Thermospheric Drag Sondes: on-demand probes of the lower Thermosphere/Mesosphere system
Abstract
The Thermospheric Drag Sonde (TDS) is a system concept designed to provide multiple, affordable, and expendable thermosphere/mesosphere probes in a compact format that can be stored on space stations, like the International Space Station (ISS), and launched on demand. The motivation for the concept is the lack of data on the lower ionosphere/thermosphere/mesosphere (ITM) system (~100 - 300 km AMSL) and the difficulty in sustaining orbital platforms at these very Low Earth Orbit (VLEO) altitudes for periods sufficient to sample a wide variety of conditions in geospace. The TDS concept takes its inspiration from upper atmospheric radiosondes that are launched on demand on balloons to provide critical data for terrestrial weather forecasting models. The recent loss of forty SpaceX Starlink satellites due to unexpectedly large atmospheric drag increases at their staging altitude of 210 km during a minor geomagnetic storm emphasizes the need for improved forecasting and nowcasting information at VLEO altitudes. Probe-on-demand systems such as the TDS would fill a key gap in ITM science and data assimilation in forecasting models. A single TDS consists of a compact storage format that deploys into large, lightweight satellite equipped with one or more accelerometers to directly measure drag effects, a dual-frequency GNSS receiver, a compact radio link, and a passive de-orbit system that enables prompt re-entry after deployment from the ISS. Utilizing innovative spherical profile technology to simplify coefficient of drag calculations, TDS deployments will obtain acceleration and GPS Precise Orbit Determination (POD) data during descent and re-entry, providing neutral density profiles for novel science investigations of the ITM system, forecast model data assimilation, and nowcasting data to inform launch operations. The concept is in development with a notional deployment to the ISS in the 2026 timeframe.
- Publication:
-
44th COSPAR Scientific Assembly. Held 16-24 July
- Pub Date:
- July 2022
- Bibcode:
- 2022cosp...44..804B