Status of Development of a Thermal Probe for Icy Planet Exploration - I

To Support NASA�s future Ocean Worlds Exploration missions, Advanced Cooling Technologies, Inc (ACT) is developing a thermal management concept for a radioisotope-powered ice melting probe. As presented in a previous paper [7], the concept includes several thermal features that allow for an efficient and reliable ice penetration. The development status for three of these features is presented in this paper. These three features are:

1. A pumped two-phase (P2P) loop to collect the waste heat from the cold end of the thermoelectric convertors and deliver it to the front vapor chamber with minimal internal resistance.
2. A front vapor chamber collects the heat from the P2P condenser and spreads the heat uniformly and effectively onto the inner side of the probe�s front for further conduction through the wall and into the environment. The same vapor chamber will deliver heat as needed to the variable conductance sidewall as needed
3. A variable conductance sidewall to prevent refreezing of the probe and also to allow for lateral melting as needed Under SBIR Phase II program, ACT developed detailed analytical models for the aforementioned thermal features. A unique P2P configuration, in which the fluid flow is aligned with the gravity, is modeled and designed. The model is also used to perform a working fluids trade study. A concept for the front vapor chamber is proposed to transfer heat from P2P to the melting head. Thermal calculations are performed for the variable conductance wall to evaluate the effect of heat loss from the side walls of the melting probe.

This work has been performed under NASA Small Business Innovation Research (SBIR) Phase II Contract No. 80NSSC20C0178.