Loop Heat Pipe Laser Diode Array Cooling System

Two-phase loops have significant flight heritage having demonstrated high reliability and long life in the space environment. However, a shortfall of existing aerospace-grade two-phase loops is their relatively low heat flux capacity in the range of tens of watts/cm2. This program applies a new evaporator design to cooling of laser diode arrays on space platforms. The new evaporator design will enable heat flux > 700 W/cm2 in a small, lightweight package. The Phase I work demonstrated that heat fluxes over 1,000 W/cm2 are viable with this evaporator in a loop heat pipe or hybrid loop heat pipe architecture. The Phase II effort will fabricate and test various configurations of the evaporator design to optimize heat flux limit and evaporator conductance. In Year 2 the evaporator design will include integraton of VCSEL diode arrays to the evaporator surface and optical testing of the lasers. In the Option Period a flight typical hybrid loop heat pipe will be fabricated using the new laser evaporator module and tested.