Haje Korth

NASA’s Europa Clipper mission is on course to begin its investigation of the Jovian system in 2030, where it will assess Europa’s potential habitability through a coordinated suite of remote-sensing and in-situ measurements. While the mission’s primary science campaign lies ahead, the cruise phase provides opportunities to commission flight hardware, refine operational concepts, and conduct initial calibrations and performance tests under conditions that cannot be fully reproduced on the ground. The Mars-Earth gravity-assist trajectory therefore serves both as a means of reaching Jupiter, and as an important step in preparing the observatory for the demanding environment and tightly coordinated operations required at Europa.Europa Clipper launched on 14 October 2024 and completed its Mars gravity assist on 1 March 2025. That encounter enabled early in-flight validation across several investigations: The Europa THermal EMission Imaging System (E-THEMIS) acquired Mars observations to support validation of a nonlinearity correction for one thermal band, the Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) performed its first complete end-to-end radar test through closest approach, and the Gravity and Radio Science (G/RS) team exercised flyby gravity science tracking procedures with open-loop receivers from NASA’s Deep Space Network. Then in November 2025, the Europa Ultraviolet Spectrograph (Europa-UVS) observed interstellar comet C/2025 N1 ATLAS near the comet’s closest approach to Earth, obtaining data useful ultraviolet data for calibration and compositional assessment. Finally, the Europa Clipper Magnetometer (ECM) and the Plasma Instrument for Magnetic Sounding (PIMS) have been operating regularly in cruise to mitigate technical risk and to facilitate frequent solar wind calibrations. These activities demonstrate how cruise operations can reduce risk, improve instrument characterization, and produce scientifically useful measurements prior to Jupiter arrival.The mission’s Earth flyby on 3 December 2026, will provide a more comprehensive rehearsal of Europa Clipper’s payload and spacecraft capabilities. Earth’s well-characterized magnetic, plasma, atmospheric, thermal, optical, and radiation environments offer a uniquely valuable calibration and operational target. The encounter will support absolute calibration of ECM using Earth’s magnetic field and crosscalibration of the PIMS Faraday cup measurements against plasma observations from other near-Earth spacecraft.Additional calibrations and characterizations are being considered for implementation. REASON could use terrestrial lightning over the Amazon and/or Africa to characterize the radar beam pattern and could test receiver performance using transmissions from Owens Valley Radio Observatory. Within the Van Allen radiation belts, the Europa Imagin System (EIS) could acquire visible camera observations despite its cover being closed, to evaluate susceptibility to a radiation environment that is a precursor to future operations at Jupiter. E-THEMIS could use Earth and Moon observations, coordinated with Europa-UVS whenever possible, to calibrate its extended thermal range and to validate radiometric performance using the cold lunar nightside, the only pre-arrival target approaching Europa-relevant low temperatures. Europa-UVS could test stellar occultations of UV-bright stars by Earth and the Moon to prepare for probing Europa’s atmosphere and could observe terrestrial airglow near closest approach as an analog for future Europa measurements. Europa-UVS, E-THEMIS, EIS, and the Mapping Imaging Spectrometer for Europa (MISE) infra-red spectrometer could conduct a joint-scan demonstration of coordinated multi-instrument pointing, despite the EIS and MISE covers being closed.Additional spacecraft and payload activities could broaden the encounter’s value as an operational test. Star-tracker imaging of Earth could test whether engineering sensors can provide scientifically useful data products. Check-outs of the SUrface Dust Analyzer (SUDA) dust analyzer and the MAss Spectrometer for Planetary Exploration (MASPEX) neutral gas mass spectrometer could assess instrument compatibility and operational behavior in the modest radiation environment near Earth. G/RS Doppler tracking could test telecommunications modes and antenna switching, while RadMon radiation monitor and the Canary Box MOSFET transistor monitor will characterize the performance of these engineering subsystems in the Earth’s Van Allen belts.Together, the Mars and Earth gravity-assist activities, opportunistic cruise observations, and coordinated calibration campaigns form an end-to-end preparation program for Europa Clipper. By validating instrument performance, testing coordinated operations, and exposing spacecraft systems to relevant natural environments before Jupiter arrival, these cruise-phase activities increase confidence that the observatory will be ready to execute its Europa science campaign and address the mission’s central objective: determining whether Europa has conditions suitable for life.

The arrival of NASA's Europa Clipper at the Jovian system in the coming years marks a pivotal moment for ocean world science. While the mission is designed to transform our understanding of Europa's habitability, cruise phase operations are already delivering important progress toward maturing operations concepts, validating instrument performance, and enabling early synergistic measurements that will strengthen the eventual science return.The Europa Clipper spacecraft was launched on 14 October 2024 and executed a gravity assist maneuver at Mars on 1 March 2025, which enabled early tests of three key investigations. E-THEMIS observed Mars to validate a nonlinearity correction algorithm. REASON conducted its first complete end-to-end test at closest approach, which had not been possible before launch due to system integration constraints. G/RS evaluated flyby tracking procedures using open-loop receivers from NASA's Deep Space Network. Following successful completion of all Mars activities, the Europa-UVS instrument observed interstellar comet C/2025 N1 ATLAS near its Earth closest approach on 6 November 2025, from a distance of about one astronomical unit. The acquired data served to calibrate the instrument and provided information on the comet’s composition.Before entering the Jovian system in 2030, the spacecraft will perform a second and final gravity assists at Earth on 3 December 2026 to target Jupiter. The Earth flyby will allow the only post-launch absolute calibration of the Europa Clipper Magnetometer (ECM) using Earth’s magnetic field. It will also support cross-calibration of PIMS through comparison with data from other near-Earth spacecraft. Under consideration are additional activities, which would be valuable to test operations of multiple instruments and spacecraft system in parallel. Throughout cruise, periodic checkouts verify functionality and, in some cases, enable unique scientific measurements in the heliosphere.Coordination with ESA's JUICE mission has created potential for synergistic science that could enhance our understanding of solar wind dynamics and Jovian system interactions. Together, these activities lay the foundation for fully calibrated payload, which is essential to achieving Europa Clipper's overarching goal of evaluating Europa’s habitability.

Mercury is the only planetary magnetosphere which does not possess a conducting ionosphere, yet magnetic field observations by the Mariner 10 and MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) missions revealed a stable presence of large-scale field-aligned currents (FACs). Several empirical magnetic field models have been developed to describe Mercury’s magnetospheric currents and their associated magnetic fields, but none attempted to include an explicit description of large-scale FACs. Here, we describe a dynamic FAC magnetic field model for Mercury based on the analytical solution to conical currents, which are shielded by a dynamic magnetopause boundary. The model contains free parameters setting the FACs’ latitudinal extent and amplitude as functions of magnetospheric activity. The parameters are fit by minimizing the root-mean-square (RMS) differences between the model and MESSENGER Magnetometer data. During magnetically quiet conditions, the modeled FACs have an intensity of ~10 nA/m2 and extend in latitude from ~83° N to ~40° N. They intensify to ~20 nA/m2 and expand equatorward to ~28° N during the most active times. The inclusion of the FAC model reduces low-altitude RMS residuals by 8.1% when compared to prior models. The model effectively captures the azimuthal component of the magnetic field present in the MESSENGER low-altitude data, but largely misses the radial and co-latitudinal components, indicating other large-scale physics remain missing in the mathematical descriptions of Mercury’s magnetosphere.

NASA’s Europa Clipper and ESA’s Jupiter Icy Moons Explorer (JUICE) missions are each currently bound to explore the Jupiter system during overlapping time periods in the early 2030s. Europa Clipper is scheduled to arrive in orbit around Jupiter in April 2030, followed by JUICE’s arrival in July 2031. While each mission was designed to pursue its own set of independently compelling science objectives, the temporal and spatial proximity of these two well-instrumented spacecraft presents an unprecedented opportunity to perform coordinated or complementary scientific observations across the Jovian system. The scientific return from such joint activities has the potential to exceed significantly the sum of each mission’s individual efforts.Recognizing this potential, a JUICE–Clipper Steering Committee (JCSC) was formed jointly by the two mission teams to identify and evaluate possible synergistic science opportunities. This committee includes members from both missions, and it has drawn on science team input from multiple joint workshops, as well as the Science Traceability Matrix developed for the earlier Europa Jupiter System Mission (EJSM) study. The JCSC recently provided a set of recommendations to the two mission teams, describing science themes and observation strategies that could benefit from joint implementation. The recommendations for the orbital (tour) period include time-dependent and space-dependent coordinated measurements of Europa, Ganymede, Callisto, Io, Jupiter’s magnetosphere and atmosphere, the ring system, and small satellites. The next step is for each mission to consider which of the proposed activities may be realistically implementable within the scope of its mission constraints. Within the Europa Clipper project, which currently focuses on Europa science only, a structured internal assessment is currently underway to evaluate which synergistic science opportunities could potentially align with the mission’s priorities, resources, and operational design.The Europa Clipper mission, launched in October 2024, is guided by the mission's goal of assessing the habitability of Europa. The mission’s three science objectives are to characterize the ice shell and subsurface structure, characterize the composition and chemistry of the surface and exosphere, and elucidate geological activity and recent surface processes; cross-cutting these is to search for and characterize current activity such as plumes and thermal anomalies. The spacecraft will conduct nearly 50 flybys of Europa at altitudes as low as 25 km over a four-year nominal tour, while also executing opportunistic flybys of Ganymede and Callisto. Europa Clipper carries a sophisticated suite of nine science instruments—spanning imaging, spectroscopy, magnetometry, radar sounding, dust analysis, and mass spectrometry—as well as gravity and radio science supported by the telecommunications system.Because the mission is complex and constrained by the high-radiation environment of Jupiter, the incorporation of new science activities, even those of high potential value, must be approached with careful evaluation of resource and cost feasibility. Accordingly, Europa Clipper’s internal response to the JCSC recommendations is being developed through a collaborative, phased process led by the Project Scientist.In the first phase of this process, each of Europa Clipper’s ten Investigation Teams was asked to review the JCSC’s Orbital Report and provide instrument-specific assessments of the scientific value, technical feasibility, and operational implications of the proposed joint observations, and to identify any additional key opportunities that may warrant consideration. These assessments addressed instrument-specific observation opportunities and constraints.In the second phase, Europa Clipper’s three Objective-based Thematic Working Groups (Interior, Composition, and Geology) were tasked with synthesizing the instrument-level inputs and identifying which opportunities offer the most compelling science return, considering associated constraints. This cross-disciplinary analysis ensures that the evaluation is anchored in integrated science value.This process also includes coordination with Europa Clipper’s Mission System team, to evaluate the technical and operational feasibility of candidate observations. The Mission System team is advising on resource availability and limitations in areas such as power, spacecraft pointing and slewing capabilities, BDS (bulk data storage) capacity, and downlink availability. Because Europa Clipper operates in a radiation-intense environment and executes carefully choreographed flybys, even small changes to the mission plan could have significant impacts on spacecraft operations, science acquisition, and data return. As such, potential synergistic activities must be thoroughly vetted to ensure they do not compromise the mission’s primary objective or over-extend mission resources.With this mission-internal assessment, the Project Scientist and Deputy Project Scientists—working in consultation with the JCSC Facilitator—will prepare a recommended package of synergistic observations that Europa Clipper may be able to support. This recommendation will be presented to the full Science Team for discussion and refinement, ensuring that it reflects both broad consensus and careful prioritization. The final recommended set of activities will be shaped by two overarching criteria: (1) scientific significance in the context of Europa Clipper’s science objectives and capabilities, and (2) simplicity and realism of implementation within the mission’s resource envelope.By the time of the joint EPSC/DPS 2025 meeting, this process is expected to be substantially complete. At the EPSC/DPS 2025 meeting, we will present the results of Europa Clipper’s internal evaluation, including...

Europa Clipper, NASA’ s flagship planetary mission launched on 14 October 2024, is now en route to Jupiter' s ocean-world Europa via gravity assist maneuvers at Mars (accomplished on 1 March 2025) and Earth (scheduled for December 2026). Two of the ten instruments on board are the Plasma Instrument for Magnetic Sounding (PIMS) and the Europa Clipper Magnetometer (ECM), which will accurately determine Europa' s subsurface ocean thickness, conductivity (a proxy for salinity), and ice shell thickness. During Europa Clipper' s outbound transit between Earth and Mars, PIMS was activated for the first time since launch to assess its post-launch health on 19 December 2024. At this time, ECM was also on to monitor potential magnetic interference from instrument and spacecraft checkout activities from 22 November 2024 to 22 January 2025. During the one hour that PIMS was on and run in science mode, it detected anomalous solar wind plasma, which turned out to be in the wake of a coronal mass ejection (CME). The CME was also detected by 15 other observatories throughout the heliosphere between 0.94 AU (Solar Orbiter) and 1.60 AU (MAVEN) in a fortuitous alignment with Europa Clipper. This unprecedented number of observatories (16 total) and configurations enable a deeper understanding of the structure and evolution of a complex CME in interplanetary space between approximately 0.9 AU and Mars. The observations revealed that the CME component that impacted Earth, Europa Clipper, and Mars went completely unnoticed by the remote sensing observatories along the Sun- Earth line, but was captured in considerable detail by the STEREO- A imagers located 30 deg west of Earth. This unique multi- point analysis showed that the CME was strongly asymmetric in ecliptic longitude, which is highly atypical and particularly concerning for robust space weather forecasting. The array of observatories involved in this extraordinary event underscores the critical importance and need for multipoint remote sensing and in situ observatories to enable accurate space weather predictions. In this respect, Europa Clipper fills a significant gap of heliophysics observatories between Earth and Mars, making it an exceptional asset for characterizing space weather with PIMS and ECM – a task increasingly important as humanity strives to send astronauts to Mars in the future. Our results demonstrate the invaluable advantage of a cross- divisional strategy employing observatories from both the planetary and heliophysics communities to efficiently and cost-effectively maximize the space weather benefits and scientific return from those missions.

Launched on 14 October 2024, the Europa Clipper mission represents a pivotal endeavor in planetary exploration, aimed specifically at studying the habitability of Jupiter’s moon Europa. During its cruise phase, the spacecraft will conduct gravity assist maneuvers at both Mars and Earth before arriving in the Jovian system in 2030, where it is scheduled to perform a series of 49 flybys of Europa, along with additional encounters with Ganymede and Callisto. These gravity assists are instrumental in refining the spacecraft’s trajectory and optimizing the calibration of some of its scientific instruments prior to the primary mission phase, underscoring the importance of the cruise period as a preparatory stage for the core observational efforts.The Mars gravity assist on 1 March 2025 provided an opportunity to calibrate and test three Europa Clipper investigations. First, the Europa Thermal Emission Imaging System (E-THEMIS) thermal instrument acquired data on Mars as a well characterized source, to test an algorithm that corrects a nonlinearity in one of the instrument’s wavelength bands. These observations occurred one day prior to closest approach and near in time when the same region was measured by the THEMIS instrument on Mars Odyssey, which is heritage for E-THEMIS. Second, the Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) ice-penetrating radar performed its first comprehensive end-to-end test by operating at closest approach. Due to technical limitations and flow of the flight system integration process, it was not possible to complete such test prior to launch. As a reference for comparison, the Shallow Radar (SHARAD) sounder on the Mars Reconnaissance Orbiter (MRO), which is heritage for REASON, obtained data of the same area 20 minutes later. Finally, the Gravity and Radio Science (G/RS) team tested flyby procedures and processes using the open-loop receivers of the Deep Space Network (DSN). At the time of writing of this abstract, the E-THEMIS and REASON data have not been received due to limitation in the bandwidth of the spacecraft communication. The data are anticipated to be transmitted to ground by June 2025.The Earth gravity assist will occur on 3 December 2026. This encounter will enable the one and only absolute calibration of the Europa Clipper Magnetometer (ECM) post launch by flying through Earth’s well-characterized magnetic environment. Existing space assets near Earth will also allow for cross-calibration of the Plasma Instrument for Magnetic Sounding (PIMS) through comparison of observed charged particles populations, which are difficult to faithfully reproduce in a laboratory environment prior to launch. Additional instrument operations are presently under discussion. While these observations are not critical to the functioning of the payload, the Earth encounter offers a unique opportunity for the mission operations team to test simultaneous operation of multiple instrument and flight system components in preparation for the primary mission.Finally, throughout the cruise phase, the mission’s scientific instruments must be exercised periodically to verify functionality and for calibrations purposes. For select instruments, notably ECM and PIMS, these operations enable the collection of complementary data of their heliospheric and magnetospheric environment as the spacecraft transitions through varying interplanetary conditions. The coordination of the Europa Clipper mission with the European Space Agency’s Jupiter Icy Moons Explorer (JUICE) has further created unique opportunities for joint interactive science during the joint cruise phase and beyond. Such collaboration could potentially enhance our understanding of broader dynamics in the solar wind and within the Jovian system while employing complementary observational strategies.Collectively, the planned and already executed activities during the cruise phase of the Europa Clipper mission will set the stage for detailed analysis upon arrival in the Jovian system, ultimately enhancing our understanding of one of the solar system’s foremost candidates for habitability. At Europa, the anticipated scientific observations will include characterizing the ice shell and subsurface ocean properties, determining the surface and atmospheric composition, and understanding the formation of geological features at the surface. A well-working and fully calibrated payload is a prerequisite for achieving these science objectives and the mission’s overarching goal to investigate Europa’s habitability.

On 14 October 2024, NASA’s Europa Clipper spacecraft was successfully launched from Kennedy Space Center with the goal to explore Jupiter’s moon Europa to investigate its habitability. A key investigation to achieve this goal is the characterization of the moon’s ice shell and global subsurface ocean using induced magnetic fields observed by the Europa Clipper Magnetometer. The Europa Clipper Magnetometer (ECM) consists of three three-axis fluxgate magnetometers mounted in gradiometer configuration on an 8.5 m-long, coilable boom. With the instrument checked out and all three sensors sampling the magnetic field at 16 vector samples per second, the magnetometer boom was deployed on 5 November 2024. The acquired data demonstrate that the boom deployed successfully to its full length. In addition, the observations obtained during the boom extension provide the first insight into the spacecraft magnetic field post launch and represent the only measurements of a quasi-radial profile of these contamination fields. As such, they are critical for the validation of a detailed, multi-pole magnetic model of the spacecraft, which was established pre-launch during the hardware integration and test phase of the mission. Initial results show that the observations compare favorably with the magnetic model consisting of 240 individual offset dipoles and that the magnetic cleanliness requirement to limit the spacecraft magnetic field at the outboard sensor to less than one nanotesla is met. Finally, corrected for the spacecraft field, the ECM observations provide the spacecraft’s first observations of the interplanetary magnetic field enroute to Mars, where Europa Clipper will execute a gravity assist maneuver. In this presentation, we report the first magnetic field measurements by the Europa Clipper Magnetometer, assessment of the spacecraft magnetic field, comparison with the spacecraft magnetic model, and ultimately the first observations of the magnetic field in the solar wind by Europa Clipper.

Europa Clipper launched on October 14, 2024 and is now en route to Europa to study this icy moon with a subsurface ocean. Characterizing Europa’s subsurface ocean is critical to assess its habitability – the primary goal of the Europa Clipper mission. The Plasma Instrument for Magnetic Sounding, or PIMS, consists of 4 Faraday cups (Ram, Zenith, Anti-ram, Nadir) on 2 sensors (PIMS Upper and PIMS Lower) located on opposite sides of Europa Clipper. PIMS measures the current induced by plasma particles with sufficient E/q to make it through a modulated grid placed at AC high voltage (HV). The HV waveform applied to the modulator grid consists of a DC level and a sine wave with a pre-set amplitude; thus, the particles that can pass through the grid produce an AC current. PIMS will characterize the plasma in Europa’s magnetic environments, which will allow for the subtraction of the plasma contribution from the magnetic induction signal measured by the Europa Clipper Magnetometer (ECM). Subtracting the plasma contributions from the induced field measurements will provide a more accurate derivation of the ocean depth and conductivity, and ice shell thickness.PIMS was powered on for the first time since Europa Clipper’s launch in December 2024. While the goal of this checkout was to assess PIMS’s post-launch health, a welcome surprise was the detection of a coronal mass ejection (CME) by the Zenith cup on PIMS Upper. This fortuitous detection was made during only a ~1-hour period that PIMS was running in science mode. Several other observatories also observed this CME, including MMS and the L1 constellation at Earth, and STEREO-A elsewhere at 1 AU. These observations along with PIMS on Europa Clipper allow for some rare multipoint analysis of the size, shape, and propagation of this CME.The solar cycle is currently at maximum with an increased number of solar events driving space weather effects in geospace around Earth and beyond. These “first light” measurements clearly demonstrate the importance of PIMS, and Europa Clipper, as a working asset for understanding space weather in the Earth-Mars region – a region of space otherwise lacking instrumentation for these measurements. CMEs are the biggest space weather hazards for astronauts, which makes turning PIMS and ECM on and having them collecting data during Europa Clipper’s interplanetary cruise phase all the more important.

NASA’s Europa Clipper spacecraft successfully launched on 14 October 2024, on its interplanetary journey to Jupiter, where it will repeatedly encounter Europa during low-altitude (generally 25–100 km) flybys designed to enable exploration of the satellite and investigate its habitability. Europa Clipper’s 5.5 yr cruise includes gravity assists at Mars (1 March 2025) and Earth (1 December 2026). The spacecraft will enter orbit around Jupiter (11 April 2030) and will perform 49 science flybys of Europa over a 4.3-yr Jovian tour.To explore Europa as an integrated system and achieve a complete picture of its habitability, the Europa Clipper mission has three main science objectives: Characterization of: (1) the ice shell and ocean including their heterogeneity, properties, and surface–ice–ocean exchange; (2) Europa’s composition including any non-ice materials on the surface and in the atmosphere, and any carbon-containing compounds; and (3) Europa’s geology including surface features and localities of high science interest. Additionally, several cross-cutting science topics will be investigated through searching for any current or recent activity in the form of thermal anomalies and plumes, performing geodetic and radiation measurements, and assessing high-resolution, co-located observations at select sites to provide reconnaissance for a potential future landed mission. These science objectives will be accomplished using a highly capable suite of remote-sensing and in-situ instruments. The remote sensing payload consists of the Europa Ultraviolet Spectrograph (Europa-UVS), the Europa Imaging System (EIS) consisting of a wide and a narrow angle camera (WAC, NAC), the Mapping Imaging Spectrometer for Europa (MISE), the Europa Thermal Imaging System (E-THEMIS), and the Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON). The in-situ instruments are the Europa Clipper Magnetometer (ECM), the Plasma Instrument for Magnetic Sounding (PIMS), the SUrface Dust Analyzer (SUDA), and the MAss Spectrometer for Planetary Exploration (MASPEX). Gravity and radio science will be obtained using the spacecraft’s telecommunication system, and valuable scientific data will also be acquired by the spacecraft’s radiation monitoring system.As of this writing, the spacecraft is performing extremely well on its way toward the Mars gravity assist. Deployments of the ECM boom and REASON antennas has been successful. All initial subsystem and instrument functional checkouts are complete and also have been a success. The Europa Clipper team is nearing completion of publication of a set of manuscripts in a topical collection of Space Science Reviews, and the science team continues to work towards optimizing science return through preparation of the mission’s Strategic Science Planning Guide. Joint discussions continue on potential opportunities for unique collaborative science with ESA’s JUpiter ICy moons Explorer (JUICE) mission, which will overlap in its tour period at Jupiter.This work is supported by NASA through the Europa Clipper Project.