The SSULI (Special Sensor Ultraviolet Limb Imager) is a low-resolution hyperspectral far- and extreme-ultraviolet limb-scanning imager designed to monitor ionospheric and thermospheric airglow. SSULI has a spectral range from 80 to 170 nm, and a nominal resolution of 2.1 nm (at 147 nm). The instrument is scheduled to fly aboard all DMSP Block 5D3 weather satellites. The first SSULI instrument was launched in fall 2003, aboard DMSP F16, and has been collecting data since December 2003. The second SSULI flight aboard DMSP F17 began in fall 2006. On the ground, the SSULI instruments are calibrated using a monochromator to isolate single emission features of interest produced by a gas discharge lamp, whereas the flight spectra consists of numerous overlapping emissions. The determination of individual emission feature contribution against the entire airglow spectrum is determined using the multiple linear regression technique with basis functions defining each observable emission. The accuracy of the emission extraction depends primarily on the ability to model the characteristics of the instrument line-shape, encompassing both optical and electronic effects. In the course of developing the ground calibration algorithms, we are now able to produce line-shapes much more faithful to the observed calibration features, as well as model instrument characteristics such as scattered light and detector background components. This improved instrument characterization can then be passed to the operational orbital emission extraction software to increase the fidelity of retrieved altitude profiles for observed ultraviolet emissions. In addition, the techniques used with the ground calibration can monitor deviations in line-shape and instrument sensitivity as a function of observed count rate, and these modified line-shapes can also be passed to the ground analysis software. Validation of this method using SSULI 003 and 004 ground calibration data will be presented.

The Atmospheric Neutral Density Experiment Risk Reduction (ANDERR) flight is a mission proposed by the Naval Research Laboratory to monitor the thermospheric neutral density at an altitude of 400km. The primary mission objective is to test the deployment mechanism from the Space Shuttle for the ANDE flight in 2008. Scientific objectives of the ANDE risk reduction flight include; monitor total neutral density along the orbit for improved orbit determination of resident space objects, monitor the spin rate and orientation of the spacecraft, provide a test object for polarimetry studies using the HI-CLASS system. The mission consists of two spherical spacecraft fitted with retro-reflectors for satellite laser ranging (SLR). Each spacecraft contains a small light-weight payload designed to determine the spin rate and orientation of the spacecraft from on-orbit measurements and from ground based observations. A unique design requirement of one satellite is to telemeter the data to the ground without external protrusions from the spherical spacecraft (i.e. an antenna). This satellite will carry a communications system developed by the USNA that uses two aluminum hemispheres as the ends of a dipole antenna, at amateur radio frequencies. This system will act as a backup communications platform in the full ANDE mission, planned for 2008. The techniques for determining spin rate and orientation of the satellite include: an orthogonal array of photovoltaic cells, an orthogonal array of laser diodes (to be observed by the HI-CLASS sensors at the Air Force Maui Space Surveillance Site), and variations in the light reflected by the ANDE sphere, which will have a specific pattern of different surface finishes. This paper presents a mission overview and emphasis will be placed on the design, optical layout, performance, ground station, ground truth, and science capabilities of the mission. The ANDE flights are integrated and managed under the direction of the Department of Defense (DoD) Space Test Program (STP), Human Spaceflight Payloads Office, at NASA's Johnson Space Center.

The first of five Special Sensor Ultraviolet Limb Imager (SSULI) sensors was launched on the Defense Meteorological Satellite Program (DMSP) F16 spacecraft in October of 2003 into a sun-synchronous 830 km circular orbit at a local time of 0800-2000 UT. During initial sensor turn-on and evaluation, unusually high levels of background events were observed by the detector. The severity of this background is often sufficient to exceed the counting limit of the electronics as well as contribute to a rapid decrease in detector performance. In light of the SSULI performance degradation and concerns that the subsequent sensors may be affected in a similar manner, a "Tiger Team" investigation was launched to determine the source of the anomalous events. The conclusion from the investigation attributes the observed anomalous events to high levels of non-photon noise caused by ambient ions entering the instrument and striking the front microchannel plate. Additionally, the team made recommendations to mitigate the problem on future flights.

The Low Resolution Airglow & Aurora Spectrograph (LORAAS) was an aeronomy Instrument designed by the Naval Research Laboratory (NRL). LORAAS was launched into polar orbit on February 23, 1999 aboard the ARGOS spacecraft and operated successfully until the shutdown of the spacecraft in April of 2002. Data gained from the on-orbit performance of the LORAAS mechanisms will be presented along with the performance data taken during ground testing. There were three mechanisms used in LORASS design and are as follows; a guillotine style dust cover door assembly (DCDA), a one-axis scan mirror assembly (SMA), and a detector door mechanism (DDM). These mechanisms are unique in that they must all adhere to the stringent requirements of contamination control due to the sensitivity of the optics used. In addition to supporting instrument operation while in space, some of these mechanisms, such as the DDM and DCDA, were essential for instrument operation while on the ground to aid in instrument construction, calibration and storage. This paper will present a description of the aforementioned mechanisms including an overview of the requirements driving their design, analysis performed on the mechanisms and their components, and final costs.