First Results from the Endurance Neutral Mass Spectrograph

The Endurance sounding rocket mission launched successfully on May 11th, 2022 from Ny Alesund, Norway to study Earth’s ambipolar electric field and associated potential drop with in situ measurements. This mechanism is a key driver of ionospheric outflow, creating a “polar wind” which flows along open field lines above the poles and transports ions to higher altitudes. A neutral mass spectrograph (NMS) was included in the instrument suite to measure the neutral composition profile of the thermosphere. This will be used as an input to the Polar Wind Outflow Model and will help quantify the effects of collisions on the altitude evolution of photoelectron peaks. The initial composition profile measured by the NMS will be presented, discussed, and compared to the MSIS model.