Heliophysics Environmental and Radiation Measurement Experiment Suite Integration and Testing

Abstract

- This paper describes the plans, flows, key facilities, components and equipment necessary to fully integrate, functionally test, qualify the Heliophysics Environmental and Radiation Measurement Experiment Suite (HERMES) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC). NASA's HERMES and ESA's European Radiation Sensors Array (ERSA) are the two heliophysics and space weather experiments that will fly on the lunar Gateway. ERSA monitors space radiation at higher energies with a focus on astronaut protection, while HERMES monitors lower energies critical to scientific investigations. The Lunar Gateway is an in-development space station in lunar orbit intended to serve as a solar-powered communication hub, science laboratory, short-term habitation module, and holding area for rovers and other equipment for exploration of the lunar surface. It is a critical component of NASA's Artemis program. It consists of two major modules: the Power and Propulsion Element (by Maxar), that is a high-power, solar electric propulsion spacecraft, and the Habitation and Logistics Outpost module (by Northrop Grumman), that consists of multidirectional docking ports, power distribution and command and control systems, and crew hub. The HERMES Payload (HP) will be installed on the exterior of the HALO module for better science Field of Views (Fo V). HERMES is led by NASA's GSFC, in Greenbelt, Maryland and it consists of four instruments. Three instruments are mounted together on a platform: the Miniaturized Electron pRoton Telescope, or MERiT, which measures ions and electrons; the Electron Electrostatic Analyzer, or EEA, which measures the lower energy electrons that make up most of the solar wind, and the Solar Probe Analyzer for Ions, or SPAN-I, which measures protons and ions including oxygen. MERiT and EEA are provided by GSFC. SPAN - I is built at the University of California, Berkeley. The fourth instrument is the Noise Eliminating Magnetometer Instrument in a Small Integrated System, or NEMISIS. NEMISIS provides interplanetary and magnetotail magnetic field observations in a miniaturized and multi-magnetometer system with a 360-degree field of view. It consists of one fluxgate magnetometer built by GSFC, and two magneto-inductive magnetometers provided by the University of Michigan. The fluxgate magnetometer will be mounted on a stanchion. The magneto-inductive magnetometers will be mounted in two different areas of the platform. The I&T activities consist of mounting and testing the four instruments, the Instrument Control Electronics (ICE) box and the Solar Wind Electronics Module (SWEM) on the HERMES platform. Each of the four instruments, the ICE Box and the SWEM will come to the platform fully qualified and ready for integration. This I&T phase will be followed by the HERMES environmental tests which include electromagnetic interference (EMI)/electromagnetic compatibility (EMC), vibration, thermal balance, thermal vacuum and magnetic test. This paper will briefly discuss HERMES shipment and delivery to the Gateway Program for installation on the HALO module as well as some launch preparation activities.