The Particle Environment Package (PEP) for the JUICE mission: Ready to go!

<p><strong>1. PEP objectives</strong></p> <p>The PEP suite explores the particle populations in the Jovian system to answer three overarching science questions:</p> <p>(1) How does the corotating magnetosphere of Jupiter interact with Ganymede, Callisto, Europa, and Io?</p> <p>(2) How do internal and solar wind drivers cause such energetic, time variable and multi-scale phenomena in the steadily rotating giant magnetosphere of Jupiter?</p> <p>(3) What are the structure and composition of the icy moons exospheres and how do they response to the external conditions?</p> <p> </p> <p><strong>2. PEP suite</strong></p> <p>PEP measures positive and negative ions, electrons, exospheric neutral gas, thermal plasma and energetic neutral atoms present in all domains of the Jupiter system over nine decades of energy from < 0.001 eV to > 1 MeV with full angular coverage. The six PEP sensors are:</p> <ul> <li>Jovian plasma Dynamics and Composition analyzer (JDC);</li> <li>Jovian Electrons and Ions analyzer (JEI);</li> <li>Jovian Energetic Electrons (JoEE);</li> <li>Jovian Energetic Neutrals and Ions sensors (JENI);</li> <li>Jovian Neutrals Analyzer (JNA);</li> <li>Neutral gas and Ion Mass spectrometer (NIM).</li> </ul> <p>For the first time at Jupiter PEP combines global imaging via remote sensing using ENAs with in-situ measurements and performs global imaging of Europa/Io tori and magnetosphere combined with energetic ion measurements. Using low energy ENAs originating from the particle – surface interaction PEP investigate space weathering of the icy moons by precipitation particles. PEP will first-ever directly sample the exospheres of Europa, Ganymede, and Callisto with high mass resolution.</p> <p><img src="" alt="" /></p> <p>Figure 1: PEP suite and PEP sensors</p> <p><strong>3. PEP ready to go</strong></p> <p>All flight models of the PEP sensors and electronics as well as central processing unit and common power supply system have been tested, qualified, and calibrated. The complete model was delivered to ESA and ready for launch in April 2023. All sensors performance fulfilles the mission requirements. PEP will provide the most comprehensive simultaneous measurements of the plasma and neutral gas environment in the Jovian system and at the Galilean moon.</p>