Refine Your Search

Topic

Author

Search Results

Technical Paper

Nitrogen Oxygen Recharge System (NORS) for the International Space Station

2009-07-12
2009-01-2413
The International Space Station (ISS) requires stores of Oxygen (O2) and Nitrogen (N2) to provide for atmosphere replenishment, direct crew member usage, and payload operations. Currently, supplies of N2/O2 are maintained by transfer from the Space Shuttle. Following Space Shuttle retirement in 2010, an alternate means of resupplying N2/O2 to the ISS is needed. The National Aeronautics and Space Administration (NASA) has determined that the optimal method of supplying the ISS with O2/N2 is using tanks of high pressure N2/O2 carried to the station by a cargo vehicle capable of docking with the ISS. This paper will outline the architecture of the system selected by NASA and will discuss some of the design challenges associated with this use of high pressure oxygen and nitrogen storage in the human spaceflight environment.
Technical Paper

Calculations of Ice Shapes on Oscillating Airfoils

2011-06-13
2011-38-0015
The desire to operate rotorcraft in icing conditions has renewed the interest in developing high-fidelity analysis methods to predict ice accumulation and the ensuing rotor performance degradation. A subset of providing solutions for rotorcraft icing problems is predicting two-dimensional ice accumulation on rotor airfoils. While much has been done to predict ice for fixed-wing airfoil sections, the rotorcraft problem has two additional challenges: first, rotor airfoils tend to experience flows in higher Mach number regimes, often creating glaze ice which is harder to predict; second, rotor airfoils oscillate in pitch to produce balance across the rotor disk. A methodology and validation test cases are presented to solve the rotor airfoil problem as an important step to solving the larger rotorcraft icing problem. The process couples Navier-Stokes CFD analysis with the ice accretion analysis code, LEWICE3D.
Journal Article

Disturbance of Electronics in Low-Earth Orbits by High Energy Electron Plasmas

2009-07-12
2009-01-2339
Electrical disturbances caused by charging of cables in spacecraft can impair electrical systems for long periods of time. The charging originates primarily from electrons trapped in the radiation belts of the earth. The model Space Electrons Electromagnetic Effects (SEEE) is applied in computing the transient charge and electric fields in cables on spacecraft at low to middle earth altitudes. The analysis indicated that fields exceeding dielectric breakdown strengths of common dielectric materials are possible in intense magnetic storms for systems with inadequate shielding. SEEE also computes the minimal shielding needed to keep the electric fields below that for dielectric breakdown.
Journal Article

Self-Configuring Hybrid Duct System and Attachment Technologies for Environmental Control Systems

2009-11-10
2009-01-3277
Environmental Control Systems (ECS) ducts on airplanes are primarily fabricated from aluminum or thermoset composites, depending on temperature and pressure requirements. It is imperative to fabricate lightweight, cost effective, durable, and repairable systems with minimal tooling. It is also important that the duct systems are easy to assemble even with alignment issues resulting from structural variations, tolerance accumulation, variation from thermal expansion of different materials, and inherent duct stiffness. These requirements create an opportunity and need for a technology that can address all of these issues, while increasing performance at the same time. This report provides a background on current ECS ducting systems.
Journal Article

Role of Power Distribution System Tests in Final Assembly of a Military Derivative Airplane

2009-11-10
2009-01-3121
Boeing has contracts for military application of twin engine airplanes generically identified in this paper as the MX airplane. Unlike previous derivatives, the MX airplanes are produced with a streamlined manufacturing process to improve cost and schedule performance. The final assembly of each MX airplane includes a series of integration tests, called factory functional tests (FFTs), which are modified from those of typical commercial versions and verify correctness of equipment installation and basic functionalities. Two airplanes have been through the production line resulting in a number of FFT lessons learned. Addressed are the power distribution lessons learned: 1) the expanded coverage of the basic automated power-on generation system test, 2) the need for a manual wire continuity test, 3) salient features of the power distribution tests, and 4) keys to make first pass power distribution test smooth and successful.
Technical Paper

THE EVOLUTIONARY DEVELOPMENT AND CURRENT STATUS OF THE AUGMENTOR WING CONCEPT

1970-02-01
700812
A review is made of previously reported status of the augmentor wing concept, including test work of de Havilland Aircraft of Canada and the NASA Ames Research Center. More recent NASA data which formed the basis for proceeding with a flight research vehicle program on the Buffalo CV-7A are discussed. This background is used to show potential application to a turbofan-powered production airplane concept whose highly integrated propulsion and aerodynamics show promise for a very quiet STOL. Proposed future augmentor wing development programs are also briefly discussed.
Technical Paper

Liquid Water Content and Droplet Size Distribution Mass Fractions for Wind Milling Engine Fan Blade Ice Accretion Analysis

2007-09-24
2007-01-3291
A procedure for calculating the engine inlet diffuser section liquid water content and mass fractions of liquid water content associated with the water droplet size distribution for wind milling engine ice accretion analysis is presented. Critical fuel reserve calculation for extended twin-engine operation requires the determination of drag increase due to ice accretion on inoperative wind milling engine fan blade and guide vane.
Technical Paper

Analysis of the Effect of Age on Shuttle Orbiter Lithium Hydroxide Canister Performance

2005-07-11
2005-01-2768
Recent efforts have been pursued to establish the usefulness of Space Shuttle Orbiter lithium hydroxide (LiOH) canisters beyond their certified two-year shelf life, at which time they are currently considered “expired.” A stockpile of Orbiter LiOH canisters are stowed on the International Space Station (ISS) as a backup system for maintaining ISS carbon dioxide Canisters with older (CO2) control. Canister with older pack dates must routinely be replaced with newly packed canisters off-loaded from the Orbiter Middeck. Since conservation of upmass is critical for every mission, the minimization of canister swap-out rate is paramount. LiOH samples from canisters with expired dates that had been returned from the ISS were tested for CO2 removal performance at the NASA Johnson Space Center (JSC) Crew and Thermal Systems Division (CTSD). Through this test series and subsequent analysis, performance degradation was established.
Technical Paper

A Novel Repair Technique for the Internal Thermal Control System Dual-Membrane Gas Trap

2005-07-11
2005-01-3079
A dual-membrane gas trap is currently used to remove gas bubbles from the Internal Thermal Control System (ITCS) coolant on board the International Space Station (ISS). The gas trap consists of concentric tube membrane pairs, comprised of outer hydrophilic tubes and inner hydrophobic fibers. Liquid coolant passes through the outer hydrophilic membrane, which traps the gas bubbles. The inner hydrophobic fiber allows the trapped gas bubbles to pass through and vent to the ambient atmosphere in the cabin. The gas trap was designed to last for the entire lifetime of the ISS, and therefore was not designed to be repaired. However, repair of these gas traps is now a necessity due to contamination from the on-orbit ITCS fluid and other sources on the ground as well as a limited supply of flight gas traps. This paper describes a novel repair technique that has been developed that will allow the refurbishment of contaminated gas traps and their return to flight use.
Technical Paper

International Space Station (ISS) Extravehicular Activity (EVA) Gas Usage

2005-07-11
2005-01-2897
International Space Station (ISS) Crewmembers perform one of three denitrogenation protocols prior to performing Extravehicular Activities (EVAs) using the International Space Station (ISS) Airlock. The three denitrogenation protocols are: a) Exercise, b) Campout, and c) In-suit. EVA gas usage is categorized into Denitrogenation, Extravehicular Mobility Unit (EMU) oxygen use during EVAs, and air loss gas usage. The amount of gas usage depends on the denitrogenation protocol that is used. Each protocol's gas usage will differ as a result of different requirements of denitrogenation and EMU support. Flight data is correlated with theoretical values when it is available. The correlation to flight data provides a validation of the analysis data. Theoretical and actual gas usages from the ISS were calculated for EVAs out of the Airlock during Stage 7A to Stage 11A. Components of denitrogenation and EMU support gas usage are included.
Technical Paper

Node 1 With Advanced Resistive Exercise Device Computational Fluid Dynamics Modeling

2005-07-11
2005-01-2798
This CFD study is aimed at evaluation of the ventilation characteristics within the ISS Node 1 with the Advanced Resistive Exercise Device (ARED) protrusions into ECLS keep-out zones. An assessment of Node 1 airflow characteristics in the presence of the ARED and a human body simulation model has been performed for the current on-orbit configuration of the Node 1 ventilation system. Both the quantitative velocity distribution analysis and qualitative three-dimensional airflow evaluation have shown that the installation of the ARED in the Node 1 radial bay produces a minimal impact on the cabin ventilation characteristics and the crew.
Technical Paper

Universal Splice Machine

2007-09-17
2007-01-3782
There is an increasing demand in the aerospace industry for automated machinery that is portable, flexible and light. This paper will focus on a joint project between BROETJE-Automation and Boeing called the Universal Splice Machine (USM). The USM is a portable, flexible and lightweight automated drilling and fastening machine for longitudinal splices. The USM is the first machine of its kind that has the ability not only to drill holes without the need to deburr, (burrless drilling) but also to insert fasteners. The Multi Function End Effector (MFEE) runs on a rail system that is mounted directly on the fuselage using a vacuum cup system. Clamp up is achieved through the use of an advanced electromagnet. A control cart follows along next to the fuselage and includes an Automated Fastener Feeding System. This paper will show how this new advancement has the capabilities to fill gaps in aircraft production that automation has never reached before.
Technical Paper

Development of Portable and Flexible Track Positioning System for Aircraft Manufacturing Processes

2007-09-17
2007-01-3781
The Boeing Company has recently developed a portable positioning system based upon its patented flexible vacuum track technology, in support of its commitment to lean manufacturing techniques. The positioning system, referred to as Mini Flex Track, was initially developed as an inexpensive drilling system that minimizes machine setup time, does not require extensive operator training due to its simple user interface, is general purpose enough to be used in varying airplane applications, and meets strict accuracy requirements for aircraft manufacturing. The system consists of a variable length vacuum track that conforms to a range of contours, a two-axis numerically-controlled positioning carriage that controls machine motion, an additional rail perpendicular to the vacuum rail that provides transverse motion, and an end effector that can perform various tasks.
Technical Paper

Verification of Supply Chain Quality for Perishable Tools

2007-09-17
2007-01-3813
Increased emphasis on standardizing processes and controlling variability in production operations includes validating perishable tools used in daily operations. Even though dealing with reputable manufacturers, many factors including communication, custom specifications and personnel turnover can lead to the perpetuation of mistakes if errors are not discovered and corrective action implemented. However, inspection is costly and inspection costs far outweigh many item costs unless considering product defects. A beneficial balance may be obtained by employing statistical sampling techniques similar to ISO 2859 [1] to verify the quality of incoming tools.
Technical Paper

The 747-400 Dreamlifter - Overview & Mission

2007-09-17
2007-01-3888
The development of new commercial airliners is a very risky proposition. To get it right, airframe manufacturers must balance new technologies and manufacturing methods with global participation and business considerations. The 787 is Boeing's popular new wide body aircraft incorporating state of the art composites design and manufacturing methods. But new technology alone is not enough. A new logistics system was needed to integrate global partners in order to fully benefit from new technologies. The Boeing 747-400 Dreamlifter is a special purpose 747-400 modified to transport Boeing 787 airplane components through various stages of manufacturing.
Technical Paper

A Comparison of the Radiation Environments in Deep Space

2007-07-09
2007-01-3114
Both humans and onboard radiosensitive systems (electronics, materials, payloads and experiments) are exposed to the deleterious effects of the harsh space radiations found in the space environment. The purpose of this paper is to present the space radiation environment extended to deep space based on environment models for the moon, Mars, Jupiter, and Saturn and compare these radiation environments with the earth's radiation environment, which is used as a comparative baseline. The space radiation environment consists of high-energy protons and electrons that are magnetically “trapped” in planetary bodies that have an intrinsic magnetic field; this is the case for earth, Jupiter, and Saturn (the moon and Mars do not have a magnetic field). For the earth this region is called the “Van Allen belts,” and models of both the trapped protons (AP-8 model) and electrons (AE-8 model) have been developed.
Technical Paper

Improvement of Risk Assessment from Space Radiation Exposure for Future Space Exploration Missions

2007-07-09
2007-01-3116
Protecting astronauts from space radiation exposure is an important challenge for mission design and operations for future exploration-class and long-duration missions. Crew members are exposed to sporadic solar particle events (SPEs) as well as to the continuous galactic cosmic radiation (GCR). If sufficient protection is not provided the radiation risk to crew members from SPEs could be significant. To improve exposure risk estimates and radiation protection from SPEs, detailed evaluations of radiation shielding properties are required. A model using a modern CAD tool ProE™, which is the leading engineering design platform at NASA, has been developed for this purpose. For the calculation of radiation exposure at a specific site, the cosine distribution was implemented to replicate the omnidirectional characteristic of the 4π particle flux on a surface.
Technical Paper

Haptics, Instrumentation, and Simulation: Technologies for Enhanced Hand Drilling Training

1999-06-05
1999-01-2283
A fundamental part of airplane manufacturing involves hand drilling of holes for fasteners (bolts and rivets). The integrity of a fastener depends on the quality of its hole, which must be properly positioned, have a circular diameter of correct dimension, and be free of surface flaws and contaminants. A common method of drilling training is for a student to drill holes under the supervision of an instructor who inspects or measures the holes and makes suggestions for improving technique. This training method has proven to be effective, but it is time-consuming and requires considerable personal attention. We have devised instrumentation to monitor critical parameters (drill orientation and forces) so that a student can receive instantaneous visual feedback. This real-time feedback provides the student a better understanding of the drilling process and allows him or her to quickly make improvements.
Technical Paper

Portable Fastener Delivery and Installation System

2003-09-08
2003-01-2953
The Portable Fastener Delivery System or PFDS, has been developed at the Boeing St. Louis facility to streamline the manual fastener installation process. The PFDS delivers various fasteners, on demand, through a delivery tube to an installation tool used by the operator to install the fasteners in an aircraft assembly. This paper describes the PFDS in its current configuration, along with the associated Huck® International (now Alcoa Fastening Systems) installation tooling, as it is being implemented on the F/A-18E/F Nosebarrel Skinning application. As a “portable” system, the PFDS cart can be rolled to any location on the shop floor it might be needed. The system uses a removable storage cassette to cache many sizes and types of fasteners in the moderate quantities that might be required for a particular assembly task. The operator begins the installation sequence by calling for the particular fastener grip length needed using a wireless control pendant.
Technical Paper

Post-Flight Sampling and Loading Characterization of Trace Contaminant Control Subassembly Charcoal

2003-07-07
2003-01-2487
Trace chemical contaminants produced by equipment offgassing and human metabolic processes are removed from the atmosphere of the International Space Station's U.S. Segment by a trace contaminant control subassembly (TCCS). The TCCS employs a combination of physical adsorption, thermal catalytic oxidation, and chemical adsorption processes to accomplish its task. A large bed of granular activated charcoal is a primary component of the TCCS. The charcoal contained in this bed, known as the charcoal bed assembly (CBA), is expendable and must be replaced periodically. Pre-flight engineering analyses based upon TCCS performance testing results established a service life estimate of 1 year. After nearly 1 year of cumulative in-flight operations, the first CBA was returned for refurbishment. Charcoal samples were collected and analyzed for loading to determine the best estimate for the CBA's service life.
X