The last time a decadal survey was conducted by the planetary science community, it was found that Mars was ascendant. Since then, NASA has conducted a series of Mars missions and worked on its most ambitious rover yet, Curiosity. The survey was endorsed by backing a mission to collect samples as the first step to returning those samples to Earth.
Now in the latest planetary science decadal survey, which was published on April 19 by a National Academies committee, it is found that there is an inevitable shift in the facts. While Mars is still at the center of much of present-day planetary science at NASA, the planetary decadal has shared that the future is further out in the solar system, among distant planets and icy moons that could harbor life.
URANUS OVER NEPTUNE, ENCELADUS OVER EUROPA
The section that has gotten the most scrutiny is its recommendations for the next flagship missions NASA should pursue. The leaders have decided that the focus of the following central flagship mission should be two of the solar system’s least-studied planets, Uranus and Neptune.
According to the co-chairs of the steering committee of Southwest Research Institute, Robin Canup, “This is the only class of planet in the solar system that hasn’t had a dedicated orbital tour, Understanding the composition and the properties of either one would revolutionise our understanding of ice giant systems and solar system origins.”
She further states that “This may, we think, be the most common class of planet in the universe. For the Uranus Orbiter and Probe, we have a viable end-to-end mission concept right now on currently available launch vehicles.” These planets are called “ice giants” by scientists, as they’re smaller than the gas giant worlds of Jupiter and Saturn and may have some mix of rock and ice in their interiors.
MARS AFTER SAMPLE RETURN
In a recent survey, none of the other flagship mission concepts studied in detail included Mars except the ongoing Mars Sample Return campaign. Christensen claimed, “Our recommendation is that sample return is the highest scientific priority of NASA’s robotic mission, and Mars sample return should be completed as soon as possible with no changes in its current design. Looking back over the last 20 to 30 years, Mars exploration has clearly figured very prominently in NASA’s planetary exploration program.”