[1] The long-term stability of exoplanetary atmospheres depends critically on the extreme-ultraviolet (EUV) flux from the host star.

ESCAPE is an astrophysics Small Explorer proposed to NASA that employs extreme- and far-ultraviolet spectroscopy (80 – 1650 Å) to characterize the high-energy radiation environment in the habitable zones (HZs) around nearby stars.

ESCAPE provides the first comprehensive study of the stellar EUV environments that control atmospheric mass-loss and determine the habitability of rocky exoplanets.

2) A deep monitoring survey (~2 weeks per star) of 24 targets-of-interest to measure the stellar flare frequency distribution and constrain the coronal mass ejection (CME) rate and high-energy particle fluence from these objects.

Together, these surveys provide the crucial stellar drivers that regulate habitable environments on planets targeted by upcoming atmospheric characterization missions, from James Webb Space Telescope to Large Ultraviolet Optical Infrared Surveyor.