Results 41 to 50 of about 301,038 (298)

Displaced geostationary orbit design using hybrid sail propulsion [PDF]

, 2011
Because of an increase in the number of geostationary spacecraft and the limits imposed by east–west spacing requirements, the geostationary orbit is becoming congested. To increase its capacity, this paper proposes to create new geostationary slots by
Becerra V. M., Becerra V. M., Colin R. McInnes, Forward R. L., Heiligers J., James D. Biggs, Jeannette Heiligers, Jehn R., Leipold M., Macdonald M., Matteo Ceriotti, McKay R., Murphy D. M., Newton K., Yashko G. J.   +14 more
core   +1 more source

Aerocapture: Enabling Small Spacecraft Direct Access to Low-Circular Orbits for Planetary Constellations

Aerospace, 2023
Small satellite constellations in multiple-inclination, low-circular orbits around Mars and Venus have the potential to perform a range of high-value science investigations within cost-constrained missions.
A. Girija, S. Saikia, J. Longuski
semanticscholar   +1 more source

Space Propulsion Technology for Small Spacecraft

Proceedings of the IEEE, 2018
As small satellites become more popular and capable, strategies to provide in-space propulsion increase in importance. Applications range from orbital changes and maintenance, attitude control and desaturation of reaction wheels to drag compensation and ...
D. Krejci, P. Lozano
semanticscholar   +1 more source

Generation of optimal trajectories for Earth hybrid pole sitters [PDF]

, 2011
A pole-sitter orbit is a closed path that is constantly above one of the Earth's poles, by means of continuous low thrust. This work proposes to hybridize solar sail propulsion and solar electric propulsion (SEP) on the same spacecraft, to enable such a ...
Becerra V. M., Becerra V. M., Betts J. T., Colin R. McInnes, Gershman R., Lazzara M. A., Leipold M., Leiter H. J., Matteo Ceriotti, McInnes C. R., Mori O., Simo J., Wertz J. R.   +12 more
core   +1 more source

WATER AS AN ENVIRONMENTALLY FRIENDLY PROPELLANT FOR A MULTI-FUNCTIONAL SPACECRAFT ARCHITECTURE

International Journal of Energetic Materials and Chemical Propulsion, 2023
Water can be utilized as spacecraft propellant to dramatically reduce the environmental impact of constructing and operating a satellite. In this work, a multi-mode chemical-electrical propulsion system, in which water was used as the propellant in both ...
Jesús Manuel Muñoz Tejeda, A. Schwertheim, A. Knoll   +2 more
semanticscholar   +1 more source

Numerical comparison of exhaust plume flow behaviors of small monopropellant and bipropellant thrusters. [PDF]

PLoS ONE, 2017
In general, a space propulsion system has a crucial role in the normal mission operations of a spacecraft. Depending on the types and number of propellants, a monopropellant and a bipropellant thrusters are mostly utilized for low thrust liquid rocket ...
Kyun Ho Lee
doaj   +1 more source

A review of air-breathing electric propulsion: from mission studies to technology verification

Journal of Electric Propulsion, 2022
Air-breathing electric propulsion (ABEP) allows for lowering the altitude of spacecraft operations below 250 km, in the so-called Very Low Earth Orbits (VLEOs).
T. Andreussi, E. Ferrato, V. Giannetti
semanticscholar   +1 more source

From the Discovery of the Giant Magnetocaloric Effect to the Development of High‐Power‐Density Systems

Advanced Materials Technologies, EarlyView.
The article overviews past and current efforts on caloric materials and systems, highlighting the contributions of Ames National Laboratory to the field. Solid‐state caloric heat pumping is an innovative method that can be implemented in a wide range of cooling and heating applications.
Agata Czernuszewicz, Yaroslav Mudryk, Jun Cui, Lucas Griffith, Duane D. Johnson, Julie Slaughter   +5 more
wiley   +1 more source

Temperature‐Dependent Zinc Oxide Cathodoluminescence: Toward Compact Wavelength‐Tunable Solid‐State Photoionization Sources

Advanced Optical Materials, EarlyView.
A proof‐of‐concept of a thermally‐tunable cathodoluminescence‐based light source is demonstrated using a wide‐bandgap z‐cut ZnO crystal as anode, resulting in the ultraviolet (UV) emission peak shifting from 398 nm to ~409 nm (3.115‐3.032 eV). Our results establish the feasibility of a compact, field‐deployable UV source with potential for gas sensing ...
Rui M. R. Pinto, Aritz Retolaza, João Cunha, Pedro Matos, Júlio Silva, Diana Silva, Rosana Alves Dias, K. B. Vinayakumar   +7 more
wiley   +1 more source

Retarding potential analyzer: Principles, designs, and space applications

AIP Advances, 2020
The main emphasis of this paper is on the use of Retarding Potential Analyzers (RPAs) for measuring the electron and ion distribution functions, density, and temperature of space plasmas and the charging level of spacecraft surfaces interacting with the ...
Shu T. Lai, Catherine Miller
doaj   +1 more source