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As we build towards robustly detecting and characterizing the atmospheres of terrestrial exoplanets with JWST comma we cannot forget to take a close look at the low-mass stars they orbit. Complete coverage of M dwarf ultraviolet spectra are needed to determine the photochemical production rates of molecular species in terrestrial planet atmospheres comma which will alert us to when disequilibrium chemistry comma a sign of surface processes or even life comma is present. High-energy spectra from the UV to X-ray are also needed to calculate mass loss rates from planetary atmospheres comma which can explain the lack of atmospheres around highly-irradiated terrestrial worlds. LTT 1445Ab and GJ 486b are two of the most spectroscopically accessible terrestrial exoplanets we will ever find comma and their M dwarf hosts are similarly at the top of their class in terms of observability. We will use the unique ultraviolet capabilities of HST comma supplemented by X-ray observations comma to provide complete short-wavelength spectral coverage for the stars LTT 1445A and GJ 486. Both planets comma LTT 1445Ab and GJ 486b comma will be observed in JWST Cycle 1 with the aim of detecting their atmospheres. If we do not take the opportunity to make UV measurements of their host stars while HST is still operational comma this crucial input to understanding the atmospheres of these planets will be lost. We request 18 orbits with HST (COS and STIS) to capture complete UV spectra of LTT 1445A and GJ 486.