ALBERT

Description: The art of flight quality solid-state laser development is still relatively young, and much is still unknown regarding the best procedures, components, and packaging required for achieving the maximum possible lifetime and reliability when deployed in the harsh space environment. One of the most important issues is the limited and unstable supply of quality, high power diode arrays with significant technological heritage and market lifetime. Since Spectra Diode Labs Inc. ended their involvement in the pulsed array business in the late 199O's, there has been a flurry of activity from other manufacturers, but little effort focused on flight quality production. This forces NASA, inevitably, to examine the use of commercial parts to enable space flight laser designs. System-level issues such as power cycling, operational derating, duty cycle, and contamination risks to other laser components are some of the more significant unknown, if unquantifiable, parameters that directly effect transmitter reliability. Designs and processes can be formulated for the system and the components (including thorough modeling) to mitigate risk based on the known failures modes as well as lessons learned that GSFC has collected over the past ten years of space flight operation of lasers. In addition, knowledge of the potential failure modes related to the system and the components themselves can allow the qualification testing to be done in an efficient yet, effective manner. Careful test plan development coupled with physics of failure knowledge will enable cost effect qualification of commercial technology. Presented here will be lessons learned from space flight experience, brief synopsis of known potential failure modes, mitigation techniques, and options for testing from the system level to the component level.

Description: The MESSENGER mission to Mercury offers our first opportunity to explore this planet s miniature magnetosphere since the brief flybys of Mariner 10. Mercury s magnetosphere is unique in many respects. The magnetosphere of Mercury is among the smallest in the solar system; its magnetic field typically stands off the solar wind only - 1000 to 2000 km above the surface. For this reason there are no closed drift paths for energetic particles and, hence, no radiation belts. The characteristic time scales for wave propagation and convective transport are short and kinetic and fluid modes may be coupled. Magnetic reconnection at the dayside magnetopause may erode the subsolar magnetosphere allowing solar wind ions to impact directly the regolith. Inductive currents in Mercury s interior may act to modify the solar wind interaction by resisting changes due to solar wind pressure variations. Indeed, observations of these induction effects may be an important source of information on the state of Mercury s interior. In addition, Mercury s magnetosphere is the only one with its defining magnetic flux tubes rooted in a planetary regolith as opposed to an atmosphere with a conductive ionospheric layer. This lack of an ionosphere is probably the underlying reason for the brevity of the very intense, but short-lived, - 1-2 min, substorm-like energetic particle events observed by Mariner 10 during its first traversal of Mercury s magnetic tail. Because of Mercury s proximity to the sun, 0.3 - 0.5 AU, this magnetosphere experiences the most extreme driving forces in the solar system. All of these factors are expected to produce complicated interactions involving the exchange and re-cycling of neutrals and ions between the solar wind, magnetosphere, and regolith. The electrodynamics of Mercury s magnetosphere are expected to be equally complex, with strong forcing by the solar wind, magnetic reconnection at the magnetopause and in the tail, and the pick-up of planetary ions all driving field-aligned electric currents. However, these field-aligned currents do not close in an ionosphere, but in some other manner. In addition to the insights- into magnetospheric physics offered by study of the solar wind - Mercury system, quantitative specification of the "external" magnetic field generated by magnetospheric currents is necessary for accurate determination of the strength and multi-polar decomposition of Mercury s intrinsic magnetic field. MESSENGER S highly capable instrumentation and broad orbital coverage will greatly advance our understanding of both the origin of Mercury s magnetic field and the acceleration of charged particles in small magnetospheres. In. this article, we review what is known about Mercury s magnetosphere and describe the MESSENGER science team s strategy for obtaining answers to the outstanding science questions surrounding the interaction of the solar wind with Mercury and its small, but dynamic, magnetosphere.

Description: A solid-state, side pumping scheme, designed to enhance pump energy absorption, has been adapted for use in small, side-pumped, Nd+3:YAG zigzag lasers. This technique allows for pump radiation to make four complete passes through the gain medium, effectively doubling the absorption length of the usual 2-pass geometry. This produces higher inversion densities, higher gains, broader operating temperature bands and overall higher efficiencies. The improved performance has been demonstrated with a small Nd+3:YAG, mJ-class oscillator, and will aid in the development for space-based remote sensing laser transmitters for altimetry and mapping instruments.

Description: Engine external components include all the fluid carrying, electron carrying, and support devices that are needed to operate the propulsion system. These components are varied and include: pumps, valves, actuators, solenoids, sensors, switches, heat exchangers, electrical generators, electrical harnesses, tubes, ducts, clamps and brackets. The failure of any component to perform its intended function will result in a maintenance action, a dispatch delay, or an engine in flight shutdown. The life of each component, in addition to its basic functional design, is closely tied to its thermal and dynamic environment .Therefore, to reach a mature design life, the component's thermal and dynamic environment must be understood and controlled, which can only be accomplished by attention to design analysis and testing. The purpose of this paper is to review analysis and test techniques toward achieving good component health.

Description: This slide presentation reviews the Functional Task Test (FTT), an interdisciplinary testing regimen that has been developed to evaluate astronaut postflight functional performance and related physiological changes. The objectives of the project are: (1) to develop a set of functional tasks that represent critical mission tasks for the Constellation Program, (2) determine the ability to perform these tasks after space flight, (3) Identify the key physiological factors that contribute to functional decrements and (4) Use this information to develop targeted countermeasures.

Description: This presentation provides an overview of the Living With a Star (LWS) Radiation Belt Storm Probes (RBSP) mission in the context of the broader Geospace program. Missions to Geospace offer an opportunity to observe in situ the fundamental processes that operate throughout the solar system and in particular those that generate hazardous space weather effects in the vicinity of Earth. The recently selected investigations on NASA's LWS program's RBSP will provide the measurements needed to characterize and quantify the processes that supply and remove energetic particles from the Earth's Van Allen radiation belts. Instruments on the RBSP spacecraft will observe charged particles that comprise the Earth's radiation belts over the full energy range from 1 eV to more than 10 MeV (including composition), the plasma waves which energize them, the electric fields which transport them, and the magnetic fields which guide their motion. The two-point measurements by the RBSP spacecraft will enable researchers to discriminate between spatial and temporal effects, and therefore between the various proposed mechanisms for particle acceleration and loss. The measurements taken by the RBSP spacecraft will be used in data modeling projects in order to improve the understanding of these fundamental processes and allow better predictions to be made. NASA's LWS program has also recently selected three teams to study concepts for Missions of Opportunity that will augment the RBSP program, by (1) providing an instrument for a Canadian spacecraft in the Earth's radiation belts, (2) quantifying the flux of particles precipitating into the Earth's atmosphere from the Earth's radiation belts, and (3) remotely sensing both spatial and temporal variations in the Earth's ionosphere and thermosphere.

Description: As the first of the new Mars Scouts missions, the Phoenix project was selected by NASA in August of 2003. Four years later, almost to the day, Phoenix was launched from Cape Canaveral Air Station and successfully injected into an interplanetary trajectory on its way to Mars. On May 25, 2008 Phoenix conducted the first successful powered decent on Mars in over 30 years. This paper will highlight some of the key changes since the 2008 IEEE paper of the same name, as well as performance through cruise, landing at the north pole of Mars and some of the preliminary results of the surface mission.

Description: Aerocoat AR-7 is a coating that has been used to protect stainless steel flex hoses at NASA's Kennedy Space Center launch complex and hydraulic lines of the mobile launch platform (MLP). This coating has great corrosion control performance and low temperature application. AR-7 was developed by NASA and produced exclusively for NASA but its production has been discontinued due to its high content of volatile organic compounds (VOC) and significant environmental impact. The purpose of this project was to select and evaluate candidate coatings to find a replacement coating that is more environmentally friendly, with similar properties to AR-7. No coatings were identified that perform the same as AR-7 in all areas. Candidate coatings failed in comparison to AR-7 in salt fog, beachside atmospheric exposure, pencil hardness, Mandrel bend, chemical compatibility, adhesion, and ease of application tests. However, two coatings were selected for further evaluation.

Description: A document presents an updated discussion on a method of autonomous navigation for a robotic vehicle navigating across rough terrain. The method involves, among other things, the use of a measure of traversability, denoted the fuzzy traversability index, which embodies the information about the slope and roughness of terrain obtained from analysis of images acquired by cameras mounted on the robot. The improvements presented in the report focus on the use of the fuzzy traversability index to generate a traversability map and a grid map for planning the safest path for the robot. Once grid traversability values have been computed, they are utilized for rejecting unsafe path segments and for computing a traversalcost function for ranking candidate paths, selected by a search algorithm, from a specified initial position to a specified final position. The output of the algorithm is a set of waypoints designating a path having a minimal-traversal cost.