The enhanced Ion and Neutral Mass Spectrometer for the PetitSat CubeSat mission

Sarah Jones ¹ Nikolaos Paschalidis ¹ Timothy Cameron ³ Paulo Uribe ² Marcello Rodriguez ² Dennis Chornay ⁴ Kenth Santibanez Rivera ² Edward Sittler ¹

¹Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD, USA
²Applied Engineering and Technology Directorate, NASA Goddard Space Flight Center, Greenbelt, MD, USA
³Adnet Systems Inc., Adnet Systems Inc., Greenbelt, MD, USA
⁴University of Maryland, College Park, University of Maryland, College Park, College Park, MD, USA

There is great need for in situ measurements of atmospheric ion and neutral composition and density due to a dearth of measurements since the DE satellite mission ~30 years ago. The Ion and Neutral Mass Spectrometer (INMS) seeks to fill this void while achieving several measurement firsts and enabling new scientific studies, including constellation missions. INMS is a tiny, versatile time of flight spectrometer that measures atmospheric composition within a 1.1 U volume, approximately 0.5 kg and 1.8 W nominal power. INMS is based on front-end optics including thermionic emission ionization, pre-acceleration, gated time of flight (TOF), electrostatic analyzer (ESA) and channel electron multiplier (CEM) detectors. The compact sensor has a dual symmetric configuration with sensor heads on opposite sides of shared electronics. INMS measures in situ ions and neutrals (H, He, N, O, N2, O2) with M/dM of approximately 12 and has been successfully demonstrated in space as part of the ExoCube and Dellingr CubeSat missions. An upgraded version of the instrument has been delivered for flight on the ExoCube2 mission in late 2019 and an instrument with two redundant neutral apertures will be flown on the PetitSat mission in 2020. This presentation will provide a description of the INMS design, including upgrades for upcoming missions.