Nasa: scientists want to explore Uranus and land on Enceladus, a moon of Saturn

After the ten-year report on astronomy and astrophysics for the period 2023-2032, unveiled in November 2021, the National Research Council of the United States has just released its ten-year report on planetary science andastrobiology. This new report explores key questions in planetary science, in order to help NASA define its priorities in matter of exploration for the decade 2023-2032.

The ten-year reports of this prestigious institute are eagerly awaited by the American scientific community. A kind of compass, they are strong indicators of the lines of research and orientations of NASA’s ten-year strategies in the fields concerned. They therefore direct several billion dollars of funding towards destinations identified as presenting major scientific interests.

This new report has identified Uranus and Enceladus as two priority targets. Before choosing Uranusthe Scientific Committee – which wrote this ten-year report – evaluated the possibilities of missions to Neptune and Uranus but concluded that a mission to Uranus was preferable. None of the mission concepts reviewed could be implemented in the decade 2023-2032 with the launchers currently available. The report therefore recommends sending a probe around Uranus to study the planet, its rings and its moons. Thus, a probe would be deployed in theatmosphere of the planet which was visited only once by Voyager 2 in 1986. The mission, whose cost is estimated at 4.2 billion dollars, could be launched as early as 2031 aboard a Falcon Heavy of SpaceX and would reach Uranus in just 13 years and using thegravity assist of Jupiter.

Discover life in the recesses of the surface of Enceladus

Regarding Enceladus, the mission concept retained by the report is very ambitious with an orbilander probe whose main objective will be to study the plumes of gas and particles, coming from its underground ocean, which are projected into space. In addition, the conditions prevailing on Enceladus make it possible to directly study the habitability of an oceanic world and determine if it is inhabited or not. This answers one of the most fundamental questions: is there life beyond Earth and if not, why?

Orbilander would spend a year and a half circling Enceladus and sampling these plumes before landing on the icy surface of this small Saturnian world for a two-year mission to search for evidence of life. The mission, whose cost is estimated at 4.9 billion dollars, could be launched in the late 2030s aboard a SLS launcher or a Falcon Heavy with a landing in the early 2050s.

In the field of Mars exploration, this report recommends that NASA continue its efforts and bring the Martian sample return mission as quickly as possible while staying within a budget of approximately $5.3 billion. This mission had been identified as a priority in the previous ten-year report. This new report gives priority to the mission Mars Life Explorer (MLE). Contrary to Perseverance and MSR which instead focus on extinct bio-signatures, MLE will search for active life forms and assess the habitability of the planet today. This $2.1 billion mission could be launched in the mid-2030s. Regarding exploration robotics of the Moon, the Committee recommends the Endurance-A mission, the objective of which is to cover some 2,000 kilometers around and in the South Pole Aitken Basin and collect a hundred kilograms of samples. The originality of this mission is that these samples will be delivered to astronauts Artemis missions that will take care of bringing them back to Earth. With this rather original comeback strategy, this $1.9 billion mission costs about $1 billion less than a mission that involved both a rover and a sample return craft that could only have returned about two kilograms of lunar material.

Four other mission concepts were reviewed, but the committee refused to approve them due to the costs and technologies required being a little too “cutting edge”. This is a mission to Neptune and landers on Europa (Jupiter’s satellite), on Mercury and on Venus.

The report also identified and selected destinations of great scientific interest for future NASA New Frontiers missions:

• a mission around and on a asteroid centaur;
• return of Ceres samples ;
• return of samples from comet ;
• multiple flyovers of Enceladus;
• Lunar Geophysical Network;
• probe inside Saturn ;
• orbit around Titan ;
• mission on the surface of Venus.

Concretely, the report recommends that NASA select one of its concepts for New Frontiers 6, the selection of which is scheduled for the end of this decade. For New Frontiers 7, the selection of which will take place in the early to mid-2030s, the choice will be made from this list of concepts, with the exception of the one selected for mission number 6 of the program. To this list, the report recommends adding a mission to Tritonone of the satellites of Neptune.

Finally, in the area of ​​planetary defence, the report supports continued work to achieve the goal set by Congress in 2005 of discover and characterize 90% of near-Earth objects (NEO) of at least 140 meters in diameter. However, he recommends that NASA work on discovering as many smaller objects as possible. In this context, the space telescope NEO Surveyor is strongly supported. Weighty support for the mission, the last of which proposed budget for the financial year 2023 reduced the mission’s budget, pushing back its launch by at least two years (2026). After NEO Surveyorthe report recommends carrying out a mission to one of these near-Earth objects, 50 to 100 meters in size, in order to better prepare a response to a threat from a short-range NEO. duration.