Future Planetary Exploration: Like Goldilocks's bears, NASA's planetary missions come in three sizes. by Van Kane
'At the low end, costing $600-700 million, are the more frequent Discovery missions that address tightly-focused questions on (for planetary exploration) tight budgets. NASA plans to fly several Discovery missions in the coming decade. At the high end, typically costing greater than $2 billion, are the Flagship missions that host a wide range of instruments for in-depth studies. NASA typically flies just one Flagship mission a decade, although the next decade will see two launches, the Mars 2020 rover and the Europa Clipper.
'However, there are a range of studies that the scientific community deems essential to understanding the solar system that can't fit within the Discovery program, but don't require a Flagship mission. This is the role of the New Frontiers program with missions costing somewhere around $1 billion with a planned flight rate of two per decade.
'The list of possible missions for the New Frontiers program are pre-selected by a panel of scientists once a decade in a process that sets exploration priorities known as the Decadal Survey. For this current competition, NASA’s managers added two additional targets, Saturn’s moons Enceladus and Titan.'
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