513 research outputs found
Twenty-first semiannual report to Congress, 1 January - 30 June 1969
Manned space flights, satellite observations, space sciences, and air traffic control - NASA report to Congress for 1 Jan. to 30 June 196
Abbreviations and acronyms guide
A selected list of abbreviations and acronyms in use throughout the Jet Propulsion Laboratory is presented. The compilation includes NASA and JPL facilities and organizations, federal government agencies, international organizations, engineering and scientific associations and societies, commercial organizations, and words and phrases with technical and financial applications
Contributions to deconfliction advanced U-space services for multiple unmanned aerial systems including field tests validation
Unmanned Aerial Systems (UAS) will become commonplace, the number of UAS
flying in European airspace is expected to increase from a few thousand to hundreds
of thousands by 2050. To prepare for this approaching, national and international
organizations involved in aerial traffic management are now developing new laws
and restructuring the airspace to incorporate UAS into civil airspace. The Single
European Sky ATM Research considers the development of the U-space, a crucial
step to enable the safe, secure, and efficient access of a large set of UAS into airspace.
The design, integration, and validation of a set of modules that contribute to our
UTM architecture for advanced U-space services are described in this Thesis. With
an emphasis on conflict detection and resolution features, the architecture is flexible,
modular, and scalable. The UTM is designed to work without the need for human
involvement, to achieve U-space required scalability due to the large number of expected
operations. However, it recommends actions to the UAS operator since, under
current regulations, the operator is accountable for carrying out the recommendations
of the UTM. Moreover, our development is based on the Robot Operating System
(ROS) and is open source.
The main developments of the proposed Thesis are monitoring and tactical deconfliction
services, which are in charge of identifying and resolving possible conflicts
that arise in the shared airspace of several UAS. By limiting the conflict search to a
local search surrounding each waypoint, the proposed conflict detection method aims
to improve conflict detection. By splitting the issue down into smaller subproblems
with only two waypoints, the conflict resolution method tries to decrease the deviation
distance from the initial flight plan. The proposed method for resolving potential threats is based on the premise that
UAS can follow trajectories in time and space properly. Therefore, another contribution
of the presented Thesis is an UAS 4D trajectory follower that can correct space
and temporal deviations while following a given trajectory. Currently, commercial autopilots
do not offer this functionality that allows to improve the airspace occupancy
using time as an additional dimension.
Moreover, the integration of onboard detect and avoid capabilities, as well as the
consequences for U-space services are examined in this Thesis. A module capable
of detecting large static unexpected obstacles and generating an alternative route to
avoid the obstacle online is presented.
Finally, the presented UTM architecture has been tested in both software-in-theloop
and hardware-in-the-loop development enviroments, but also in real scenarios
using unmanned aircraft. These scenarios were designed by selecting the most relevant
UAS operation applications, such as the inspection of wind turbines, power lines
and precision agriculture, as well as event and forest monitoring. ATLAS and El
Arenosillo were the locations of the tests carried out thanks to the European projects
SAFEDRONE and GAUSS.Los sistemas aéreos no tripulados (UAS en inglés) se convertirán en algo habitual. Se prevé que el
número de UAS que vuelen en el espacio aéreo europeo pase de unos pocos miles a cientos de
miles en 2050. Para prepararse para esta aproximación, las organizaciones nacionales e
internacionales dedicadas a la gestión del tráfico aéreo están elaborando nuevas leyes y
reestructurando el espacio aéreo para incorporar los UAS al espacio aéreo civil. SESAR (del inglés
Single European Sky ATM Research) considera el desarrollo de U-space, un paso crucial para
permitir el acceso seguro y eficiente de un gran conjunto de UAS al espacio aéreo.
En esta Tesis se describe el diseño, la integración y la validación de un conjunto de módulos que
contribuyen a nuestra arquitectura UTM (del inglés Unmanned aerial system Traffic Management)
para los servicios avanzados del U-space. Con un énfasis en las características de detección y
resolución de conflictos, la arquitectura es flexible, modular y escalable. La UTM está diseñada para
funcionar sin necesidad de intervención humana, para lograr la escalabilidad requerida por U-space
debido al gran número de operaciones previstas. Sin embargo, la UTM únicamente recomienda
acciones al operador del UAS ya que, según la normativa vigente, el operador es responsable de las
operaciones realizadas. Además, nuestro desarrollo está basado en el Sistema Operativo de Robots
(ROS en inglés) y es de código abierto.
Los principales desarrollos de la presente Tesis son los servicios de monitorización y evitación de
conflictos, que se encargan de identificar y resolver los posibles conflictos que surjan en el espacio
aéreo compartido de varios UAS. Limitando la búsqueda de conflictos a una búsqueda local
alrededor de cada punto de ruta, el método de detección de conflictos pretende mejorar la detección
de conflictos. Al dividir el problema en subproblemas más pequeños con sólo dos puntos de ruta, el
método de resolución de conflictos intenta disminuir la distancia de desviación del plan de vuelo
inicial.
El método de resolución de conflictos propuesto se basa en la premisa de que los UAS pueden
seguir las trayectorias en el tiempo y espacio de forma adecuada. Por tanto, otra de las aportaciones
de la Tesis presentada es un seguidor de trayectorias 4D de UAS que puede corregir las
desviaciones espaciales y temporales mientras sigue una trayectoria determinada. Actualmente, los
autopilotos comerciales no ofrecen esta funcionalidad que permite mejorar la ocupación del espacio
aéreo utilizando el tiempo como una dimensión adicional.
Además, en esta Tesis se examina la capacidad de integración de módulos a bordo de detección y
evitación de obstáculos, así como las consecuencias para los servicios de U-space. Se presenta un
módulo capaz de detectar grandes obstáculos estáticos inesperados y capaz de generar una ruta
alternativa para evitar dicho obstáculo.
Por último, la arquitectura UTM presentada ha sido probada en entornos de desarrollo de simulación,
pero también en escenarios reales con aeronaves no tripuladas. Estos escenarios se diseñaron
seleccionando las aplicaciones de operación de UAS más relevantes, como la inspección de
aerogeneradores, líneas eléctricas y agricultura de precisión, así como la monitorización de eventos y
bosques. ATLAS y El Arenosillo fueron las sedes de las pruebas realizadas gracias a los proyectos
europeos SAFEDRONE y GAUSS
Data distribution satellite
A description is given of a data distribution satellite (DDS) system. The DDS would operate in conjunction with the tracking and data relay satellite system to give ground-based users real time, two-way access to instruments in space and space-gathered data. The scope of work includes the following: (1) user requirements are derived; (2) communication scenarios are synthesized; (3) system design constraints and projected technology availability are identified; (4) DDS communications payload configuration is derived, and the satellite is designed; (5) requirements for earth terminals and network control are given; (6) system costs are estimated, both life cycle costs and user fees; and (7) technology developments are recommended, and a technology development plan is given. The most important results obtained are as follows: (1) a satellite designed for launch in 2007 is feasible and has 10 Gb/s capacity, 5.5 kW power, and 2000 kg mass; (2) DDS features include on-board baseband switching, use of Ku- and Ka-bands, multiple optical intersatellite links; and (3) system user costs are competitive with projected terrestrial communication costs
Space transportation system and associated payloads: Glossary, acronyms, and abbreviations
A collection of some of the acronyms and abbreviations now in everyday use in the shuttle world is presented. It is a combination of lists that were prepared at Marshall Space Flight Center and Kennedy and Johnson Space Centers, places where intensive shuttle activities are being carried out. This list is intended as a guide or reference and should not be considered to have the status and sanction of a dictionary
Aeronautics and Space Report of the President: Fiscal Year 1996 Activities
Topics considered include: (1) Space launch activities: space shuttle missions; expendable launch vehicles. (2) Space science: astronomy and space physics; solar system exploration. (3) Space flight and technology: life and microgravity sciences; space shuttle technology; reuseable launch vehicles; international space station; energy; safety and mission assurance; commercial development and regulation of space; surveillance. (4) Space communications: communications satellites; space network; ground networks; mission control and data systems. (5) Aeronautical activities: technology developments; air traffic control and navigation; weather-related aeronautical activities; flight safety and security; aviation medicine and human factors. (6) Studies of the planet earth: terrestrial studies and applications: atmospheric studies: oceanographic studies; international aeronautical and space activities; and appendices
Space flight research relevant to health, physical education, and recreation: With particular reference to Skylab's life science experiments
Data collected in the Skylab program relating to physiological stresses is presented. Included are routine blood measures used in clinical medicine as research type endocrine analyses to investigate the metabolic/endocrine responses to weightlessness. The daily routine of physical exercise, coupled with appropriate dietary intake, sleep, work, and recreation periods were considered essential in maintaining the crew's health and well being
Publications of the Jet Propulsion Laboratory July 1965 through July 1966
Bibliography on Jet Propulsion Laboratory technical reports and memorandums, space programs summary, astronautics information, and literature searche
Twentieth semiannual report to Congress, 1 July - 31 December 1968
Semiannual progress report for NASA programs 196
Acronym dictionary
This reference was originally compiled as a tool for abstracters who need to know the expansion of acronyms they may encounter in the texts they are analyzing. It is a general rule of abstracting at the NASA Center For Aerospace Information (CASI) that acronyms are expanded in the abstract to enhance both information content and searchability. Over the last 22 years, abstracters at CASI have recorded acronyms and their expansions as they were encountered in documents. This is therefore an ad-hoc reference, rather than a systematic collection of all acronyms related to aerospace science and technology
- …