Carbon dioxide intensity emitted in the infrared spectral range is deemed to be a significant contributor to the radiative heat flux withstood by spacecraft during its entry into Martian atmosphere at entry speeds lower than 5km/s. While shock layer CO2 radiative properties characterization received significant attention over the last decades, its spectral distribution in the wake region suffers from large uncertainty. Therefore, in this study, infrared radiation intensity and spectrum have been measured in the hyper-velocity expansion tube (HVET) facility developed in JAXA Chofu Aerospace Centre. First, in order to estimate the test flow conditions, time histories of pitot pressure are measured. Second, the radiation intensity distributions in VIS and IR wavelength region are obtained. Finally, IR radiation spectrum in front of, behind and without a Mars entry aeroshell model are measured.
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