Beijing – A new polyurethane foam insulation in China is designed to reduce propellant evaporation in cryogenic rockets. The new product can raise insulation performance by 50% compared with conventional foam materials.
PU insulation cools China’s cryogenic rockets

This information came from the China Academy of Launch Vehicle Technology. The institute is affiliated to the China Aerospace Science and Technology Corporation (CASC).
According to CASC, cryogenic rockets are typically fuelled by liquid hydrogen and liquid oxygen. Such fuels are greener, more energy efficient and less costly than other fuels. But their evaporation loss is a major contributor to the rocket’s short orbital period – they can only orbit for a few hours.
Another newly developed variable density multilayer insulation material is used along with the new PU in the rockets. This combination of materials is combined with a new pressure relief method for the propellant tank. The design change can bring down the overall evaporation rate from 2.5%/day to 0.5%/day, according to CASC.
It added that the changes mean that Chinese cryogenic rockets should be able to stay in orbit for up to 30 days.