NIAC ("NASA Innovative Advanced Concepts") has approved the following research application for 2015 funding:
Cryogenic Selective Surfaces
Robert Youngquist (NASA Kennedy Space Center)
Selective surfaces have wavelength dependent emissivity/absorption. These surfaces can be designed to reflect solar radiation, while maximizing infrared emittance, yielding a cooling effect even in sunlight. On earth cooling to -50 °C below ambient has been achieved, but in space, outside of the atmosphere, theory using ideal materials has predicted a maximum cooling to 40 K! If this result holds up for real world materials and conditions, then superconducting systems and cryogenic storage can be achieved in space without active cooling. Such a result would enable long term cryogenic storage in deep space and the use of large scale superconducting systems for such applications as galactic cosmic radiation (GCR) shielding and large scale energy storage. We propose, during this Phase I effort, to theoretically model the performance of real world selective surfaces to see if superconducting temperatures can be passively achieved in a deep space environment at 1 A.U. from the sun.
A quick search gave me a sample material from Solec designed for the exactly opposite scenario.
What are the candidate selective surface coatings (low on solar spectrum absorptivity, high on IR emissivity)?
What are their technology readiness levels*?
Have any coatings been tested in vacuum for outgassing and its impact on performance?
* A white paper describing NASA TRLs (pdf)