ESCAPE: a small explorer mission to study the stellar drivers of exoplanet evolution
Allison Youngblood, Kevin France, Brian Fleming, Tim H. Hellickson, Alan C. Hoskins, James Paul Mason, Dolon Bhattacharyya, Hannah Diamond-Lowe, Girish M. Duvvuri, Cynthia S. Froning, Vinay L. Kashyap, Tommi T. Koskinen, Yuta Notsu, Seth Redfield, David J. Wilson, Ute V. Amerstorfer, Tracy M. Becker, Francesco Borsa, David A. Brain, Luca Fossati, Briana Indahl, Meng Jin, Graham S. Kerr, Adam F. Kowalski, Rachel A. Osten, Tom L. Patton, Steven V. Penton, Ignazio Francesco Pillitteri, Kurt D. Retherford, Astrid M. Veronig, Aline A. Vidotto, Jennifer G. Winters, Adina D. Feinstein, Guillaume P. Gronoff, Jeffrey L. Linsky, R. O. Parke Loyd, Susan E. Mullally, Jorge Sanz-Forcada, Peter J. Wheatley, Amber V. Young
astro-ph.EP, astro-ph.IM, astro-ph.SR
Submitted: 2026-08-01
License: http://creativecommons.org/licenses/by/4.0/
The gist: The long-term stability of exoplanetary atmospheres depends critically on the extreme-ultraviolet (EUV) photon and high-energy particle fluxes from the host star, which are poorly constrained.
Terminology
Abstract
The long-term stability of exoplanetary atmospheres depends critically on the extreme-ultraviolet (EUV) photon and high-energy particle fluxes from the host star, which are poorly constrained. To address this key gap in our understanding of atmospheric retention, we present the Extreme-ultraviolet Stellar Characterization for Atmospheric Physics and Evolution (ESCAPE) mission, a NASA Small Explorer concept proposed in 2026. ESCAPE employs extreme- and far-ultraviolet spectroscopy (80 - 1650 Ang) to provide the first comprehensive study of the stellar EUV history and stellar coronal mass ejection (CME) environments that control atmospheric mass-loss and determine the habitability of rocky exoplanets. This paper outlines both the primary science goals of the mission, the breadth of future general observer investigations, and a detailed design study of the mission's instrumentation. The ESCAPE instrument comprises a grazing incidence telescope that feeds multiple diffraction gratings and a photon-counting detector. We describe a demonstration of the Hettrick-Bowyer telescope, etched silicon diffraction gratings, the microchannel plate detector and housing, and gold and zirconium coatings. We present a STOP analysis that verifies ESCAPE's ability to meet its structural integrity, thermal stability, and optical performance requirements throughout the mission environment.
Sources
- Science with the Ultraviolet Explorer (UVEX)
- NASA Exoplanet Exploration Program (ExEP) Mission Star List for the Habitable Worlds Observatory (2023)
- exoatlas: friendly Python code for exoplanet populations
- Evidence for an Atmosphere on the Ultra-Short Period super-Earth HD 3167 b
- Report of the Working Group on Strategic Exoplanet Initiatives with HST and JWST
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