So, here it is finally! The day planetary science nerds like yours truly have been waiting for so long occurred on the 19th of April. On that day, the US National Academy of Science published the Planetary Decadal Survey. This document provides recommendations on where NASA (and the US Congress which ultimately funds it) should focus its efforts on space exploration within our solar system in the coming decade.
While it is not legally binding, the decadal survey carries a lot of weight; for example, NASA went ahead with the two flagship missions that were ranked as the highest priority in the previous decadal survey (Mars Sample return mission - #1 and Europa Clipper - #2). Similar Decadal Surveys cover astronomy and astrophysics (published in 2020), earth science (2017), and heliophysics (planned for 2024).
So, what can we learn from this 782-page document titled ‘Origins, Worlds, and Life: A Decadal Strategy for Planetary Science and Astrobiology 2023-2032’? Pretty much everything you need to know about the state of planetary science in general. As such, it is a great document for anyone wanting to learn more about our solar system, the missions that crisscross it, and the space policy framework that supports them. Nevertheless, there’s a lot to read, so let me highlight some key points here.
For a start, this new decadal survey has Astrobiology in its title (the previous one was called Vision and Voyages). That says a lot about the progress made by this multi-disciplinary field throughout the years and the growing confidence the planetary science community has in their ability to potentially find life elsewhere in our solar system; proposed missions that have names such as Life Explorer (for Mars) or Life Potential (for Venus) are a thing. If there’s life out there, we’re gonna find it in the coming decades.
Secondly, the survey has recommended the highest priority new Flagship mission for the decade 2023-2032 to be the Uranus Orbiter and Probe (OUP) coming in at an estimated cost of $4.1B (expected for a flagship mission). A mission to the ‘ice giants’ is long overdue (was #3 in the previous decadal survey) and the planetary science community on Twitter was buzzing from this announcement. If approved, OUP would launch on a Falcon Heavy with a launch window in 2031-2038 for a cruise time of ~ 15 years and 6 years of mission time; expect a few decades of butt jokes. The second highest priority flagship mission is the Enceladus Orbilander (was #4 in the previous decadal survey), a spacecraft that would orbit the tiny but potentially life-bearing moon of Saturn before studying its surface in situ.
However, it is worth pointing out here that the survey also recommends that ‘The highest scientific priority of NASA’s robotic exploration efforts this decade should be the completion of Mars Sample Return as soon as is practicably possible with no increase or decrease in its current scope’ and that ‘Mars Sample Return (MSR) is of fundamental strategic importance to NASA, U.S. leadership in planetary science, and international cooperation and should be completed as rapidly as possible.’ In other words, if purses are tightened and push comes to shove, the execution of MSR trumps the implementation of OUP. Given the complexity and ballooning costs of MSR, the risk that OUP is not selected by NASA or funded by Congress is real.
Talking about costs, the survey also recommends significant increases (20-40%) in NASA’s Discovery and New Frontiers class missions to account for the outer solar system missions and long life-cycle costs. Whether Congress will follow suit remains to be seen. There’s a lot more in the document that is worth sharing such as how 33 robotic missions were selected and evaluated, the small and medium-size mission recommendations, or the current understanding of numerous planetary bodies. I will come back to this in a future monthly post so watch this space.
In the meantime, you can find the decadal survey on the National Academies website. It makes for a great bedside table read.