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At least 631 records · Page 35

Immutable Secure Data Exchange and Storage for UAM Environments

Urban Air Mobility (UAM) has become a focus for the next generation of aerial passenger transportation. UAM operations will be leveraging a service-based architecture for airspace solutions. The UAM environment will leverage diverse communications and system access approaches. These approaches include independent Providers of Services for UAM and supplemental data service providers that exchange data between themselves and UAM operators. This research focuses on the secure data exchange and storage of this decentralized UAM environment to address these challenges. This research intends to leverage a permissioned blockchain approach to address cybersecurity threats that may impact a UAM environment.

Urban Air Mobility↗

Advanced Air Mobility Vertiport Considerations: A List and Overview

Advanced air mobility (AAM) is an emerging field in aeronautics that involves utilizing small aircraft for everyday transportation and other services, and many AAM aircraft are envisioned to take off and land at new infrastructure termed vertiports. This paper describes a variety of considerations related to AAM vertiports that need to be considered in the planning for and deployment of vertiports in practice. The factors include siting, design, regulations, safety, environmental impact, social acceptance, equity, and operational integration factors. Over 450 considerations were compiled from Subject Matter Experts (SMEs) participating in NASA’s AAM Ecosystem Working Groups (AEWGs) in October 2021. This paper consolidates these considerations and broadly disseminates the valuable knowledge of these SMEs. These considerations can be used by researchers to conduct demand and network analysis, local transportation planners to develop AAM networks for their community, and the AAM ecosystem members to identify policy, standards, and research gaps.

vertiport considerations↗

DMSK Receiver For Mobile/Satellite Service

Receiver for 2.4-kbit/s differential minimum-shift keying (DMSK) and Gaussian minimum-shift keying(GMSK) suitable for communication between land-mobile stations via geostationary satellites. Operating on phase-shifted signal in 800-MHz band, in presence of fading and Doppler frequency shifts, receiver compact, makes efficient use of frequency spectrum, and wastes little power. Receiver design implemented in very-large-scale-integrated circuits. Basic DMSK receiver design relies on baseband rather than intermediate-frequency processing of in-phase and quadrature signal components because phase errors due to differential delays smaller at baseband.

Davarian, Faramaz↗

Recent technical advances in general purpose mobile Satcom aviation terminals

A second general aviation amplitude companded single sideband (ACSSB) aeronautical terminal was developed for use with the Ontario Air Ambulance Service (OAAS). This terminal is designed to have automatic call set up and take down and to interface with the Public Service Telephone Network (PSTN) through a ground earth station hub controller. The terminal has integrated RF and microprocessor hardware which allows such functions as beam steering and automatic frequency control to be software controlled. The terminal uses a conformal patch array system to provide almost full azimuthal coverage. Antenna beam steering is executed without relying on aircraft supplied orientation information.

Sydor, John T.↗

In-space Servicing, Assembly, and Manufacturing (ISAM) State of Play 2022 Edition

The future of spaceflight will yield increasingly more ambitious missions to support civil, national security, and commercial space sectors. Achieving these ambitious missions is not feasible using the traditional paradigm of launching an integrated, fully functioning system on a single launch vehicle. For example, science and human exploration missions will desire payloads that are larger than any foreseeable launch vehicle fairing, national security missions will require persistent assets that are mobile and resilient, and commercial space missions will require cost-effective ways to update to the latest technology on orbit. In-space Servicing, Assembly, and Manufacturing (ISAM) can vastly expand the performance, availability, and lifetime of space systems compared to the traditional paradigm of launching an asset with no intent to ever touch it again. ISAM capabilities foster an ecosystem that changes the space operations paradigm, creating the foundation for sustainable exploration and serving as a multiplier for other capabilities like space logistics, power generation, and reusability. Previous achievements in ISAM have enabled ambitious human and robotic space missions. NASA’s International Space Station (ISS) operations and maintenance, servicing missions of the Hubble Space Telescope (HST), and Northrop Grumman’s Mission Extension Vehicle (MEV) demonstrate the dramatic operational missions that can be achieved using ISAM capabilities. Many current and upcoming flight demonstrations are advancing areas that will enable the next generation of civil, national security, and commercial space missions. This document describes the current state of ISAM missions, capabilities, and developments. Compiling and organizing the available ISAM capabilities will help mission designers incorporate ISAM technologies into their concepts, create the starting point for technology development plans and roadmaps, and provide technologists a survey of the field they are developing. This document divides the ISAM capabilities into 11 capability areas that describe the functions or activities that would be performed in space using ISAM. This version of the ISAM State of Play is part of a continuing journey to encourage the use of ISAM capabilities in space. Compiling and organizing the current state of ISAM provides a simple resource for those working in the ISAM ecosystem to ensure that the advancements being made build upon the investments of the past. The state of play is ever changing as new capabilities are developed, and this document will be periodically updated to ensure that it is relevant to those who need it in the future.

ISAM↗

Robonaut 2 on the International Space Station: Status Update and Preparations for IVA Mobility

Robotics engineers, ground controllers and International Space Station (ISS) crew have been running successful experiments using Robonaut 2 (R2) on-board the ISS for more than a year. This humanoid upper body robot continues to expand its list of achievements and its capabilities to safely demonstrate maintenance and servicing tasks while working alongside human crewmembers. The next phase of the ISS R2 project will transition from a stationary Intra Vehicular Activity (IVA) upper body using a power/data umbilical, to an IVA mobile system with legs for repositioning, a battery backpack power supply, and wireless communications. These upgrades will enable the R2 team to evaluate hardware performance and to develop additional control algorithms and control verification techniques with R2 inside the ISS in preparation for the Extra Vehicular Activity (EVA) phase of R2 operations. As R2 becomes more capable in assisting with maintenance tasks, with minimal supervision, including repositioning itself to different work sites, the ISS crew will be burdened with fewer maintenance chores, leaving them more time to conduct other activities. R2's developers at the Johnson Space Center (JSC) are preparing the R2 IVA mobility hardware and software upgrades for delivery to the ISS in late 2013. This paper summarizes R2 ISS achievements to date, briefly describes the R2 IVA mobility upgrades, and discusses the R2 IVA mobility objectives and plans.

Ahlstrom, Thomas D.↗

Lightning Protection System for Space Shuttle

The suitability and cost effectiveness of using a lightning mast for the shuttle service and access tower (SSAT) similar to the type used for the Apollo Soyuz Test Project (ASTP) mobile launcher (ML) was evaluated. Topics covered include: (1) ASTP launch damage to mast, mast supports, grounded overhead wires, and the instrumentation system; (2) modifications required to permit reusing the ASTP mast on the SSAT; (3) comparative costing factors per launch over a 10 year period in repetitive maintenance and refurbishment of the existing and modified masts, mast supports, grounded overhead wires, and ground instrumentation required to sustain mechanical and electrical integrity of the masts; (4) effects of blast testing samples of the ASTP ML type mast (corrosion and electrical flashover); (5) comparison of damages from ASTP launch and from blast testing.

Source record↗

EMU processing - A myth dispelled

The refurbishment-and-checkout 'processing' activities entailed by the Space Shuttle Extravehicular Mobility Units (EMUs) are currently significantly more modest, at 1050 man-hours, than when Space Shuttle services began (involving about 4000 man-hours). This great improvement in hardware efficiency is due to the design or modification of test rigs for simplification of procedures, as well as those procedures' standardization, in conjunction with an increase in hardware confidence which has allowed the extension of inspection, service, and testing intervals. Recent simplification of the hardware-processing sequence could reduce EMU processing requirements to 600 man-hours in the near future.

Peacock, Paul R.↗

Continuous motion using task-directed stereo vision

The performance of autonomous mobile robots performing complex navigation tasks can be dramatically improved by directing expensive sensing and planning in service of the task. The task-direction algorithms can be quite simple. In this paper we describe a simple task-directed vision system which has been implemented on a real outdoor robot which navigates using stereo vision. While the performance of this particular robot was improved by task-directed vision, the performance of task-directed vision in general is influenced in complex ways by many factors. We briefly discuss some of these, and present some initial simulated results.

Gat, Erann↗

Construction bidding cost of KSC's space shuttle facilities

The bidding cost of the major Space Transportation System facilities constructed under the responsibility of the John F. Kennedy Space Center (KSC) is described and listed. These facilities and Ground Support Equipment (GSE) are necessary for the receiving, assembly, testing, and checkout of the Space Shuttle for launch and landing missions at KSC. The Shuttle launch configuration consists of the Orbiter, the External Tank, and the Solid Rocket Boosters (SRB). The reusable Orbiter and SRB's is the major factor in the program that will result in lowering space travel costs. The new facilities are the Landing Facility; Orbiter Processing Facility; Orbiter Approach and Landing Test Facility (Dryden Test Center, California); Orbiter Mating Devices; Sound Suppression Water System; and Emergency Power System for LC-39. Also, a major factor was to use as much Apollo facilities and hardware as possible to reduce the facilities cost. The alterations to existing Apollo facilities are the VAB modifications; Mobile Launcher Platforms; Launch Complex 39 Pads A and B (which includes a new concept - the Rotary Service Structure), which was featured in ENR, 3 Feb. 1977, 'Hinged Space Truss will Support Shuttle Cargo Room'; Launch Control Center mods; External Tank and SRB Processing and Storage; Fluid Test Complex mods; O&C Spacelab mods; Shuttle mods for Parachute Facility; SRB Recovery and Disassembly Facility at Hangar 'AF'; and an interesting GSE item - the SRB Dewatering Nozzle Plug Sets (Remote Controlled Submarine System) used to inspect and acquire for reuse of SRB's.

Brown, Joseph Andrew↗

Architecture of the TELEDESIC satellite system

There is a significant worldwide demand for broadband communications capacity. Teledesic plans to meet this demand using a constellation of 924 low-Earth orbit (LEO) satellites operating in Ka-band (30/20 GHz). The Teledesic network will provide 'fiber-like' service quality, including low transmission delay, high data rates, and low bit error rates, to fixed and mobile users around the world starting in 2001.

Sturza, Mark A.↗

Space-to-Space Communications System

The Space-to-Space Communications System (SSCS) is an Ultra High Frequency (UHF) Time-Division-Multiple Access (TDMA) system that is designed, developed, and deployed by the NASA Johnson Space Center (JSC) to provide voice, commands, telemetry and data services in close proximity among three space elements: International Space Station (ISS), Space Shuttle Orbiter, and Extravehicular Mobility Units (EMU). The SSCS consists of a family of three radios which are, Space-to-Space Station Radio (SSSR), Space-to-Space Orbiter Radio (SSOR), and Space-to-Space Extravehicular Mobility Radio (SSER). The SSCS can support up to five such radios at a time. Each user has its own time slot within which to transmit voice and data. Continuous Phase Frequency Shift Keying (CPFSK) carrier modulation with a burst data rate of 695 kbps and a frequency deviation of 486.5 kHz is employed by the system. Reed-Solomon (R-S) coding is also adopted to ensure data quality. In this paper, the SSCS system requirements, operational scenario, detailed system architecture and parameters, link acquisition strategy, and link performance analysis will be presented and discussed

Kwei tU↗

Evolution of the Florida Launch Site Architecture: Embracing Multiple Customers, Enhancing Launch Opportunities

The impending conclusion of the Space Shuttle Program and the Constellation Program cancellation unveiled in the FY2011 President's budget created a large void for human spaceflight capability and specifically launch activity from the Florida launch Site (FlS). This void created an opportunity to re-architect the launch site to be more accommodating to the future NASA heavy lift and commercial space industry. The goal is to evolve the heritage capabilities into a more affordable and flexible launch complex. This case study will discuss the FlS architecture evolution from the trade studies to select primary launch site locations for future customers, to improving infrastructure; promoting environmental remediation/compliance; improving offline processing, manufacturing, & recovery; developing range interface and control services with the US Air Force, and developing modernization efforts for the launch Pad, Vehicle Assembly Building, Mobile launcher, and supporting infrastructure. The architecture studies will steer how to best invest limited modernization funding from initiatives like the 21 st elSe and other potential funding.

Colloredo, Scott↗

Progress on the Development of Future Airport Surface Wireless Communications Network

Continuing advances in airport surface management and improvements in airport surface safety are required to enable future growth in air traffic throughout the airspace, as airport arrival and departure delays create a major system bottleneck. These airport management and safety advances will be built upon improved communications, navigation, surveillance, and weather sensing, creating an information environment supporting system automation. The efficient movement of the digital data generated from these systems requires an underlying communications network infrastructure to connect data sources with the intended users with the required quality of service. Current airport surface communications consists primarily of buried copper or fiber cable. Safety related communications with mobile airport surface assets occurs over 25 kHz VHF voice and data channels. The available VHF spectrum, already congested in many areas, will be insufficient to support future data traffic requirements. Therefore, a broadband wireless airport surface communications network is considered a requirement for the future airport component of the air transportation system. Progress has been made on defining the technology and frequency spectrum for the airport surface wireless communications network. The development of a test and demonstration facility and the definition of required testing and standards development are now underway. This paper will review the progress and planned future work.

Kerczewski, Robert J.↗

AAtS over AeroMACS Technology Trials on the Airport Surface

Air-Ground component of SWIM; Enables enhanced two-way information exchanges between flight operators, aircrew, and ATSP (TFM); Used in all flight domains including pre-departure and post-arrival; Aircrew active in CDM; For strategic planning, advisory information; Not for command control (data voice) Wireless communications system for airport surface; Family member of Mobile WiMAX: (IEEE802.16e), Band 5091-5150 MHz, Bandwidth 5 MHz - TDDOFDMA - Adaptive Modulation and Coding - Quality of Service (QoS)

Wireless Communications↗

A Prognostics Framework for Battery Health Monitoring Integrated with Thermal Modeling

Urban Air Mobility (UAM) promises to revolutionize transportation in major cities, offering passenger travel, cargo delivery, and emergency medical services through a network of electric vertical takeoff and landing (eVTOL) aircraft. However, the limited range of current eVTOLs, due to the low specific energy of lithium-ion batteries along with a possibility of thermal runaway conditions poses significant safety concerns, leading to potentially compromising operational safety. To address this critical challenge, researchers are actively evaluating the impact of flight and environmental conditions on onboard lithium-ion battery health. This involves carefully assessing the performance of battery packs under laboratory and operational conditions for developing models to estimate future health using prognostics framework. This study examines the effectiveness of evaluating battery degradation leading to catastrophic failures under varying operational conditions in laboratory. These are captured using physics based models of underlying phenomenons and integrated into the prognostics framework. A fully charged battery undergoes controlled discharge cycles at varying C-rates based on the simulated power draw profile, with current and voltage, temperature data recorded throughout the experiment. The observed data provides valuable insights into how different operating conditions and mission profiles affect battery performance. This information is crucial for developing strategies to optimize battery systems, enhance range, and ultimately ensure the safe and reliable operation of UAM vehicles.

Thermal Modeling↗

A Prognostics Framework for Battery Health Monitoring Integrated with Thermal Modeling

Urban Air Mobility (UAM) promises to revolutionize transportation in major cities, offering passenger travel, cargo delivery, and emergency medical services through a network of electric vertical takeoff and landing (eVTOL) aircraft. However, the limited range of current eVTOLs, due to the low specific energy of lithium-ion batteries along with a possibility of thermal runaway conditions poses significant safety concerns, leading to potentially compromising operational safety. To address this critical challenge, researchers are actively evaluating the impact of flight and environmental conditions on onboard lithium-ion battery health. This involves carefully assessing the performance of battery packs under laboratory and operational conditions for developing models to estimate future health using prognostics framework. This study examines the effectiveness of evaluating battery degradation leading to catastrophic failures under varying operational conditions in laboratory. These are captured using physics based models of underlying phenomenons and integrated into the prognostics framework. A fully charged battery undergoes controlled discharge cycles at varying C-rates based on the simulated power draw profile, with current and voltage, temperature data recorded throughout the experiment. The observed data provides valuable insights into how different operating conditions and mission profiles affect battery performance. This information is crucial for developing strategies to optimize battery systems, enhance range, and ultimately ensure the safe and reliable operation of UAM vehicles.

Thermal Modeling↗

A Prognostics Framework for Battery Health Monitoring Integrated with Thermal Modeling

Urban Air Mobility (UAM) promises to revolutionize transportation in major cities, offering passenger travel, cargo delivery, and emergency medical services through a network of electric vertical takeoff and landing (eVTOL) aircraft. However, the limited range of current eVTOLs, due to the low specific energy of lithium-ion batteries along with a possibility of thermal runaway conditions poses significant safety concerns, leading to potentially compromising operational safety. To address this critical challenge, researchers are actively evaluating the impact of flight and environmental conditions on onboard lithium-ion battery health. This involves carefully assessing the performance of battery packs under laboratory and operational conditions for developing models to estimate future health using prognostics framework. This study examines the effectiveness of evaluating battery degradation leading to catastrophic failures under varying operational conditions in laboratory. These are captured using physics based models of underlying phenomenons and integrated into the prognostics framework. A fully charged battery undergoes controlled discharge cycles at varying C-rates based on the simulated power draw profile, with current and voltage, temperature data recorded throughout the experiment. The observed data provides valuable insights into how different operating conditions and mission profiles affect battery performance. This information is crucial for developing strategies to optimize battery systems, enhance range, and ultimately ensure the safe and reliable operation of UAM vehicles.

Thermal Modeling↗