What Is the Decadal Survey?

The planetary science decadal survey or, simply, "the planetary decadal," is a report prepared by the National Academy of Sciences, Engineering, and Medicine at the request of NASA every 10 years. The National Academies convenes a committee of leading planetary scientists to write the report, which reflects their consensus opinion of the most important scientific questions facing the community and a priority list of missions to answer them.

The current decadal survey is Origins, Worlds, and Life: A Decadal Strategy for Planetary Science and Astrobiology 2023-2032. It was released in April of 2022.

The decadal provides a framework for all debates about funding priorities in NASA, the White House, and Congress. It serves as both "sword and shield": a means to rally the community around new projects and investigations, and also to defend current priorities against budget cuts.

Lawmakers and NASA take the decadal survey seriously, but they are not bound to it. Budgetary limitations or other political priorities inevitably derail many of its lower-priority recommendations, though historically NASA and Congress have supported its top mission priorities

Writing the decadal survey requires significant effort over the course of nearly two years.  Dozens of scientists serve on its steering committee, and nearly a hundred more provide input via specific topic panels and formal paper submissions.

The Planetary Society submitted two white papers to the process, The Search for Life as a Guidepost to Scientific Revolution, and Increasing the Scope of Planetary Defense Activities: Programs, Strategies, and Relevance in a Post-COVID-19 World. The Planetary Society’s President, Dr. Bethany Ehlmann of Caltech, served on the report’s steering committee.

Recommendations of the Current Decadal Survey, 2023 - 2032

The best way to understand the recommendations in the Decadal Survey is to read the high-level summary in the report. There are many different types of recommendations, and it’s good to get a sense of the complexities.

Briefly, though, the current decadal recommends a balanced program of solar system exploration. No one program or destination should grow too large at the cost of others.

Its top recommendation is that NASA complete the Mars Sample Return campaign.

For flagships, a Uranus orbiter and probe is the top priority, followed by an Enceladus life-detection mission.

Additional recommendations are summarized below. The report proposed an ambitious "recommended" program and a more cost-conscious "level" program:

Recommended ProgramLevel Program
Continue Mars Sample ReturnContinue Mars Sample Return
Five new Discovery selections at the new $800M cost capFive new Discovery selections at the new $800M cost cap
Support Lunar Development and Exploration Program with mid-decade start of Endurance-ASupport Lunar Development and Exploration Program with mid-decade start of Endurance-A
Research & Analysis increased by $1.25 billion over 10 yearsResearch & Analysis increased by $730 million
Continue Planetary Defense Program with NEO Surveyor and a follow-on NEO characterization missionContinue Planetary Defense Program with NEO Surveyor and a follow-on NEO characterization mission
Gradually restore Mars Exploration Program budget with late decade start of Mars Life ExplorerGradually restore Mars Exploration Program budget in late decade with no new start for Mars Life Explorer
3 mid-size New Frontiers missions1 - 2 mid-size New Frontiers missions
Begin Uranus Orbiter and Probe in 2024Begin Uranus Orbiter and Probe in 2028
Begin Enceladus Orbilander in 2029No new start for Enceladus Orbilander this decade
Estimated cost: $41.1 billion over 10 yearsEstimated cost: $35 billion over 10 years