A few years ago I read about a decision methodology that NASA uses to reduce the number of options/variables for future missions. Essentially, they make decisions that will remove the largest number of options earlier in the process. This means they can take thousands of variables and chop them down to a handful by making just a few decisions rather than judge each on its own merit. What is the name of this decision-making model?

  • $\begingroup$ I don't see any question marks... don't think this is a very clear question (well there isn't one actually), but here is my guess of what you are asking: How do they call the action of reducing the number of options or variable for future missions? Is it related to that? $\endgroup$
    – Matthew
    Commented Aug 18, 2017 at 13:31
  • 1
    $\begingroup$ You are right it wasn't clear, yes they have a specific methodology for making big decisions first that reduces the number of decisions they have to make by eliminating many smaller considerations. $\endgroup$
    – Callum K
    Commented Aug 18, 2017 at 13:33
  • $\begingroup$ I don't know if there's a specific name for this approach, but it's not exclusive to NASA, by far. Any competent person in decision making position (that includes e.g. programmers!) will approach the process that way - simply because it cuts down on time and effort of the process. E,g. building database queries, you should place conditions that leave least number of elements first, as each element that passes a condition must be checked against consecutive conditions; removing most of them ASAP reduces the database load. $\endgroup$
    – SF.
    Commented Aug 21, 2017 at 17:06

1 Answer 1


Generally NASA responds to the decadal surveys put together by the National Academies of Science for each major science branch (i.e., Earth, Planetary, Astrophysics, and Heliophysics). The decadal surveys are constructed by a panel of experts, at the request of NASA, from the respective field and presented as a sort of suggestion for the path the field should take over the next decade. It generally tries to frame the current, big unanswered questions that could be addressed by new/future missions. In those reports, the panels often make suggestions for new missions including size/scale (e.g., MIDEX), goals, and timelines.

There is no law stating that NASA must obey the recommendations of these surveys but there is also no reason to ignore them since they are put together by the very people NASA supports and people supporting NASA. So far as I know, there has never been a decadal survey that was ignored by NASA but there is some "wiggle room" for interpretation. The panels are given a little guidance regarding limitations on (expected) funding and scope of potential future missions but not much else.


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