Goddard Space Flight Center, Greenbelt, Maryland 20771 

ENGINEERING COLLOQUIUM 

Monday, May 1, 2000 / 3:30 PM, Building 3 Auditorium 

Edward Belbruno

ABSTRACT -- Over the past two decades a new type of chaotic motion was noticed in celestial mechanics that was little understood. In 1987, the Speaker was able to find a numerical way to estimate this chaos and apply it to finding very low energy pathways that spacecraft can follow, for example from the earth to the moon. This approach, now called Weak Stability Boundary (WSB) theory, was validated by being operationally demonstrated (1991) when it produced a new low energy route to the Moon that enabled the Japanese spacecraft "Hiten" to reach the Moon in October of that year. Since then this approach has evolved considerably and is being used for a number of new missions including Japan's Lunar-A and PLANET B, and ESA's SMART-1. It is also being used in the Europa mission study at JPL and has applications to Mars' missions. An interesting application (with Brian Marsden at Harvard) of WSB theory deals with the subject of resonance jumping comets and Edgeworth-Kuiper belt objects. Also another way of using chaos is the 'invariant manifold' approach to halo orbit station keeping. Use of low energy trajectories in its relevance for orbital placement of future NASA large space telescopes is discussed; and if time permits, some of Dr Belbruno's space related artwork will also be shown.

SPEAKER -- Edward Belbruno received his doctoral degree from NYU's Courant Institute in 1980, specializing in theoretical celestial mechanics, and then went to Boston University as an assistant professor of mathematics. Interested in applying his theoretical ideas to the more applied arena, he went to JPL in 1985 as an orbital analyst working on Galileo, Magellan, Cassini, and other missions. During that time he laid the foundations for the first systematic use of chaos theory to space flight, originally called fuzzy boundary theory, which allowed for the construction of very low energy paths for spacecraft. In 1991 he went to the University of Minnesota where he applied his work to space mission and astronomy studies. He also started a company to market some methods from his work and played a key role in the salvage of the satellite HGS-1 in 1998, for which he shared Aviation Weeks' Laurel award. Now at Princeton University's Mathematics Department, he is involved with JPL leading a project on WSB theory and its applications. He is also an artist with a number of international exhibitions and has an upcoming one at NASA HQ's gallery in Washington DC and maintains a WEB Page at "www.iorbit.com".