Feasibility Study of a Satellite Solar Power Station

A feasibility study of a satellite solar power station (SSPS) was conducted to: (1) explore how an SSPS could be flown and controlled in orbit; (2) determine the techniques needed to avoid radio frequency interference (RFI); and (3) determine the key environmental, technological, and economic issues involved. Structural and dynamic analyses of the SSPS structure were performed, and deflections and internal member loads were determined. Desirable material characteristics were assessed and technology developments identified. Flight control performance of the SSPS baseline design was evaluated and parametric sizing studies were performed. The study of RFI avoidance techniques covered (1) optimization of the microwave transmission system; (2) device design and expected RFI; and (3) SSPS RFI effects. The identification of key issues involved (1) microwave generation, transmissions, and rectification and solar energy conversion; (2) environmental-ecological impact and biological effects; and (3) economic issues, i.e., costs and benefits associated with the SSPS. The feasibility of the SSPS based on the parameters of the study was established

Accelerometer calibration for NASA\u27s magnetospheric multiscale mission spacecraft

This thesis presents several methods for the on-board and/or ground-based calibration of accelerometers for the spacecraft (s/c) of the NASA Magnetospheric Multi-Scale (MMS) Mission during mission operation. A lumped bias is estimated to correct for the total effect of the MMS accelerometer sensor bias, orthogonal misalignment and the shift in the s/c\u27s center of mass. Various estimation techniques are evaluated and compared, including both dynamically driven real-time filters/observers and post processing batch algorithms. Both methods are shown to accurately determine lumped bias, so long as the s/c inertia tensor is well known. If, however, there is any uncertainty in the inertia tensor, only post processing methods yield accurate lumped bias estimates. Analytical simulations show that these methods are able to correct accelerometer readings to within 1 micro-g of true acceleration. Preliminary experimental verification also shows proof of concept

An attitude determination and control system for small satellites

textA flexible, robust attitude determination and control (ADC) system is presented for small satellite platforms. Using commercial-off-the-shelf sensors, reaction wheels, and magnetorquers which fit within the 3U CubeSat form factor, the system delivers arc-minute pointing precision. The ADC system includes a multiplicative extended Kalman filter for attitude determination and a slew rate controller that acquires a view of the Sun for navigation purposes. A pointing system is developed that includes a choice of two pointing controllers -- a proportional derivative controller and a nonlinear sliding mode controller. This system can reorient the spacecraft to satisfy a variety of mission objectives, but it does not enforce attitude constraints. A constrained attitude guidance system that can enforce an arbitrary set of attitude constraints is then proposed as an improvement upon the unconstrained pointing system. The momentum stored by the reaction wheels is managed using magnetorquers to prevent wheel saturation. The system was thoroughly tested in realistic software- and hardware-in-the-loop simulations that included environmental disturbances, parameter uncertainty, actuator dynamics, and sensor bias and noise.Aerospace Engineerin

1999 Flight Mechanics Symposium

This conference publication includes papers and abstracts presented at the Flight Mechanics Symposium held on May 18-20, 1999. Sponsored by the Guidance, Navigation and Control Center of Goddard Space Flight Center, this symposium featured technical papers on a wide range of issues related to orbit-attitude prediction, determination, and control; attitude sensor calibration; attitude determination error analysis; attitude dynamics; and orbit decay and maneuver strategy. Government, industry, and the academic community participated in the preparation and presentation of these papers

Development of novel satellite attitude determination and control algorithms based on telemetry data from an Earth satellite

All spacecraft missions require accurate knowledge of attitude, which is derived from on-board sensors using attitude determination algorithms. The increasing demands for attitude accuracy, high performance and low cost spacecraft are driving designers to change from available attitude determination methods to those that are more robust and accurate. However, the cost, the processor workload and the time-constraints in spacecraft development and deployment projects curtail the opportunity for developing new on-board attitude determination methods, especially with regards to the development of more precise sensors. Therefore, it is always desired to achieve the required attitude accuracy with the existing set of on-board sensors, but using effective attitude determination methods and sensor fusion algorithms. Developing such algorithms starts on the ground and is subject to verification and tuning with real experimental data from telemetry. Moreover, the on-ground mission control center has to evaluate the attitude accuracy, calibrate sensors and performance. Motivated by these needs, the main objective of this thesis is to develop novel attitude determination algorithms combining several sensors and attitude estimation methods for Ground-Based Attitude Estimation (GBAE) with telemetry data. The GBAE formulation will be based on a guaranteed ellipsoidal state estimation for acquisition mode and a modified Kalman filter for pointing mode, to provide optimal attitude estimates of the spacecraft. The GBAE has to be evaluated both in the simulation environment and in the flight environment. In the simulation environment, the evaluation of the GBAE rests on the availability of an accurate dynamical model for the spacecraft. However, spacecraft dynamics are complex with multiple modes of operation. Moreover, the nonlinearities in the actual system make the spacecraft dynamics more complex. This motivates the use of switching between a global nonlinear controller for acquisition mode and a local linear controller for pointing mode, which can guarantee performance and is less computationally intensive for implementation in an on-board microprocessor. In this thesis, novel attitude determination and control algorithms are evaluated in the flight environment for a case study in collaboration with the Canadian Space Agency for the SCISAT-1 satellite

An autonomous orbit transfer controller for the NASA Magnetospheric MultiScale satellite

With the ever more demanding goals of space exploration and research comes the need for more complex mission planning. Part of this complexity manifests itself in a satellite\u27s orbit specifications. An increasing number of explorer missions call for a group of satellites to maneuver while arranged in a tightly controlled formation, or constellation. In order to maintain these constellations at immense distances from Earth, engineers must rely on feedback systems within the satellites\u27 hardware. Controllers are created to manipulate the actuators, such as thrusters, and are therefore responsible for the economical use of fuel; overusing fuel can reduce a satellite\u27s useful lifetime. It is necessary to achieve all controller demands while monitoring fuel consumption when developing a system such as the one presented by this thesis. This thesis presents a detailed method of obtaining a simplified model of a spin-stabilized spacecraft and its environment, including relevant uncertainties, disturbances and sensor models. This thesis shows through rigorous simulations that it is feasible to control orbit maneuvers of spin-stabilized spacecraft to very strict specifications, despite the inclusion of sensor noise, thruster disturbance and bias, and nutation effects

Mercury/Gemini program design survey. NASA/ERC design criteria program stability, guidance and control

Mercury/Gemini stability, guidance, and control equipment design criteri

Project STRATUM

Design, instrumentation, operation, and control of Project STRATUM satellite /Stratified Thermosphere Research at University of Michigan

The Apollo spacecraft: A chronology. Volume 2: 8 November 1962 - 30 September 1964

A chronology of the Apollo spacecraft development and production program is presented. The subjects discussed are: (1) defining contractural relations, (2) developing hardware distinctions, and (3) developing software ground rules. Illustrations, drawings, and photographs are used extensively to supplement the technical writing. Descriptions of life support systems, communication equipment, propulsion systems, control devices, and spacecraft components are provided

Conceptual mechanization studies for a horizon definition spacecraft attitude control subsystem, phase A, part II, 10 October 1966 - 29 May 1967

Attitude control subsystem for spin stabilized spacecraft for mapping earths infrared horizon radiance profiles in 15 micron carbon dioxide absorption ban