The Global Impact of ITAR on the For-Profit and Non-Profit Space Communities

Under the United States Arms Export Control Act, the International Traffic in Arms Regulations (ITAR) control the export of technologies that are specified as defense articles on the United States Munitions List (USML). The Directorate of Defense Trade Controls (DDTC) within the Department of State (DoS) interprets and enforces these regulations in an effort to safeguard national security by denying advanced military technology to potential competitors

HTs as electromagnetic deployment and support structures in spacecraft

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, February 2013.This electronic version was submitted and approved by the author's academic department as part of an electronic thesis pilot project. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from department-submitted PDF version of thesis.Includes bibliographical references (p. 128-130).In this thesis, we investigate a new structural and mechanical technique aimed at reducing the mass and increasing the stowed-to-deployed ratio of spacecraft systems. This technique uses the magnetic fields generated by high-temperature superconductors (HTSs) to support spacecraft structures and deploy them to operational configurations from stowed positions inside a launch vehicle fairing. The chief limiting factor in spacecraft design today is the prohibitively large launch cost per unit mass. Therefore, the reduction of spacecraft mass has been a primary design driver for the last several decades. Traditionally, spacecraft mass reduction occurs through the use of isogrid panels, aluminum or composites, and inflatable beams all reduce the mass of material necessary to build a truss or apply surface forces to a spacecraft structure. We instead look at using electromagnetic body forces generated by HTSs to reduce the need for material, load bearing support, and standoffs on spacecraft by maintaining spacing, stability, and position of elements with respect to one another. The objective of this thesis is to conduct an initial feasibility study for the use of HTS coils as deployment and support elements in spacecraft structures. To accomplish this objective, we have developed the equations of motion for coils responding to electromagnetic forces while under the influence of constraining elements (i.e. tethers and hinged panels) and validated numerical models of these equations against known analytical solutions. By nondimensionalizing the equations of motion, we have been able to reduce our design variable space through the introduction of lumped dimensionless parameters. This enables simpler trade analysis with regards to structure deployment time and equilibrium configuration, the results of which are also presented and discussed. On the basis of these analyses, we provide suggestions for the selection of design values to achieve desired structural characteristics. Finally, we have introduced, and discussed on the basis of our modeling results, the viability of HTS structures in the context of trade analyses. Trades were described at the mission level, the structural subsystem level, and the component level against traditional and more recently developed alternative structural technologies.by Gettliffe, Gwendolyn Vines.S.M

Stability analysis of electromagnetically supported large space structures

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, February 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 246-250).The high cost per unit mass of launch and the fixed envelope of a launch vehicle fairing respectively incentivize the reduction of spacecraft mass and stowed volume, while the performance boosts that come from an increase in spacecraft dimensions incentivize the maximization of spacecraft deployed size. Also, specific missions might benefit from a particular capability that represents a prohibitive addition of mass to the system or which may be performed inefficiently with current technology, and some missions cannot be accomplished without a capability that existing technologies cannot provide. New technologies, especially those that can contribute multiple capabilities that span the purviews of multiple subsystems, have the potential to enhance or even enable certain mission concepts. This thesis introduces the concept of an electromagnetic subsystem which can provide both structural and ancillary capabilities to a large spacecraft, due to the tendency of two powered coils to exert forces and torques on one another, as well as several missions that would benefit from such a subsystem and in the process help to mature the technology. As with any new technology, risks and challenges are identified as well as other enabling technologies which must be developed in parallel to make an electromagnetic subsystem possible. One major risk comes from the fact that the only stable configuration of two magnets is collocated and attracting at the origin. In repulsion, magnets are fundamentally unstable because they either diverge or rotate such that they attract and converge to the origin. Elastic hardware is added to the system to provide restorative forces and torques, but instability of the system remains a concern. In this work, a validated methodology is developed for identifying pseudo-passive equilibria and classifying them as statically and dynamically stable or unstable and is applied to a series of electromagnetic structures of increasing realism and degrees of freedom to show that stable configurations can exist with appropriate boundary conditions. The methodology is later applied to a variety of systems, including a larger structure with more coils and connective hardware with different properties, to observe how stability conditions change with changes in assumptions or system size.by Gwendolyn Vines Gettliffe.Ph. D