  Recent growth in space systems has seen increasing capabilities packed into
smaller and lighter Earth observation and deep space mission spacecraft.
Phase-change materials (PCMs) are nonvolatile, reconfigurable, fast-switching,
and have recently shown a high degree of space radiation tolerance, thereby
making them an attractive materials platform for spaceborne photonics
applications. They promise robust, lightweight, and energy-efficient
reconfigurable optical systems whose functions can be dynamically defined
on-demand and on orbit to deliver enhanced science or mission support in harsh
environments on lean power budgets. This comment aims to discuss the recent
advances in rapidly growing PCM research and its potential to transition from
conventional terrestrial optoelectronics materials platforms to versatile
spaceborne photonic materials platforms for current and next-generation space
and science missions. Materials International Space Station Experiment-14
(MISSE-14) mission-flown PCMs outside of the International Space Station (ISS)
and key results and NASA examples are highlighted to provide strong evidence of
the applicability of spaceborne photonics.
