Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 968 for “"spacecraft"”.
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Spacecraft-ns3: Spacecraft Discrete-Event Network Simulation
… constellations of satellites and research into spacecraft autonomy and disaggregation becomes more prevalent, it will be increasingly important to design effective communication procedures between satellites to efficiently share resources and avoid collisions. Though there have been several …
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Maneuver analysis for spinning thrusting spacecraft and spinning tethered spacecraft
<p>During axial thrusting of a spin-stabilized spacecraft undergoing orbital injections or control maneuvers, misalignments and center-of-mass offset create undesired body-fixed torques. The effects of the body-fixed torques, which in turn cause velocity pointing errors, can be reduced by ramping …
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A new spacecraft autopilot.
Thesis. 1976. M.S. cn--Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics.
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Spacecraft Attitude Tracking Control
The problem of reorienting a spacecraft to acquire a moving target is investigated. The spacecraft is modeled as a rigid body with N axisymmetric wheels controlled by axial torques, and the kinematics are represented by Modified Rodriques Parameters. The trajectory, denoted the reference …
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Spacecraft and Propulsion Technician Error
<p>Commercial aviation and commercial space similarly launch, fly, and land passenger vehicles. Unlike aviation, the U.S. government has not established maintenance policies for commercial space. This study conducted a mixed methods review of 610 U.S. space launches from 1984 through 2011, which …
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Assessing the fractionated spacecraft concept
In the traditional approach, spacecraft are tailored to each mission and are associated with high risks and costs and long cycles. Moreover, once launched, their flexibility remains limited. The concept of spacecraft fractionation could enable manufacturers and users to decrease these risks and …
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Spacecraft Trajectory Optimization Suite (STOpS): Optimization of Multiple Gravity Assist Spacecraft Trajectories Using Modern Optimization Techniques
<p>In trajectory optimization, a common objective is to minimize propellant mass via multiple gravity assist maneuvers (MGAs). Some computer programs have been developed to analyze MGA trajectories. One of these programs, Parallel Global Multiobjective Optimization (PaGMO), uses an interesting …
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Spacecraft Trajectory Optimization Suite (STOPS): Optimization of Low-Thrust Interplanetary Spacecraft Trajectories Using Modern Optimization Techniques
<p>The work presented here is a continuation of Spacecraft Trajectory Optimization Suite (STOpS), a master’s thesis written by Timothy Fitzgerald at California Polytechnic State University, San Luis Obispo. Low-thrust spacecraft engines are becoming much more common due to their high efficiency, …
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Bandwidth-limited robust nonlinear spacecraft control
Robust large-angle spacecraft pointing and tracking by Variable Structure Control (VSC) are developed. The control of multiaxial attitude dynamics is a highly nonlinear problem, which can be resolved by exact feedback linearization with respect to attitude variables. This requires exact …
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Spaceborne centrifugal relays for spacecraft propulsion
Acceleration using centrifugal relays is a recently discovered method for the acceleration of spaceborne payloads to high velocity at high thrust. Centrifugal relays are moving rotors which progressively accelerate reaction mass to higher velocities. One important engineering problem consists of …
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Fuel efficient attitude control of spacecraft
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1979.
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Design of an optical interferometer spacecraft
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1992.
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Spacecraft Orbiting and Uncertainty - Planning Surveillance
Scheduling of the Space Surveillance Network (SSN) is a crucial operation for the maintenance of safety and operations in Earth’s orbit. However, the capabilities of the SSN are limited and the number of objects that are being tracked is increasing with every year. This work proposes harnessing …
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Spacecraft formation flight exploiting potential fields
… system have led to the proposal of several multi-spacecraft missions by both NASA and DoD. One such benefit is the reconfigurability of these multi-spacecraft systems. This ultimately led to additional requirements being levied onto these missions, such as the general astrophysical imaging …
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A software architecture for autonomous spacecraft
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.
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Formationkeeping of spacecraft via differential drag
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1986.
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Control of spacecraft in proximity orbits
Formation flying of spacecraft and autonomous rendezvous and docking of spacecraft are two missions in which satellites operate in close proximity and their relative trajectories are critically important. Both classes of missions rely on accurate dynamics models for fuel minimization and observance …
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Maneuver and control of flexible spacecraft
… The equations of motion for a three-dimensional spacecraft undergoing large rigid-body maneuvers are derived. The elastic motions are assumed to remain in the linear range. A method of substructure synthesis is presented which spatially discretizes the equations of motion. A perturbation approach …
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Optimal large angle spacecraft rotational maneuvers
… problems associated with optimal large angle spacecraft rotational maneuvers. Both rigid and flexible body dynamical models for these vehicles are considered. Three relaxation/analytic continuation methods are developed for iteratively solving the two-point-boundary value problem which results …
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