Europa Clipper: An Overview of the Mission

Europa Clipper was launched on October 14, 2024 to implement NASA’s first detailed exploration of an ocean world. Europa almost certainly contains a global subsurface ocean where a potentially habitable environment could have persisted for millions if not billions of years. The nominal tour of 4.27 years includes about 50 flybys of Europa, some as close as 25 km. The underlying theme of the mission is to search for the building blocks of life that could provide the foundation for a habitable environment. With the likely existence of other ocean worlds in the Solar System, including Titan, Enceladus, Ganymede, Ceres, and potentially many more in other solar systems, the detailed exploration of Europa takes on prime importance.

The main objectives of the mission are to characterize the ice shell and any subsurface water, including their heterogeneity, ocean properties, and the nature of surface–ice–ocean interactions; understand the habitability of Europa’s ocean through composition and chemistry; and understand the formation of surface features, including sites of recent or current activity, and characterize high science interest localities. A final cross-cutting objective is to search for current activity.

   The mission’s objectives will be addressed with an advanced suite of complementary instruments. The remote sensing payload consists of the Europa Ultraviolet Spectrograph (Europa-UVS), Europa Imaging System (EIS), Mapping Imaging Spectrometer for Europa (MISE), Europa Thermal Imaging System (E-THEMIS), and Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON). The in-situ instruments are the Europa Clipper Magnetometer (ECM), Plasma Instrument for Magnetic Sounding (PIMS), SUrface Dust Analyzer (SUDA), and MAss Spectrometer for Planetary EXploration (MASPEX). Gravity and Radio Science (G/RS) will be achieved using the spacecraft's telecommunication system, and valuable scientific data of the radiation environment will be collected by the engineering sensors comprising the Radiation Monitor (RadMon). All instruments will be operating together, with the remote sensing instruments pointed to nadir and the in-situ instruments pointing in the ram direction. With a total ionizing dose of 2.97 Mrads, one of the challenges of the missions is to protect the instruments’ electronics from damaging radiation. The main mitigation tactic was to encase most of the electronics in a metal vault. Another operational mitigation is to orbit Jupiter rather than Europa, and swoop into the more dangerous environment of high energy particles at Europa only for encounters.

The cruise period is about five and a half years, providing a long period to check out and calibrate the instruments, as well as to optimize the science planning process for the tour. Initial checkouts and activities have been successful, with minor problems corrected. The interplanetary trajectory includes two gravity assists: one at Mars, which occurred on March 1, 2025, and another at Earth, which will occur on December 3, 2026.  The Mars flyby provided an opportunity for key calibrations for E-THEMIS; an end-to-end test of REASON; and checkouts of all the telecommunication components necessary for the G/RS experiment. Although all data are not on the ground as of early May, the indications are that these activities were successful. More activities are being planned for the Earth-flyby. Jupiter Orbit Insertion occurs on April 11, 2030, with an initial flyby of Ganymede on October 30, 2030. The first flyby of Europa will occur on March 7, 2031 with a closest approach of just over 200 km.

During most of the period of the Europa Clipper mission, the European Space Agency (ESA) will be operating the highly complementary Jupiter Icy Moons Explorer (JUICE) mission. JUICE will focus on Callisto, Ganymede, and fields and particles in the vicinity of Jupiter. Although only two flybys of Europa will occur as part of the mission, one will happen almost simultaneously with one of Europa Clipper’s flybys. These coordinated flybys will offer an unprecedented opportunity to understand the Jovian system at a very large spatial scale. The two science teams have begun informal collaborations to consider synergistic science opportunities during this key period, as well as during cruise and approach.

Following the success of the efforts established by other missions, the Europa Clipper science team includes a ground-based astronomical observers support group. The purpose of this group is to provide follow-up for transient events; to offer greater temporal and spatial context; and to obtain wavelengths and viewing geometrics not observed by Europa Clipper.  

The Europa Clipper team has published articles on the mission, instruments, and engineering systems in an open-access topical collection of the journal Space Science Reviews. The team has begun science observation planning for both nadir and non-nadir periods of the nominal tour to sketch out a Strategic Science Planning Guide, which details the science observation strategy. This presentation will provide any late updates, particularly those involving the recent gravity assist at Mars.  

Government support acknowledged.