appears to be being cast to find the intersection of the best science return and the best mission readiness and cost effectiveness.

"Prior to receiving the white papers, each panel met to identify a first set of candidate missions for study. Mission candidate studies were then reviewed and approved by the steering group, and an organization (APL, Goddard, or JPL) was chosen to conduct each study. These studies are just getting underway. IT IS IMPORTANT TO NOTE THAT THESE ARE JUST THE FIRST SET OF MISSION CANDIDATE STUDIES, selected before the white papers were received. There will be many more that have been motivated by the white papers once the white papers have been assessed.

"Six of the studies are of the type known as “Rapid Mission Architecture” studies. These are high-level studies of overall mission architecture that we expect to take a few weeks. The purpose of these studies is to explore the trade space for a mission candidate, and identify a “point design” for possible subsequent study in much greater depth.

"The six Rapid Mission Architecture studies are:
  • Mercury lander mission (APL)
  • Venus near-surface mobile explorer mission (Goddard)
  • Mars 2018 skycrane capabilities study (JPL)
  • Uranus system mission (APL)
  • Neptune/Triton mission (JPL)
  • Enceladus flyby/sample return mission (JPL)
"There are also two full mission studies. These will be more time-consuming and labor-intensive, and are intended to take these mission concepts to the point where they are ready for a full independent cost estimate. The two full mission studies are:
  • Mars trace gas orbiter mission (Goddard)
  • Titan lake mission (JPL)
"There is also one small study to be conducted by JPL that doesn't fit any of the above categories; this study will identify possible targets for Near Earth Object missions.

"In addition to the eight studies listed above, two mission concept studies have been identified that have already been done to a level of maturity such that an independent cost estimate should be possible. Independent cost estimates for each of those will be performed as soon as the company performing the cost estimates is under contract. Those two mission concepts are:
  • Mars trace gas orbiter mission studied to date by JPL
  • Comet surface sample return mission studied to date by APL.
"Note that undergoing an independent cost estimate is a necessary but not sufficient condition for a mission candidate to be included in the final SolarSystem2012 plan. Again, I stress that most of the studies will be commissioned once the white papers have been assessed! "

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