The Venera probes used this idea in the 1970s. [0] > One new idea, for additional thermal protection, was the addition of phase-change material. Lithium nitrat

The Venera probes used this idea in the 1970s. [0] > One new idea, for additional thermal protection, was the addition of phase-change material. Lithium nitrate trihydrate melts at 30° C, absorbing a large amount of heat, due to its high latent heat of fusion. [0] http://mentallandscape.com/V_Lavochkin1.htm http://mentallandscape.com/V_Lavochkin1.htm