Abstract: A method and apparatus for “ring fencing” an operating system, with any apps or programs running on that operating system, in such a way that all operations of the apps, programs, and operating system use real resources only with the permission or through the intermediation of a resource allocator programmed to allow only secure access to a known finite set of resources. The list of kinds of resources is short, and the list of resources is under the explicit control of the resource allocator, which is programmed with Communicating Sequential Processes techniques so as to give formally verifiable assurance of predefined security requirements. At the same time, the full features of the operating system are supported with minimal changes in its kernel and no changes in app or program binary code that accesses real resources via calls or bytecode that drives dynamic system libraries or a runtime environment.
Type:
Grant
Filed:
October 26, 2017
Date of Patent:
December 3, 2019
Assignee:
Space Sciences Corporation
Inventors:
Lawrence J. Dickson, Robert M. Fryer, Lindsay O. Quarrie
Abstract: A single-stage-to-orbit integrated launch and payload system is provided that includes a support structure, a propulsion system that is supported by the support structure and provides both launch propulsion and on-orbit payload propulsion, a control system that is supported by the support structure and controls both launch functions and on-orbit functions, and an electrical power system that is supported by the support structure and provides launch electrical power and on-orbit payload electrical power.
Abstract: A sun sensor for use in orbiting satellites provides accurate attitude control yet eliminates the use of complicated optical components. The improved accuracy results from adjustment of the relative positions of a slit or pinhole aperture and a cooperating linear array of photodetector elements to increase the operating range of the sun sensor. Enhanced accuracy is further achieved by the use of a relatively wide slit instead of complicated optical components, in conjunction with a processing procedure which uses the finite angular subtense of the sun to increase the accuracy of the attitude control of the satellite by the sun sensor. A further embodiment of the invention includes a sun sensor device having dual "pinhole" apertures which is particularly useful for attitude control of a spinning satellite.
Abstract: An earth sensor for use in orbiting satellites over an altitude range between low earth orbit (LEO) and geosynchronous orbit (GEO) and beyond employs a combination of both visible wavelength senor technology and infrared (IR) sensor technology to result in high accuracy capability. During the vast majority of an orbit of the satellite, the sensor is operating in the visible region using reflected sunlight from the earth horizon. During the relatively small time period of the orbit when the sun is behind the earth and it is not possible to operate the sensor in the visible region, precise attitude information is generated by earth radiance balance operating in the IR region. The sensor therefore exhibits the known advantages and accuracy of operation in the visible region for a major portion of an orbit of a satellite, but also maintains attitude control of the satellite during a relatively small portion of the orbit when operation in the visible region is not possible.