Friday, May 4, 2007, 11am - 12pm, MDEA

Space Power and Propulsion for the 21^st Century

Ray Sedwick

Principal Research Scientist and Associate Director

Space Systems Laboratory

Massachusetts Institute of Technology

Abstract

As we enter the 21^st century, awareness and interest in space exploration have increased, even though the resources made available for university research in this area have not.  Eventually, the focus on the technology of the here-and-now will re-broaden with the realization that there is a continual need for the development and integration of ‘next generation’ technologies.  In the meantime, it is important to maintain momentum in the development of these advanced concepts. In this talk, three such potential technologies in the area of space power and propulsion for the 21^st century are discussed.

The first of these systems, referred to as Electromagnetic Formation Flight (EMFF), is a technology in which the relative degrees of freedom of a formation of spacecraft are controlled via a combination of electromagnetic coils and reaction wheels on each vehicle.  This form of control trades well against existing propellant-based methods of propulsion, however because it uses no consumables has the potential to extend mission lifetimes indefinitely.  Two implementations of this technology, one using high temperature superconducting (HTS) wire, and one using conventional conducting wire are presented.

The second technology is a gas core nuclear thermal propulsion system utilizing vortex containment of fuel.  The advantage of a gas core system is that core temperatures are in theory not limited by the melting or boiling points of the fissile fuel, allowing for much higher specific impulse and more efficient propellant usage than solid or liquid core systems.  However, isolation of the core from the solid walls that confine it is a major hurdle.  Magnetohydrodynamically (MHD) driven vortices are capable of such isolation and a system design based on this principle is described. 

The final technology is a fusion based space power generation system based on the principle of inertial electrostatic confinement (IEC).  A concept that has been around since the beginning of fusion research, an IEC based fusion system has the potential to be significantly less massive than a magnetically or inertially confined system.  While the fusion gain of laboratory IEC systems has historically been comparatively low, a new approach is presented that provides evidence that an IEC fusion system might be made to operate above breakeven. Shorter-term spin-off technologies such as a portable source of neutrons or high-energy protons for medical isotope generation are discussed.
 

Biographical sketch

Dr. Ray Sedwick is a Principal Research Scientist and Associate Director of the (other) Space Systems Laboratory in the MIT Department of Aeronautics and Astronautics.  He received his BS in Aerospace Engineering from Penn State University, and his SM and PhD in Aeronautics and Astronautics from MIT.  As a researcher in the MIT SSL he has been involved in numerous research areas, spanning space-based sensing and interferometry, imaging systems and spaceflight mechanics, however his primary area of interest is space propulsion.  Dr. Sedwick has conducted research in many areas of space propulsion, ranging from performance analyses of micropropulsion systems for formation flight, invention and development of Electromagnetic Formation Flight technology, and improvements in Inertial Electrostatic Confinement for fusion power production.  He has recently published several papers on the fluid dynamics, thermochemistry and power conversion associated with gas core fission propulsion, and maintains a broad interest in all areas of space propulsion systems.