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The SPEAR (or 'FIMS') instrumentation has been used to conduct the first large-scale spectral mapping of diffuse cosmic far ultraviolet (FUV, 900-1750 AA) emission, including important diagnostics of interstellar hot (10^4 K - 10^6 K) and photoionized plasmas, H_2, and dust scattered starlight. The instrumentation's performance has allowed for the unprecedented detection of astrophysical diffuse far UV emission lines. A spectral resolution of 550 and an imaging resolution of 5' is achieved on-orbit in the Short (900 - 1175 AA) and Long (1335 - 1750 AA) bandpass channels within their respective 7.4 deg x 4.3' and 4.0 deg x 4.6' fields of view. We describe the SPEAR imaging spectrographs, their performance, and the nature and handling of their data

A system of 5020 robotic fiber positioners was installed in 2019 on the Mayall Telescope, at Kitt Peak National Observatory. The robots automatically retarget their optical fibers every 10–20 minutes, each to a precision of several microns, with a reconfiguration time of fewer than 2 minutes. Over the next 5 yr, they will enable the newly constructed Dark Energy Spectroscopic Instrument (DESI) to measure the spectra of 35 million galaxies and quasars. DESI will produce the largest 3D map of the universe to date and measure the expansion history of the cosmos. In addition to the 5020 robotic positioners and optical fibers, DESI’s Focal Plane System includes six guide cameras, four wave front cameras, 123 fiducial point sources, and a metrology camera mounted at the primary mirror. The system also includes associated structural, thermal, and electrical systems. In all, it contains over 675,000 individual parts. We discuss the design, construction, quality control, and integration of all these components. We include a summary of the key requirements, the review and acceptance process, on-sky validations of requirements, and lessons learned for future multiobject, fiber-fed spectrographs.

Abstract-Thick, fully depleted p-channel charge-coupled devices (CCDs) have been developed at the Lawrence Berkeley National Laboratory (LBNL). These CCDs have several advantages over conventional thin, n-channel CCDs, including enhanced quantum efficiency and reduced fringing at nearinfrared wavelengths and improved radiation tolerance. Here we report results from the irradiation of CCDs with 12.5 and 55 MeV protons at the LBNL 88-Inch Cyclotron and with 0.1 -1 MeV electrons at the LBNL 60 Co source. These studies indicate that the LBNL CCDs perform well after irradiation, even in the parameters in which significant degradation is observed in other CCDs: charge transfer efficiency, dark current, and isolated hot pixels. Modeling the radiation exposure over a sixyear mission lifetime with no annealing, we expect an increase in dark current of 20 e − /pixel/hr, and a degradation of charge transfer efficiency in the parallel direction of 3 × 10 −6 and 1 × 10 −6 in the serial direction. The dark current is observed to improve with an annealing cycle, while the parallel CTE is relatively unaffected and the serial CTE is somewhat degraded. As expected, the radiation tolerance of the p-channel LBNL CCDs is significantly improved over the conventional n-channel CCDs that are currently employed in space-based telescopes such as the Hubble Space Telescope.