Effect of envelop thermal radiative properties on the stratospheric super-pressure LTA vehicle helium temperature

Environmental radiations acting on a stratospheric super-pressure sphere lighter-than-air (LTA) vehicle were analyzed, including radiation heat and convection heat. LTA vehicle thermal model was established. Based on the thermal model, the thermal effects on the vehicle were analyzed which include sun radiation, earth albedo and radiation. The effect of thermal pertormance caused by different thermal radiative properties of envelope materials, such as absorptivity, emissivity and the ratio of absorptivity to emissivity was detailedly studied. The result shows that the material which has low ratio of absorptivity to emissivity is the better choice for the vehicle. If two materials have the same ratio, the material which has low absorptivity has better thermal control effect. The conclusion is significantly useful for stratospheric LTA vehicle design and material selection.