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A 10 KWe dual-mode space power system concept has been identified which is based on INEL's Small Externally-fueled Heat Pipe Thermionic Reactor (SEHPTR) concept. This power system will enhance user capabilities by providing reliable electric power and by providing two propulsion systems; electric power for an arc-jet electric propulsion system and direct thrust by heating hydrogen propellant inside the reactor. The low thrust electric thrusters allow efficient station keeping and long-term maneuvering. The direct thrust capability can provide tens of pounds of thrust at a specific impulse of around 730 seconds for maneuvers that must be performed more rapidly. The direct thrust allows the nuclear power system to move a payload from Low Earth Orbit (LEO) to Geosynchronous Earth Orbit (GEO) in less than one month using approximately half the propellant of a cryogenic chemical stage.

An integration study was performed coupling an SP-100 reactor with either a Brayton or Stirling power conversion subsystem. A power level of 100 kWe was selected for the study. The power system was to be compatible with both the lunar and Mars surface environment and require no site preparation. In addition, the reactor was to have integral shielding and be completely self-contained, including its own auxiliary power for start-up. Initial reliability studies were performed to determine power conversion redundancy and engine module size. Previous studies were used to select the power conversion optimum operating conditions (ratio of hot-side temperature to cold-side temperature). Results of the study indicated that either the Brayton or Stirling power conversion subsystems could be integrated with the SP-100 reactor for either a lunar or Mars surface power application.

This SAE Aerospace Information Report (AIR) describes procedures for use in the field to determine if 115/200 Volt, 400 Hz aircraft external electrical power connectors are excessively worn, which may result in the inability of the external power plug to be retained, intermittent electrical performance and arcing.

This SAE Aerospace Information Report (AIR) describes procedures for use in the field to determine if 115/200 Volt, 400 Hz aircraft external electrical power connectors are excessively worn, which may result in the inability of the external power plug to be retained, intermittent electrical performance and arcing.

Sundstrand is investigating 270-Vdc/hybrid 115-Vac electrical power generating and distribution systems technology so as to be well prepared to offer such systems for future aircraft applications. The approach taken has been to design, build, and test a representative system that meets or exceeds the tightest of the performance standards as defined by miliary standards. This paper describes a single-channel, 120-kW hybrid system and presents some typical performance data. The dc bus supplies a 30-kVA, 400-Hz, 115-Vac inverter; constant power load banks of up to 150 kW; and a resistive load bank of up to 90 kW. System simulation studies indicated the potential for unstable operation due to the negative impedance of the constant power load in conjunction with the source ripple filter and the load EMI filters. Unstable voltage and current were observed in system testing when the magnitude of the source impedance was not sufficiently below that of the load impedance.

Sundstrand has been investigating 270-Vdc/hybrid 115-Vac electrical power generating systems (EPGS) technology in preparation for meeting the electrical power generating system (EPGS) requirements for future aircraft (1). Systems such as the one being investigated are likely to be suitable for the More-Electric Aircraft (MEA) concepts presently under industry and military study. The present Sundstrand single-channel testbed is being further expanded to better understand the electrical system performance characteristics and power quality requirements of an MEA in which traditional mechanical subsystems are replaced by those of a “more-electric” nature. This paper presents the most recent Sundstrand 270-Vdc system transient performance data, and describes the modifications being made to the 270-Vdc/hybrid 115-Vac testbed.

This SAE Aerospace Information Report (AIR) describes field-level procedures to determine if 400 Hz electrical connections for external power may have been subjected to excessive wear, which may result in inadequate disengagement forces.

This SAE Aerospace Information Report (AIR) describes field-level procedures to determine if 400 Hz electrical connections for external power may have been subjected to excessive wear, which may result in inadequate disengagement forces.

The objective of this project was to replace electromechanical power line contactors with a Static Transfer Switch (STS) to improve the transfer of electrical power between aircraft generators and decrease required maintenance. The switch requirements include high reliability, lightweight, and high speed (less than 15mS) power transfer. An STS can shorten the bus transfer time to less than the “ride-through” of aircraft electronic loads and therefore have the ability to control and transfer electrical power while maintaining critical mission requirements. The content of this paper and presentation will discuss the initial problem, the research and development approach, design, and initial testing of the STS.

Vertical-Junction-Field-Effect-Transistors (VJFETs) are currently the most mature SiC devices for high power/temperature switching. High-voltage VJFETs are typically designed normally-on to ensure voltage control operation at high current-gain. However, to exploit the high voltage/temperature capabilities of VJFETs in a normally-off high-current voltage-controlled switch, high-voltage normally-on and low-voltage normally-off VJFETs were connected in the cascode configuration. In this paper, we review the high temperature DC characteristics of VJFETs and 1200 V normally-off cascode switches. The measured parameter shifts in the 25°C to 300°C temperature range are in excellent agreement with theory, confirming fabrication of robust SiC VJFETs and cascode switches.

A 500 hours endurance test was performed with a heavy-duty engine (Euro IV); MAN type D 0836 LFL 51 equipped with a PM-Kat®. As fuel 100% biodiesel was used that met the European specification EN 14214. The 500 hours endurance test included both the European stationary and transient cycle (ESC and ETC) as well as longer stationary phases. During the test, regulated emissions (carbon monoxide, nitrogen oxides, hydrocarbons and particulate matter), the particle number distribution and the aldehydes emission were continuously measured. For comparison, tests with fossil diesel fuel were performed before and after the endurance test. During the endurance test, the engine was failure-free for 500 hours with the biogenic fuel. There were almost no differences in specific fuel consumption during the test, but the average exhaust gas temperature increased by about 15°C over the time. Emissions changed only slightly during the test.

Offering aircraft fuel efficiency improvements of 30 to 40% over the powerplants it will replace, PW2037 retrofit in the 727-200 Advanced and B-52 aircraft is attracting heightened interest. A comparison of PW2037 technical characteristics with current aircraft powerplants substantiates the improvement potential.The engine installation and modifications necessary for aircraft system compatibility do not impose significant increases in complexity or cost. The resultant improvements in aircraft capability (727 and B-52) and economic viability to airlines (7271 produce aircraft uniquely suited to today's operational requirements and constrained equipment budgets.

The 757/767 Flight Management System provides the initial operational implementation of an integrated guidance, control and display equipments based upon digital technology for commercial transport airplanes. The applied equipments are based upon the new ARINC 700 series characteristics developed by the Industry over the past five years. These characteristics were developed on the basis of limited operational experience with selected elements of the system and upon R&D efforts within the Industry. The System features automatic/manual flight profiles for optimum economics, all weather landing including rollout guidance, electronic primary flight instruments based on color (shadow mask) CRTs, inertial attitude/velocity reference based upon laser gyros, improved caution/warning and other improved performance/functional features. The system also provides significant improvements in line and shop maintenance features.

This paper describes the wing and engine ice protection system, used on all 777 aircraft. The 777 ice protection system is unique in two ways: it has an advanced control system which minimizes aircraft power consumption. In addition, the system was procured by the prime contractor, Boeing, as a fully integrated subsystem from a single supplier.

The 912 engine is a well known 4-cylinder horizontally opposed 4-stroke liquid-/air-cooled aircraft engine. The 912 family has a strong track record: 40 000 engines sold / 25 000 still in operation / 5 million flight hours annually. 88% of all light aircraft OEMs use Rotax engines. The 912iS is an evolution of the Rotax 912ULS carbureted engine. The “i” stands for electronic fuel injection which has been developed according to flight standards, providing a better fuel efficiency over the current 912ULS of more than 20% and in a range of 38% to 70% compared to other competitive engines in the light sport, ultra-light aircraft and the general aviation industry. BRP engineers have incorporated several technology enhancements. The fully redundant digital Engine Control Unit (ECU) offers a computer based electronic diagnostic system which makes it easier to diagnose and service the engine.

In the course of CRYOSYSTEM phase B (development phase) financed by the European Space Agency, AIR LIQUIDE (France) and Astrium Space Infrastructure (Germany) have developed an optimized design of a −183°C freezer to be used on board the International Space Station for the freezing and storage of biological samples. The CRYOSYSTEM facility consists of the following main elements: - the CRYORACK, an outfitted standard payload rack (ISPR) accommodating up to three identical Vial Freezers - the Vial Freezer, a dewar vessel capable of fast and ultra-rapid freezing, and storing up to approximately 900 vials below −183°C; the dewar is cooled by a Stirling machine producing > 6 W at 90 K. The Vial Freezer is operational while accommodated in the CRYORACK or attached to the Life Science Glovebox (LSG). One CRYORACK will remain permanently on-orbit for several years while four Vial Freezers and two additional CRYORACKs support the cyclic upload/download of samples.

In low earth orbit satellite applications, spacecraft power is provided by photovoltaic cells and batteries. Unfortunately, use of batteries present difficulties due to their poor energy density, limited cycle lifetimes, reliability problems, and the difficulty in measuring the state of charge. Flywheel energy storage offers a viable alternative to overcome some of the limitations presented by batteries. FARE, Inc. has built a 50 Wh flywheel energy storage system. This system, called the Open Core Flywheel, is intended to be a prototype energy storage device for low earth orbit satellite applications. To date, the Open Core Flywheel has achieved a rotational speed of 26 krpm under digital control.

Some of the methods used for experimental detection and examination of wake vortices are presented. The aim of the article is to provide the reader a brief overview of the available methods. The material is divided into two major sections, one dealing with methods used primarily in the laboratory, and the second part devoted to those used in field operations. Over one hundred articles are cited and briefly discussed.

Europe has embarked on a new programme of space exploration involving the development of rover, lander and probe missions to visit planets, moons and near Earth objects (NEOs) throughout the Solar System. Rovers and landers will require testing under simulated planetary, and NEO conditions to ensure their ability to land on and traverse the alien surfaces. ESA has begun work on a building project that will provide an enclosed and controlled environment for testing rover and lander functions such as landing, mobility, navigation and soil sampling. The facility will first support the European ExoMars mission due for launch in 2013. This mission will deliver a robotic rover to the Martian surface. This paper, the first of several on the project, gives an overview of its design configuration and construction phasing. Future papers will cover its applications and operations.