A large flat panel multifunction display for military and spaceapplications

A flat panel multifunction display (MFD) that offers the size and reliability benefits of liquid crystal display technology while achieving near-CRT display quality is presented. Display generation algorithms that provide exceptional display quality are being implemented in custom VLSI components to minimize MFD size. A high-performance processor converts user-specified display lists to graphics commands used by these components, resulting in high-speed updates of two-dimensional and three-dimensional images. The MFD uses the MIL-STD-1553B data bus for compatibility with virtually all avionics systems. The MFD can generate displays directly from display lists received from the MIL-STD-1553B bus. Complex formats can be stored in the MFD and displayed using parameters from the data bus. The MFD also accepts direct video input and performs special processing on this input to enhance image quality     

Safety testing of lithium ion batteries for navy devices

Lithium ion battery technology is being introduced into power supplies used by our armed forces for a variety of applications. In many cases, the same cells and design parameters that support commercial battery packs are being used in military battery packs. This approach is expected to result in a major decrease in the total life cycle cost of the equipment these batteries support. On June 13, 1991, NAVSEA issued INST9310.1B1, which states that all lithium battery powered equipment must undergo safety evaluation and approval prior to fleet use. This safety program governs a process whereby approvals are issued for lithium batteries to be used in specific equipment on ground facilities, surface combatants, air combatants, and/or submarines. The Naval Ordnance Safety and Security Activity (NOSSA) manages the program. The chief technical advisors are Code 644 at NSWC Carderock Division and Code 609A at NSWC Crane Division. This paper describes three battery designs that incorporate lithium ion technology, and the results of battery safety tests conducted in accordance with navy requirements.     

Commercial technology & avionics architecture

As commercial technology has become more embedded in the military community, there have been attendant effects caused by the rapid progress in technology and by obsolescence. Industry has generated many solutions to mitigate these effects, but their limitations are emerging with time. This is a discussion of higher-level approaches to obsolescence solutions and technology insertion problems that have not hitherto been addressed.     

Analysis of radiation risk from alpha particle component of solar particle events.

The solar particle events (SPE) will contain a primary alpha particle component, representing a possible increase in the potential risk to astronauts during an SPE over the often studied proton component. We discuss the physical interactions of alpha particles important in describing the transport of these particles through spacecraft and body shielding. Models of light ion reactions are presented and their effects on energy and linear energy transfer (LET) spectra in shielding discussed. We present predictions of particle spectra, dose, and dose equivalent in organs of interest for SPE spectra typical of those occurring in recent solar cycles. The large events of solar cycle 19 are found to have substantial increase in biological risk from alpha particles, including a large increase in secondary neutron production from alpha particle breakup.     

An energy management system to improve electric vehicle range andperformance

An electric vehicle (EV) energy management system (EMS) developed to accurately predict and extend the usable driving range and the life of the battery pack is discussed. The EMS monitors and records battery state of charge, vehicle performance, power consumption of key components, and driver's actions. Convenient drive inputs in conjunction with memorized energy consumption profiles allow accurate prediction of driving range and selection of appropriate recharging profiles. EV range extension is accomplished by identifying inefficient use of energy, resulting in EMS modification of energy usage by offending subsystems or EMS suggestion to the driver of improved driving habits or vehicle use. Factors affecting the accuracy of range prediction and the amount of range extension are described     

Critical issues in connection with human missions to Mars: protection of and from the Martian environment.

Human missions to Mars are planned to happen within this century. Activities associated therewith will interact with the environment of Mars in two reciprocal ways: (i) the mission needs to be protected from the natural environmental elements that can be harmful to human health, the equipment or to their operations; (ii) the specific natural environment of Mars should be protected so that it retains its value for scientific and other purposes. The following environmental elements need to be considered in order to protect humans and the equipment on the planetary surface: (i) cosmic ionizing radiation, (ii) solar particle events; (iii) solar ultraviolet radiation; (iv) reduced gravity; (v) thin atmosphere; (vi) extremes in temperatures and their fluctuations; and (vii) surface dust. In order to protect the planetary environment, the requirements for planetary protection as adopted by COSPAR for lander missions need to be revised in view of human presence on the planet. Landers carrying equipment for exobiological investigations require special consideration to reduce contamination by terrestrial microorganisms and organic matter to the greatest feasible extent. Records of human activities on the planet's surface should be maintained in sufficient detail that future scientific experimenters can determine whether environmental modifications have resulted from explorations.     

MEMS Electronically Steerable Antennas for Fire Control Radars

Large apertures are of great benefit to applications that are prime powered limited as is found on aerostat and other airborne platforms. Electronically scanned array antennas are often proposed for these applications. However, increasing the aperture area with conventional array technology is met with prohibitive cost, weight, and prime power increases because of the dense spacing of phase shifters and/or active T/R modules. This discusses the recent development of RF MEMS (Microelectromechanical System) switch technology and the use of these switches in a Radanttrade lens configuration for arrays of approximately 10 m² at X-band. A proof-of-concept 0.4 m² MEMS Electronically Steerable Antenna (ESA) containing 25,000 MEMS switches has been successfully designed, fabricated, and tested. The 0.4 m² MEMS ESA was then integrated with an AN/APG-67 radar system to form the MEMS Demonstration Radar System. The MEMS Demonstration Radar System successfully detected both airborne and ground moving targets during a series of extensive radar demonstrations. This is believed to be the first large scale employment of MEMS switches in a scanning antenna and radar system. The low-cost, lightweight, and low power technology demonstrated can enable weight and power constrained platforms with electronic steering.     

Planetary protection considerations for MarsNet and Mars sample return missions.

The ESA MarsNet mission proposal consists most probably of a trio of Mars landers. These landers each contain a variety of scientific equipment. The network of stations demands for a definition of its planetary protection requirements. With respect to the MarsNet mission only forward contamination problems will be considered. Future involvement of European efforts in planetary exploration including sample returns will also raise the problem of back contamination. A tradeoff study for the overall scientific benefit with respect to the approximative cost is necessary. Planetary protection guide-lines will be proposed by an interdisciplinary and international board of experts working in the fields of both biology and planetary science. These guide-lines will have to be flexible in order to be modified with respect to new research results, e.g. on adaptation of microorganisms to extreme (space) conditions. Experiments on the survival of microorganisms at conditions of simulated Mars surface and subsurface will have to be conducted in order to obtain a baseline data collection as a reference standard for future guide-lines.     

Features of active sidestick controllers

This paper discusses the advantages of incorporating active sidesticks into a modern aircraft cockpit. Active sidestick controllers for manual pilot inputs in pitch and roll are examined for commercial transport aircraft. Options and requirements for sidesticks are reviewed. The recommendation of an active sidestick controller is developed providing both cross-cockpit coupling and autopilot backdrive capability. These characteristics provide pilot cues identical to traditional cable-linked column/yoke configurations     

Multiwavelength monitoring of active galactic nuclei

Recent multiwavelength monitoring of active galactic nuclei (AGN), particularly with the IUE satellite, has produced extraordinary advances in our understanding of the energy-generation mechanism(s) in the central engine and of the structure of the surrounding material. Examples discussed here include both ordinary AGN and blazars (the collective name for highly variable, radio-loud AGN like BL Lac objects and Optically Violently Variable quasars). In the last decade, efforts to obtain single-epoch multiwavelength spectra led to fundamentally new models for the structure of AGN, involving accretion disks for AGN and relativistic jets for blazars. Recent extensions of multiwavelength spectroscopy into the temporal domain have shown that while these general pictures may be correct, the details were probably wrong. Campaigns to monitor Seyfert 1 galaxies like NGC 4151, NGC 5548 and Fairall 9 at infrared, optical, ultraviolet and X-ray wavelengths indicate that broad-emission line regions are stratified by ionization, density, and velocity; argue against a standard thin accretion disk model; and suggest that X-rays represent primary rather than reprocessed radiation. For blazars, years of radio monitoring indicated emission from an inhomogeneous synchrotron-emitting plasma, which could also produce at least some of the shorter-wavelength emission. The recent month-long campaign to observe the BL Lac object PKS 2155-304 has revealed remarkably rapid variability that extends from the infrared through the X-ray with similar amplitude and little or no discernible lag. This lends strong support to relativistic jet models and rules out the proposed accretion disk model for the ultraviolet-X-ray continuum.