The SLICE, CHESS, and SISTINE Ultraviolet Spectrographs: Rocket-Borne Instrumentation Supporting Future Astrophysics Missions

Abstract

Received (to be inserted by publisher); Revised (to be inserted by publisher); Accepted (to be inserted by publisher); NASA's suborbital program provides an opportunity to conduct unique science experiments above Earth's atmosphere and is a pipeline for the technology and personnel essential to future space astrophysics, heliophysics, and atmospheric science missions. In this paper, we describe three astronomy payloads developed (or in development) by the Ultraviolet Rocket Group at the University of Colorado. These far-ultraviolet (100 -160 nm) spectrographic instruments are used to study a range of scientific topics, from gas in the interstellar medium (accessing diagnostics of material spanning five orders of magnitude in temperature in a single observation) to the energetic radiation environment of nearby exoplanetary systems. The three instruments, SLICE (Suborbital Local Interstellar Cloud Experiment), CHESS (Colorado High-resolution Echelle Stellar Spectrograph), and SISTINE (Suborbital Imaging Spectrograph for Transition region Irradiance from Nearby Exoplanet host stars) form a progression of instrument designs and component-level technology maturation. SLICE is a pathfinder instrument for the development of new data handling, storage, and telemetry techniques. CHESS and SISTINE are testbeds for technology and instrument design enabling high-resolution (R > 10 5 ) point source spectroscopy and high throughput imaging spectroscopy, respectively, in support of future Explorer, Probe, and Flagship-class missions. The CHESS and SISTINE payloads support the development and flight testing of large-format photon-counting detectors and advanced optical coatings: NASA's top two technology priorities for enabling a future flagship observatory (e.g., the LUVOIR Surveyor concept) that offers factors of ~50 -100 gain in ultraviolet spectroscopy capability over the Hubble Space Telescope. We present the design, component level laboratory characterization, and flight results for these instruments.

Atomic Layer Deposition of Lithium Fluoride Optical Coatings for the Ultraviolet

“…In this case, loss in the protective coating dominates the short wavelength reflectance of the mirror; MgF 2 /Al can typically provide meaningful reflectance (R > 50%) down to~115 nm, AlF 3 /Al down to~110 nm, and LiF/Al down to~100 nm. This has motivated the use of LiF/Al mirrors on optical telescope systems in space applications when the desired scientific observations require this FUV throughput [6,7].…”

The fourth flight of CHESS: spectral resolution enhancements for high-resolution FUV spectroscopy

“…The highresolution instrument was designed to achieve resolving powers ≥ 100,000 λ/∆λ across a bandpass of 1000−1600 A. 5 The operating principle of the instrument is as follows:…”

Mapping the low-surface brightness Universe in the UV band with Lyα emission from IGM filaments

“…The Faint Intergalactic Redshifted Emission Ballon (FIREBall2) is able to measure Lyα , OVI and CIV emission from the WHIM at 205 nm (Tuttle et al 2010), and its sucessor, the proposed Imaging Space Telescope for Origins Survey (ISTOS) plans on targeting Lyα emission from z ∼ 0.5 − 1.2. There are also several orbital sounding rockets carrying integral field spectrometers able to detect Lyα emission from galaxies and from the CGM in the redshift range (z ∼ 0 − 1.5) (France et al 2015). The Cosmic Origins Spectrograph (COS) on board of the Hubble Space Telescope also targets Lyα emission from galaxies and from the CGM in the redshift range (z ∼ 0 − 1.5) (Morse et al 1998;Green et al 2003).…”