Space Systems/loral, LLC

California Institute of Technology

Peter W Lord

Howard H Luh

Sina Barkeshli

Louis B Brydon

Dan M Goebel

David Younghee Oh

Evert C Nygren

Jorge Delgado

Christopher Bryan Stell

Vito J Jakstys

Bao Hoang

Levent Ersoy

Lee Charles Rotlisberger

Samuel R Moore

Gregory Alan Carr

Jeff Zaine

Denis Trofimov

A spacecraft includes a power train that includes a solar array, an electric propulsion subsystem, and a power conversion module. The power conversion module receives power from the solar array at a voltage, V; and delivers power to the electric propulsion subsystem at a voltage, V. The spacecraft is configured to operate at a varying distance, D, from the sun within the range of Dto D, Dbeing at least 1.3&#xd7;D. The solar array is configured to deliver power to the power conversion module at a voltage approximately equal to Vwhen the spacecraft is proximate to D.

Power train for deep space solar electric propulsion

An antenna system having a front reflector and a rear reflector arranged in tandem, a front feed for illuminating the front reflector, and a rear feed for illuminating the rear reflector. Each of the reflectors has a generally dish-shaped configuration, and the feeds are located in positions offset from axes of the respective reflectors. The front reflector is reflective to a first radiation, while being substantially transparent to a second radiation except for a fraction of the power of the second radiation. The fractional part of the second radiation is reflected from the first reflector as an interfering beam, the interfering beam being scanned away from a coverage region of a beam of the first radiation by an offset between the feeds. The radiations may differ in polarization or in frequency. There may be a complete shading of the rear reflector by the front reflector from the radiation of the rear feed to produce uniform illumination of the rear reflector for greater accuracy in a formation of a beam from the rear reflector. Six degrees of freedom in positioning and orientation of the reflectors and their feeds provides maximum design flexibility for obtaining a compact antenna.

Antenna system with plural reflectors

A method for designing a shaped dual reflector antenna comprising the initial selection of a hyperboloidal or ellipsoidal reflective surface profile for the main reflector such that the cross-polarization of the contoured output RF signal beam of the resulting antenna structure is reduced.

Antenna geometry for shaped dual reflector antenna

An antenna has one feed for an S-band electromagnetic signal, and a second feed constructed as an array of radiators to service two C-band signal channels. A subreflector having a microwave frequency selective surface (FSS) is placed in front of a main reflector. The C-band feed is constructed of an array of square aperture horns joined by separate transmit and receive barline beam-forming networks, and a meanderline polarizer to produce circularly polarized radiation patterns. Tapered ridges extend longitudinally along inner wall surfaces of each of the horns to provide increased bandwidth to the C-band feed. The frequency selective surface is constructed, typically, of a generally planar substrate of material transparent to electromagnetic radiation, and numerous metallic, generally annular, radiating elements, or resonators, arranged on the substrate in an array of repeating nested sets of the radiating elements. The lower frequency S-band feed is located behind and to the side of the subreflector for transmission of radiation via a folded optical path to the main reflector. The C-band feed is located in front of and to the side of the subreflector for transmission of radiation along a straight path through the FSS to the main reflector. The locating of the two feeds to the side of the subreflector permits the subreflector to be stowed by folding down upon the C-band feed, and the main reflector to be stowed by folding down upon both the S-band feed and the stowed subreflector.

Multiple band folding antenna

A self-supporting convex cover for spacecraft hardware is described. In the preferred embodiment, the cover is made of a laminated material. Strips of material are inserted into the laminate in a channel shape, such that sufficiently rigid box beam structures are formed in a pattern to hold the convex shape. Ribs of foam may be placed between a layer of the laminate and the strips of material to provide the channel shape. The cover is attached to the spacecraft hardware by one or more drawstrings which are laced through the perimeter of the cover. With appropriate materials, the resulting assembly is light, inexpensive, easy to assemble, and transparent to radio frequencies, yet sturdy enough to maintain its shape during launch.

Self-supporting convex cover for spacecraft

Growing community of inventors

Mountainview, CA, United States of America

Peter W Lord