Results 261 to 270 of about 31,908 (302)

Mosses in Low Earth Orbit

2019
As a part of the European Space Agency mission "EXPOSE-R2" on the International Space Station (ISS), the BIOMEX (Biology and Mars Experiment) experiment investigates the habitability of Mars and the limits of life. In preparation for the mission, experimental verification tests and scientific verification tests simulating different combinations of ...
Huwe, Björn, Fiedler, Annelie, Moritz, Sophie, Rabbow, Elke, de Vera, Jean-Pierre Paul, Joshi, Jasmin (Prof. Dr.)   +5 more
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To low earth orbit and beyond

IEEE Spectrum, 2014
NASA has found itself curiously earthbound of late. Since it retired the space shuttles in 2011, the U.S. space agency has had to send astronauts to the International Space Station aboard Russian rockets.
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Low Earth Orbits (LEO)

2010 20th International Crimean Conference "Microwave & Telecommunication Technology", 2010
The handheld portable satellite phones, semifixed satellite payphones and remote offices including Satellite Broadband, Satellite Asset Tracking and Fleet Management (SATFM), Satellite Supervisory Control and Data Acquisition (SCADA) or Machine-to-Machine (M2M) monitoring, control, command and logistics system are a very new communications tools ...
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Performance of a BGO detector in low Earth orbit

IEEE Transactions on Nuclear Science, 1991
A 7.6-cm*7.6-cm BGO (bismuth germanate) detector was flown in the middeck of the Space Shuttle Columbia August 8-13, 1989, as part of the Shuttle Activation Monitor (SAM) experiment. One of the goals of this experiment was to compare the performance of the BGO to that of NaI in the same environment.
P.S. Haskins, J.E. McKisson, D.W. Ely, A.G. Weisenberger, T.A. Ballard, C.S. Dyer, P.R. Truscott, R.B. Piercey, A.V. Ramayya, D.C. Camp   +9 more
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Evolved spacecraft trajectories for low earth orbit

Proceedings of the 2014 Annual Conference on Genetic and Evolutionary Computation, 2014
In this paper we use Differential Evolution (DE), with best evolved results refined using a Nelder-Mead optimization, to solve complex problems in orbital mechanics relevant to low Earth orbits (LEO). A class of so-called 'Lambert Problems' is examined.
David W. Hinckley Jr., Karol Zieba, Darren L. Hitt, Margaret J. Eppstein   +3 more
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Enhancing GNSS by integrating low Earth orbiters

2022
In dieser Arbeit wird eine Verbesserung der globalen Satellitennavigationssysteme (GNSS) durch die Einbindung von Satelliten in niedrigen Erdumlaufbahnen (LEOs) in eine gemeinsame präzise Bahnbestimmung (POD) vorgestellt. Das von den Vereinigten Staaten betriebene Global Positioning System (GPS) wird stellvertretend für alle GNSS untersucht.
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Beyond low earth orbit. An overview of orbit-to-orbit stages

Acta Astronautica, 1986
New developments in upper stages are discussed. Tables revealing the dimensions, engine types, total thrust, weight, payload, and sponsor for developed and planned upper stages compatible with Space Transportation System (STS) or expendable launch vehicles are presented.
Joseph P. Loftus, Warren L. Brasher
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Performance of Low Earth Orbit Satellite Systems with Coding

Wireless Personal Communications, 2002
The effect of block, convolutional and Turbo coding on the probability of error and the capacity are investigated for CDMA Low Earth Orbit (LEO) Satellite systems. The model employed assumes a contaminated Gaussian traffic model to be more compatible with different population areas.
Hebatallah M. Mourad, Abdel Aziz M. Al-Bassiouni, Sherief S. Emam, Emad K. Al-Hussaini   +3 more
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Yaliny's protocol for low earth orbit satellites

2015 IEEE East-West Design & Test Symposium (EWDTS), 2015
This paper presents a modification of CCSDS 131.2-R-2/DVB-S2 standard developed by Yaliny Engineering. The modification has special features — Doppler offset compensation with prior information, low latency synchronization scheme, which allows for its use on LEO satellites and patent-free LDPC codec.
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Precise Autonomous Orbit Control in Low Earth Orbit

AIAA/AAS Astrodynamics Specialist Conference, 2012
This paper analyses the problem of the autonomous absolute orbit control of a space- craft in low Earth orbit using different on-board feedback control systems. Three types of control are compared. The first implements an analytical control algorithm. The second and third controllers considered are the linear and the quadratic optimum regulator from
De Florio, S., D'Amico, S., Radice, G.
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