Abstract: In one embodiment of the disclosure, a computing system includes a processor and a computer readable medium. The computer readable medium is operable to, when executed on the processor, determine an estimated trajectory of a satellite using a sequential mode of operation, perform a thruster burn, receive a data point from an uplink/downlink facility, determine an estimated trajectory and an estimated thruster performance of the satellite based upon the received data point. If the trajectory error is above a specified threshold level, repeat receiving an updated data point from the uplink/downlink facility, determining an updated estimated trajectory and an updated estimated thruster performance of the satellite based upon the updated data point, and determining an updated trajectory error based upon the updated data point.

Abstract: A ship includes a star tracker mounted on a platform stabilized in ENU by the inertial navigation system (INS). The line-of-sight (LOS) of the star tracker is directed toward two separated stars, and the LOS difference angles are noted. The angles are processed to generate vector triads representing geodetic (ephemeris) and navigation system attitude. The triads are processed to generate a coordinate transformation matrix. The transformation matrix is separated into systematic error and reference attitude error. The reference attitude error is summed with the inertial navigation system attitude to generate corrected ENU attitude. The corrected attitude is used as a reference for shipboard sensors, to reduce errors when the sensor data is linked to other platforms.

Abstract: Various embodiments of the present invention are directed to precision control system for spacecraft gimbaled payloads. Embodiments of the invention provide an innovative technique of calibrating gimbals disturbances to directly canceling gimbal control disturbances. Such a calibration system includes a receiver for receiving telemetry data for pointing a payload, a processor for calculating a disturbance parameter vector for a gimbal disturbance model with the telemetry data and a transmitter for transmitting the disturbance parameter vector to compensate for pointing error when applied in pointing the payload. The gimbal disturbance model comprises a harness stiffness term, a disturbance harmonics term and at least one friction hysteresis term. The telemetry data may be time matched prior to calculating the disturbance parameter vector.

Abstract: A method and apparatus for controlling a gimbaled platform (108). The method comprises the steps of computing an acquisition phase gimbal angle rate command ?cmd—Acq (530) from a measured LOS angle error ??LOS (520) for an initial control period T while computing an estimated LOS angle rate {circumflex over (?)}LOS (524), computing a tracking phase gimbal angle rate command ?cmd—Trk (532) using a controller (512) having an output initialized with the estimated LOS angle rate {circumflex over (?)}LOS (524), and commanding the gimballed platform (108) according to an angle rate command ?cmd (522), wherein the angle rate command ?cmd (522) is the acquisition phase angle rate command ?cmd—Acq (530) during the initial control period T and the tracking phase gimbal angle rate command ?cmd—Trk (532) after the initial control period T.

Abstract: Provided is a satellite control system based on integrated satellite operation data and a method thereof. The satellite control system includes: a satellite operation data schema editing means for creating a document type definition file and defining a schema; a mission planning means for creating a mission timeline and recording the mission timeline; a command planning means for converting a task into telecommands and recording the telecommand; a command preparing means for creating a telecommand procedure and recording the telecommand procedure; a command transmitting means for creating a telecommand code, transmitting the telecommand code to a satellite and recording the telecommand code; a command verifying means for receiving telemetry data and recording a telecommand verification result; and a performance result reporting means for creating a mission performance result and recording the mission performance result.

Abstract: Provided are an automatic operation system for automating satellite control operation, a method thereof, and an automatic satellite ground control system using the same. The object of the present research is to provide an automatic operation system that can reduce operation manpower and cost by automatically operating an entire satellite ground control system, which requires a plurality of operators to be properly operated, all the times, a method thereof, and an automatic satellite ground control system using the same. The satellite ground control system of the present research includes: a mission timeline receiving unit, an operation procedure editing unit, an operation procedure analyzing and code transforming unit, an operation procedure executing unit, a subsystem process state monitoring unit, and an access managing unit for providing interface with each of the subsystems.

Abstract: Apparatus, Systems, and Methods are provided for controlling motion of a spacecraft. One apparatus includes a non-contacting actuator and a passive mechanical system coupled in parallel with one another. A system includes a payload, a bus, and a hybrid actuator including a non-contacting actuator and a passive mechanical system coupled in parallel, and coupled between the bus and the payload. The system also includes an inertial actuator configured to maneuver the bus to maintain a relative position and/or attitude of the bus with respect to the payload. One method includes receiving a signal instructing a first controller to change the position and/or attitude of a payload and utilizing a hybrid system to change the position and/or attitude of the payload. The method also includes receiving the signal at a second controller and utilizing a system to change a position and/or attitude of the bus independent of the payload.

Abstract: This invention provide systems and methods for cockpit flight crew preflight planning and subsequent, systematic recall and execution of procedures, ground/inflight navigation, and communications using portable electronic data storage and display devices. A capability is provided within a portable electronic data storage and display device to replace and replicate the typical preflight planning methodology of the individual flight crew member to facilitate execution of a procedures, navigation and communications plan from preflight to postflight. A user may create a usable subset of the potentially thousands of available pages of data or data reference pages stored in the portable electronic data storage and display device, organizing the perhaps 100 or less individual pages of data, static or interactive, desired for a specific leg of the flight in order that required information is immediately available in an expected order of need.

Abstract: Disclosed is an attitude change control system that is designed to efficiently output a torque for attitude change of a space craft using CMGs and realizes a real time CMG driving rule. A CMG gimbal steering law 15 generates target profiles for setting angle and angular velocity for each gimbal by applying an anisotropic weighted gradient method based upon the necessary torque calculated by a feed back controller 13 and a feed forward controller 14 from the angle and angular velocity in the target direction from the attitude navigator 12 and the current angle and angular velocity of the space craft estimated by the attitude estimator 11 as well as the current condition of each gimbal from the CMG 40, thereby controlling the CMG 40 for changing the attitude of the space craft dynamics 50 to the target direction.

Abstract: An N-Tiered enterprise and/or N-Tiered Web-based enterprise system and methods for managing, monitoring, coordinating the procedures of and optionally controlling a fleet of geosynchronous satellites through a distributed network such as the Internet. The system and associated object oriented software architecture seamlessly supports monitoring and analyzing real-time, near real-time, historical/playback, simulated and archived satellite telemetry as well as Tracking, Telemetry and Control (TT&C) ground system generated data products such as real-time alerts, archived alerts and ground system server statuses from a group of legacy distributed TT&C wide area network (WAN) ground station systems located around the world.

Abstract: A method of determining the attitude of a spinning spacecraft is provided. The method includes stabilizing the spacecraft, initializing the attitude of the spacecraft using star tracker data, and estimating the attitude of the spacecraft.

Abstract: An improved approach to satellite-based navigation (e.g., GPS) is provided. In one embodiment, a method includes determining a nominal orbital path of a navigation satellite. The method also includes transmitting ephemeris data corresponding to the nominal orbital path from the navigation satellite to a plurality of navigation devices. The method further includes determining an actual orbital path of the navigation satellite locally at the navigation satellite. In addition, the method includes determining a deviation between the actual orbital path and the nominal orbital path locally at the navigation satellite. The method also includes autonomously adjusting the actual orbital path locally at the navigation satellite to reduce the deviation between the actual orbital path and the nominal orbital path.

Abstract: A system, method and computer program product are disclosed for receiving data from a satellite radio network in accordance with an embodiment of the present invention. In accordance with an embodiment of the present invention, a datagram broadcast via a satellite radio network is received utilizing a receiver. The datagram includes broadcast identifier information that identifies a segment of receivers in the satellite radio network to which the datagram is directed. Utilizing the broadcast identifier information, a determination is made as to whether the recipient receiver is a member of the identified segment of receivers to which the datagram is directed. If the recipient receiver is determined to be a member of the identified segment of receivers to which the datagram is directed, then the datagram is processed.

Abstract: Systems and methods for automatically switching to a track view mode on a vertical view display. The system determines aircraft position relative to a leg of a flight plan and switches display mode for a navigation vertical display to track view mode, if the display mode is in a plan view mode and if the determined relative position is greater than a threshold distance.

Abstract: An improved approach to satellite-based navigation (e.g., GPS) is provided. In one embodiment, a method includes receiving a first set of tracking information. A nominal orbital path for the navigation satellite is determined using the first set of tracking information. Ephemeris data corresponding to the nominal orbital path is computed and uploaded to the navigation satellite. Long-term navigation information corresponding to the nominal orbital path is transmitted to a communication system for broadcast to a plurality of navigation devices. A second set of tracking information is received, an orbital path of the navigation satellite using the second set of tracking information is predicted, and a difference between the predicted orbital path and the nominal orbital path is determined. Commands configured to instruct the navigation satellite to adjust an actual orbital path of the navigation satellite to substantially conform to the nominal orbital path are uploaded to the navigation satellite.

Abstract: An aeronautical navigation plotting instrument is provided that includes a plotting frame and a compass rose attached to the plotting frame. The compass rose includes angular markings incrementally disposed thereon about a center of the compass for defining the angular orientation of the compass. A longitudinal slot is aligned with the center of the compass rose and extends through the plotting frame to define an opening for receiving a writing instrument. A plurality of first radial openings extends through the plotting frame to allow a writing instrument to extend therethrough. Each first radial opening is incrementally spaced from an originating opening in the plotting frame to form a plurality of incrementally spaced radial distances from the originating opening.

Abstract: A vehicle having a first transponder circuit generating an over-the-air transmission signal and a reference signal is disclosed. The vehicle also has a receiver circuit that receives the over-the-air transmission signal. The vehicle also has an integrity-checking circuit receiving an integrity signal from the receiver circuit. The integrity signal is based on the over-the-air transmission signal received by the receiver. The integrity-checking circuit also receives the reference signal from the first transponder circuit. The integrity-checking circuit determines the integrity of the over-the-air transmission signal.

Abstract: Momentum control is maintained in a geosynchronous orbiting spacecraft that uses a plurality of reaction wheel assemblies and a plurality of magnetic torquers to control the spacecraft momentum, each orbit of the spacecraft being comprised of a set of time steps, by determining a current momentum error for a current time step of a current orbit by adding a system momentum change determined for an immediately preceding orbit to an average system momentum determined for the immediately preceding orbit, and then subtracting a magnetic control torque momentum change determined for the immediately preceding orbit, determining a current duty cycle for each of the magnetic torquers based on the current momentum error and on a torque value applied by each magnetic torquer at each time step of the immediately preceding orbit, and commanding each magnetic torquer to operate at the current time step in accordance with its respective determined current duty cycle, wherein the magnetic torquers apply a magnetic momentum c

Abstract: Provided are a method and apparatus for compensating an attitude of an inertial navigation system and a method and apparatus for calculating a position of the inertial navigation system using the same. The method of compensating an attitude of the inertial navigation system includes sensing movement of the system and outputting information for stoppage time periods and a movement time period of the system; receiving angular velocity information of the system during every time period and calculating a first attitude of the system using the angular velocity information; receiving gravity direction information of the system during the stoppage time periods, calculating a second attitude of the system using the gravity direction information, and calculating an attitude error of the system during every time period using the first attitude and the second attitude; and compensating the attitude error for the first attitude.

Abstract: A system for providing attitude and antenna steering for a spacecraft is disclosed. The spacecraft has a number of reaction wheels and a number of antennas. The system includes control logic configured to: determine a beta angle, the beta angle being the angle between a sun vector and an orbit plane of the spacecraft, and alternately engage either a first mode or a second mode to provide attitude and antenna steering based on the beta angle.

Abstract: A safe interactive navigation apparatus and method allows the crew of an aircraft to prepare and follow a safe flight plan without relying on instrument flying infrastructure. An aircraft navigation assistance method calculates a continuous, three-dimensional projected path on board the aircraft as a function of data related to the route and characteristics of the aircraft.

Abstract: Embodiments are disclosed for a vehicle control system and related sub-components that together provide an operator with a plurality of specific modes of operation, wherein various modes of operation incorporate different levels of autonomous control. Through a control user interface, an operator can move between certain modes of control even after vehicle deployment. Specialized autopilot system components and methods are employed to ensure smooth transitions between control modes. Empowered by the multi-modal control system, an operator can even manage multiple vehicles simultaneously.

Abstract: A method and apparatus for controlling a plurality of solar panels of a spacecraft is described. The method comprises the steps of providing a first step command to a first solar panel, and providing a second step command to a second solar panel at a time of a transient zero-crossing of a dynamic response of the spacecraft body to the first step command, wherein the second solar panel is disposed on an opposite side of the spacecraft from the first solar panel. The apparatus comprises a processor; a first solar panel driver, communicatively coupled to the processor, for providing a first step command to a first solar panel, and a second solar panel driver, communicatively coupled to the processor, for providing a second step command to a second solar panel at a time of a transient zero-crossing of a dynamic response of the spacecraft body to the first step command.

Abstract: Systems and methods for interplanetary space navigation are provided. In one embodiment, a system for navigating a spacecraft in outer space is provided. The system comprises means for broadcasting navigation signals to a spacecraft traveling in outer space, each navigation signal comprising a spread-spectrum signal that includes information on the location of the means for broadcasting navigation signals, the time the navigation signal was transmitted and a reference frame identifier; means for receiving the navigation signals transmitted from the means for broadcasting navigation signals; and means for determining one or more ranges and delta-ranges between the means for receiving and the means for broadcasting based on the navigation signals using time-of-arrival (TOA) techniques; means for calculating a position of the spacecraft in space based on the one or more ranges; and means for calculating a velocity of the spacecraft in space based on the one or more delta-ranges.

Abstract: A method for modeling a structure deployed on a spacecraft. The method includes determining a geometric shape that resembles the structure in a fully deployed configuration; generating time functions for a change in shape of at least one structural component of the structure, the change in shape occurring as the structure expands into the fully deployed configuration; and calculating mass properties of the geometric shape as a function of the time functions.

Abstract: An algorithm uses offline metrology to control a process by passing information from an outer control loop to an inner control loop, extended Kalman filter estimator. The inner control loop operates online, and the outer control loop operates asynchronously with respect to the inner control loop. The online control loop is updated for each subsequent process. The offline metrology is optionally updated for each subsequent process.

Abstract: A method for minimizing the amount of propellant required to be carried onboard the satellites of an Earth orbiting satellite constellation to maintain the minimum angle of elevation between a selected geographical area of the Earth and at least one satellite of the constellation during the life of the constellation includes establishing an optimal initial inclination and RAAN of each satellite of the constellation. The method enables the satellites of the constellation to carry additional hardware and other payload mass, or alternatively, the design life of the constellation to be increased.

Abstract: A system and method are disclosed for tracking a position of an orbital body relative to a planetary body. A processor (602) with memory (603) stores reference data associated with the planetary body. A single sensor (601) coupled to the processor, generates a scene frame (212) of a portion of the planetary body. A reference frame corresponding to the scene frame is retrieve from the memory. An image or one or more features of the scene frame is compared with a corresponding image or features associated with the reference frame. An attitude and/or an ephemeris of the orbital body is estimated by solving an equation set in open form or closed form based on the comparison and inputs such as rotation rate value and a linear velocity value associated with the orbital body.

Abstract: A system and method for providing autonomous control of unmanned aerial vehicles (UAVs) is disclosed. The system includes a ground station in communication with an unmanned aerial vehicle. The method for providing autonomous control of a UAV includes methods for processing communications between the ground station and UAV. The method also includes procedures for processing commands from the ground station. Also included in the method is a process for estimating the attitude of the UAV and autonomously maintaining its altitude within a desired threshold. The method also includes a process for autonomously orbiting about a specified point in space. Combined with these processes, the method also includes a process for an autonomous takeoff and landing of the UAV.

Abstract: A system and method to enhance attitude estimation for transfer orbit maneuvers of a spinning satellite includes a transfer orbit earth sensor that can receive and convert an infrared radiance to an analog signal. The analog signal is provided to a hardware chord processor and an analog-to-digital converter. The hardware chord processor determines an earth chord length based on the analog signal. The analog signal is sampled in the analog-to-digital converter to provide a digital signal to a digital earth sensor pre-processor, which reshapes the digital signal to provide a pre-processed signal having nearly distinct peaks. A software chord processor is provided with the pre-processed signal. The software chord processor locates the peaks in the pre-processed signal and determines an earth chord length.

Abstract: The present invention provides a network data recording system particularly adapted for use in transportation systems. Cameras, microphones and a variety of sensors and existing vehicle systems are networked to a central controller, which receives and processes audiovisual and other data from the cameras and sensors. Raw and processed information is stored in a removable memory which may be mirrored to a fixed local memory. The fixed local memory can also be used to store programs and other system data. The controller may be ruggedized to meet disaster recovery requirements. Control panels can be placed throughout the vehicle for use by the crew to monitor conditions and respond to them. Information can be sent to a ground station, and the ground station may also exhibit control over the network data recording system. The system is suitable for use in all manner of transportation systems, such as aircraft, trains, and ships.

Abstract: There is provided a method of controlling a power-train of a hybrid electric vehicle comprising an internal combustion engine, a first electric machine directly driven by the internal combustion engine for generating electricity, and a second electric machine driven at least partly with the electricity for driving the vehicle wheel. The method comprises adjusting the speed and adjusting the torque of the internal combustion engine, while substantially maintaining the intake manifold pressure, in response to a change of the desired electricity from the first electric machine. According to the method, the higher engine efficiency can be maintained, because the engine intake manifold pressure is maintained during adjusting the engine speed and torque. The engine speed may be adjusted corresponding to a speed of the first electric machine with higher efficiency and the desired output electricity. Therefore, both the engine and the first electric machine may achieve the respective higher efficiencies.

Abstract: A method and apparatus for reducing centroiding error of a star sensor having a plurality of pixels is disclosed. The method comprises the steps of computing a star sensor angular slew rate of ? pixels per star sensor integration period ?, collecting star sensor data while slewing the star sensor according to the selected star sensor angular slew rate ?, and filtering the collected star sensor data according to a frequency determined by the selected star sensor angular slew rate.

Abstract: An apparatus for estimating attitude using an inertia measuring apparatus comprising: a Kalman filter 3 adapted to receive a quantity of state ?(t) from the inertia measuring apparatus 1, input the quantity of state into a predetermined system equation and a predetermined observation equation and execute time update processing and observation update processing with regard to the system equation and the observation equation; a processing section 4 adapted to generate an estimated value of a time differentiation of a modified Rodrigues parameter ?(t) based upon an output of the Kalman filter; an integral processing section 5 adapted to generate an estimated value of the modified Rodrigues parameter based upon an output of the processing section; a system propagation matrix generating section 6 adapted to update an observation sensitivity matrix based upon an initial value being given beforehand and an output of the integral processing section and supply the updated output to the Kalman filter; a transformed mat

Abstract: The present method provides a method for avoiding singularities in the movement of CMGs in an array of CMGs in a spacecraft. In a first step, a torque command representing a desired torque to produce an attitude adjustment for the spacecraft is received. Next, a range-space gimbal rate required to produce the desired torque based on the desired torque and a Jacobian matrix is calculated. Then, a null-space gimbal rate that assists in the avoidance of singularities is calculated. The total gimbal rate command is determined by summing the range-space gimbal rate and the null-space gimbal rate. Then, the total gimbal rate command is provided to the CMGs to produce the total gimbal rate.

Abstract: A flight control system for preventing an aircraft colliding with designated man-made structures in which the geographical position of the aircraft is determined and then compared with predetermined geographical boundaries that represent excluded zones; these zones being defined around the man-made structures; where the system, as appropriate, overrides a normal flight control system (such as a fly-by-wire flight system) to alter the course of the aircraft to avoid all excluded zones, irrespective of any pilot commands.

Abstract: A method of showing approval or disapproval of an item overheard on an audio system. The method includes sending an item via radio waves to an audio system, listening to the item on the audio system and activating a button to indicate approval or disapproval of the item.

Abstract: A device for indicating at least a first vibration level VIB1 derived from a first acceleration signal ?1 includes: first analysis element FT1 for resolving the first acceleration signal ?1 into a plurality of axial analysis signals ?1i each occupying an identified frequency band Bi; a first memory RM1 having recorded therein a plurality of axial weighting coefficients KAi, each corresponding to one of the identified frequency bands Bi; and a first control circuit CC for summing the pth powers of the axial analysis signals ?1i weighted by the axial weighting coefficients KAi, thereby producing the first vibration level VIB1.

Abstract: Methods and apparatus are provided for a traffic warning system (TWS) for light aircraft. The TWS comprises a processor coupled to a transceiver, adapted to measure signal strength and send/receive messages containing station ID and preferably altitude and position data. Memory, display and various flight data instruments, such as GPS, altimeter, etc., are also coupled to the processor. The transceiver-processor automatically identifies TWS equipped aircraft within range using an ad-hoc network and exchanges ID and position information. The processor determines range from signal strength and/or received position information and, given enough data, determines direction, altitude, speed, etc., of the other aircraft, which it presents to the pilot. These values and their rate of change are compared to stored alarm thresholds, and the pilot is warned when another aircraft triggers the threshold. Evasive action is recommended where possible.

Abstract: A spacecraft attitude control system and method in which an attitude controller is configured for sensing three-dimensional attitude of the spacecraft, and producing torque signals for stabilizing the spacecraft in a prescribed attitude in space. At least four mutually skew reaction wheels are rotated in response to the torque control signals for storing three-dimensional angular momentum, and speeds of rotation of the wheels are measured. A reaction wheel speed control processor, responsive to reaction wheel torque and speed for producing reaction wheel spin control signals, implements an infinity-norm algorithm for causing the nullspace components of wheel speed to re-distribute a desired three-dimensional stabilizing momentum of the spacecraft in such a manner that the maximum speeds of rotation of all the reaction wheels is minimized. As a result, periods between successive momentum dumping maneuvers are prolonged to the maximum possible.

Abstract: A system and method for navigation utilizing sources of pulsed celestial radiation are provided. A spacecraft, satellite, or other vehicle (12) has a pulse sensor (22) mounted thereto for detecting signal pulses (14) generated by a plurality of pulsars or other celestial objects (16). The detected signal pulses (14) are synchronously averaged at the known period of the pulsar or other celestial object (16) with respect to a timer (24). Timer (24) measures the pulse time of arrival at the pulse sensor (22) by comparing the pulse signal (14) with a pulse shape template (52), and a processing means (30) calculates the offset time between the measured pulse time of arrival at sensor (22) with a calculated pulse time of arrival at the solar system barycenter (SSBC).

Abstract: The invention concerns a method for preventing airplanes from impermissibly approaching defendable ground objects, the method suggests that a defendable ground object is assigned a virtual prohibited zone spatially surrounding it, with the outer boundary of such zone being provided with a sufficient horizontal minimum distance from the ground object and a vertical minimum distance determining a given minimum crossing altitude, that the prohibited zone is assigned a virtual correction zone laterally surrounding it whose outer boundary has a horizontal minimum distance from the outer boundary of the prohibited zone in any case sufficient for any forced deviation corrections and an altitude equal to that of the prohibited zone; that the correction zone is assigned a virtual alarm zone spatially surrounding it whose outer boundary has a horizontal minimum distance from the outer boundary of the correction zone in any case sufficient for manual deviation corrections; that the geographical data of the outer boundar

Abstract: This invention relates to a method and apparatus for assessing quality of service for communication networks. More particularly, the invention is directed to assessing quality of service in circuit and packet switched networks by way of a computer simulation. Preferably, the information necessary to conduct the assessment activity is available via the internet from a web server that also compiles statistical data on the resultant quality of service assessments.

Abstract: An improved satellite communication device and system are provided. The satellite communication device uses yaw or roll-yaw steering to linearize angular track of uplink cells; one-dimensional linear “ratcheting” in an uplink antenna to maintain resource allocation of uplink cells along antenna columns; phased-array downlink antennas which can track earth-fixed downlink cells while compensating for the yaw (or roll-yaw) satellite steering; and variable rate TDMA service among downlink cells in a footprint. As a result, system overhead for performing new resource allocations between satellite handovers is minimized, thereby reducing resource management and increasing system capacity. Flexible bandwidth/capacity assignment of both uplink and downlink resources to earth locations via linear cell ratcheting, uplink RF peaking switch, and data-driven variable-TDMA downlink phased-arrays, is provided.

Abstract: In order to control the attitude of a satellite having at least four gyroscopic actuators with respective spinners mounted on gimbals steerable about axes parallel to one or the other of only two different directions that are fixed relative to the satellite, the attitude of the satellite is measured using sensors on board the satellite, the control torque required to perform an attitude-changing maneuver is calculated, local linearization calculation is performed based on pseudo-inversion of the Jacobean matrix of the function associating the orientations of the actuator gimbals with the total angular momentum of the cluster in order to determine a new gimbal orientation, and precession speeds of at least one of the gimbals of the actuators are controlled to deliver the control torque for reaching the desired configuration.

Abstract: A method and apparatus for estimating spacecraft momentum is disclosed. The method comprises the steps of generating a plurality of spacecraft momentum measurements, fitting the plurality of spacecraft momentum measurements to a parametric model of a spacecraft momentum profile having a time period of tp, determining the momentum of the spacecraft from the parametric model; and generating an estimate of the momentum to be removed from the spacecraft at least in part from the determined momentum of the spacecraft.

Abstract: A method for yaw steering a spacecraft including performing yaw steering of the spacecraft to have a yaw angle (?) for all sun elevation angles (?). The method further including smoothing a yaw steering motion for orbital position parameters (?) where high rotational rates {dot over (?)} and high rotational accelerations {umlaut over (?)} would occur. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

Abstract: A reconfigurable digital processing system for space includes the utilization of field programmable gate arrays utilizing a hardware centric approach to reconfigure software processors in a space vehicle through the reprogramming of multiple FPGAs such that one obtains a power/performance characteristic for signal processing tasks that cannot be achieved simply through the use of off-the-shelf processors. In one embodiment, for damaged or otherwise inoperable signal processors located on a spacecraft, the remaining processors which are undamaged can be reconfigured through changing the machine language and binary to the field programmable gate arrays to change the core processor while at the same time maintaining undamaged components so that the signal processing functions can be restored utilizing a RAM-based FPGA as a signal processor.

Abstract: A closed-loop LRF pointing technology to measure the range of a target satellite from a chaser satellite for rendezvous is provided that includes: LOS angle measurements of the target, a relative navigation Kalman filter, attitude determination of the visible sensor with gyros, star trackers and a Kalman filter, pointing and rate commands for tracking the target, and an attitude controller. An analytical, steady-state, three-axis, six-state Kalman filter is provided for attitude determination. The system provides improved functionality and precision for relative navigation, attitude determination, pointing, and tracking for rendezvous. Kalman filters are designed for the closed-loop system to allow for pointing the laser rangefinder to a target even if a visible sensor, a laser rangefinder, gyros and a star tracker are misaligned and the LOS angle measurements from the visible sensor are interrupted.

Abstract: A system (18) includes: a) A vehicle (12) includes an attitude or angular velocity control system (38), a plurality of star trackers or star sensors (22) each having a field of view (28); b) a memory (30) having a star catalog (32), an allocated area for a star pair catalog (58) and a reference table (56) stored therein; and c) a processor (24) coupled to the attitude or angular velocity control system (38), the star trackers or star sensors (22), and the memory (30). The processor (24) populates the star pair catalog (58), using the method described herein. The processor (24) then periodically determines the vehicle inertial attitude or angular velocity or sensor alignment, based, in part, on the star pair catalog (58) and reference table (56). The novel ability of the software to autonomously populate the star pair catalog (58) allows users to avoid uploading a large amount of data, and the problems associated with such an upload.