The Double Asteroid Redirection Test (DART) is a spacecraft that will impact the smaller body of the binary asteroid Didymos. As a technology demonstration, this will be the first time a kinetic impactor is used to perturb the motion of a near earth object. This technique could someday be used to deflect a dangerous asteroid on a future collision course with Earth. As the only instrument aboard DART, the Didymos Reconnaissance and Asteroid Camera for OpNav (DRACO) serves two purposes. First, DRACO provides images to the Small-body Maneuvering Autonomous Real-Time Navigation (SMARTNav) algorithm, allowing the spacecraft to precisely locate and impact the target. In its final moments, DRACO will also characterize the impact site by providing high resolution, scientific imagery of the surface. Derived from the Long Range Reconnaissance Imager (LORRI) on New Horizons, the telescope is a 208 mm aperture, f/12.6, catadioptric Ritchey-Chrétien, with a 0.29 degree field of view. A lightweight opto-mechanical structure, with low CTE mirror substrates and a composite baffle tube, maintains telescope focus in the low temperature environment of deep space. At the focal plane is a 2560 by 2160 pixel, panchromatic, front-side illuminated complementary metal oxide semiconductor (CMOS) image sensor, with digital output, global shutter, and low read noise. A highly integrated focal plane electronics (FPE) module controls the sensor and relays data to the spacecraft.
SSUSI-Lite is an update of an existing sensor, SSUSI. The current generation of Defense Meteorological Satellite Program (DMSP) satellites (Block 5D3) includes a hyperspectral, cross-tracking imaging spectrograph known as the Special Sensor Ultraviolet Spectrographic Imager (SSUSI). SSUSI has been part of the DMSP program since 1990. SSUSI is designed to provide space weather information such as: auroral imagery, ionospheric electron density profiles, and neutral density composition changes. The sensors that are flying today (see http://ssusi.jhuapl.edu) were designed in 1990 - 1992. There have been some significant improvements in flight hardware since then. The SSUSI-Lite instrument is more capable than SSUSI yet consumes ½ the power and is ½ the mass. The total package count (and as a consequence, integration cost and difficulty) was reduced from 7 to 2. The scan mechanism was redesigned and tested and is a factor of 10 better. SSUSI-Lite can be flown as a hosted payload or a rideshare – it only needs about 10 watts and weighs under 10 kg. We will show results from tests of an interesting intensified position sensitive anode pulse counting detector system. We use this approach because the SSUSI sensor operates in the far ultraviolet – from about 110 to 180 nm or 0.11 to 0.18 microns.