Nash leads the A-Team (the A stands for “architecture”), which can bring a space mission from a mere notion to a detailed study with sharply defined science objectives and a plan for how to achieve them.

In terms of Nash’s Venn diagram, the A-Team endeavors to sketch out a mission that sits in the middle: one that will give scientists the data they want, be something that engineers can build, and merit NASA’s approval to buy and fly.

Periodically, the team checks to see whether the spacecraft design “closes”—whether the myriad parts of the system work with each other to form an internally consistent whole that achieves its objectives given the space provided and for the correct price.

Missions in the billion-­dollar New Frontiers class are rarer still, and their destinations tend to be tied to a short list identified in the Decadal Survey, a community report written by planetary scientists that is released every 10 years.

The most recent SIMPLEx announcement of opportunity limits small sats for non-Earth missions to dimensions that would fit on a specific payload adapter—about the size of a dorm-room fridge and a weight of 400 pounds.

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