Speaker
Description
Background of the Study
Aerocapture is a flight manoeuvre to enable orbit insertion by using the atmosphere to decelerate a spacecraft more mass efficiently than a typically used orbit insertion burn. The flight manoeuvre is of particular interest for missions to the ice giant planets as it could significantly reduce the interplanetary travel time.
However, aerocapture was never performed to this date, and no spacecraft has yet entered the atmosphere of an ice giant planet. State of the art numerical methods predict harsh flight conditions for such a mission, but still ablative heat shield materials are theoretically capable of handling the expected loads.
The atmospheric density and composition of the ice giant planets is not known precisely, which motivates a planetary probe mission to these planets in the first place. Whether the predictions for the atmospheric composition and the resulting load onto the spacecraft are correct, can only be verified by including a sensor-suite into the spacecraft’s Thermal Protection System (TPS).
Methodology
A sensor-suite is designed to be embedded into the ablative TPS of a spacecraft flying to the ice giant planets. Next to temperature and pressure gauges, this sensor-suite includes a miniature spectrometer. Challenges for such an instrument are optical access, extreme thermal loads, and potential signal contamination from pyrolysis gases.
A breadboard system is manufactured and tested in the plasma wind tunnel facility PWK4 at ice giant aerocapture peak heating conditions in multiple experiments.
Results
The sensor-suite’s instrumentation is operational throughout the entire duration of the ablation experiments. The data recorded is reproduceable between experiments and generally follow the expected trends.
Data from the miniature spectrometer is validated against the measurements from a high-resolution laboratory spectrometer.
Summary
A TPS embedded sensor-suite for ice giant aerocapture is designed and successfully validated in an experimental plasma wind tunnel test campaign at peak heating test conditions. Results from these experiments provide valuable data which gives confidence in the functionality of the sensor-suite and enables a deeper analysis of the plasma flow.