Speaker
Description
The Kentucky Re-Entry Universal Payload System (KRUPS) is a university-led program that designs, tests, and flies instrumented orbital re-entry capsules that return flight data for the validation of atmospheric entry models. KREPE-2 successfully demonstrated onboard spectroscopy using a Hamamatsu C12880MA mini-spectrometer coupled to the stagnation region of the thermal protection system, providing time-resolved measurements of shock-layer radiation during atmospheric re-entry.
For KREPE-2, each of the five KRUPS capsules was instrumented with a spectrometer, and recorded the maximum and average emission of six-binned spectra. A physics-based forward model incorporating instrument response, blackbody radiation, atomic and molecular emission, atmospheric effects, and surface albedo is used to interpret these spectrally sparse measurements. Early results imply dominant contributions of Planck radiation from the capsule itself during the initial hypersonic descent, as well as additional species currently under investigation, such as CN, C2, Na, and C, while later measurements become increasingly influenced by atmospheric scattering and ocean albedo.
KREPE-3 expands the program to twelve re-entry capsules equipped, with most of them equipped with wither UV or UV-visible spectrometers, enabling more comprehensive characterization of shock-layer radiation and spacecraft demise. Combined with ongoing Bayesian inversion developments, these unique flight data will support the validation of radiation models and the development of next-generation thermal protection systems.
Summary
This presentation presents the flight spectroscopy results from the KREPE program and discusses how these measurements are being used to better understand the physics of atmospheric re-entry and validate computer models used to design spacecraft heat shields.