Aberration Corrected Echelle Spectrographs for the Far Ultraviolet

Ultraviolet spectroscopy is a key element in the multi-wavelength approach to astronomy. Echelle spectroscopy provides high resolution and broad wavelength coverage and is a frequent choice for optical spectroscopy. However, it has limitations when applied to ultraviolet applications, particularly in the far ultraviolet, at wavelengths shortward of the MgF2 cutoff at similar to 1150 A. I present an approach to provide echelle spectroscopy at these short wavelengths, enabling aberration control with only two optics post-telescope, by using gratings with curved and variable line-space grooves.