Microvascular Composite Radiators for Small Spacecraft Thermal Management Systems

Small spacecraft have typically relied on thermal control systems in which waste heat is conducted through structural elements to the surface where it is radiated away. This simplistic approach is adequate for low-complexity missions at low Earth orbit (LEO), but increasingly complex mission profiles are being proposed, including missions to deep space locations which present a harsher thermal environment. In addition, small satellites are incorporating increasingly advanced capabilities which have challenging thermal control requirements such as cryogenically cooled sensors or propulsion systems. The University of Illinois at Urbana-Champaign, in partnership with NASA Ames Research Center, is developing a thermal control system for small spacecraft. This thermal control system utilizes a deployable radiator made of a micro-vascular composite material through which a coolant can be circulated. These microvascular composite radiators contain tiny channels that can be as small as 100 micrometers in diameter. These channels can only be manufactured using a novel fabrication technique developed at the University of Illinois, the Vaporization of Sacrificial Components (VaSC). Preliminary thermal simulation as well as vacuum leak tests were evaluated to determine the design guidelines for the cooling system. Moving forward, thermal vacuum testing of the prototype will raise the TRL to 6 by the end of the two-year development program.