LETTERS TO THE EDITORS
Low-Energy Pathways in Space
To the Editors:
The article by Shane Ross ("The Interplanetary Transport
Network," May-June) made little mention of the origins of this
field of study. Much of its foundation lies in my own work from
1986. In 1991 I provided the first demonstration of low-energy
pathways within this network to rescue a failed Japanese lunar
mission and transport their spacecraft, Hiten, to the Moon. This
exciting rescue inspired much of the work Ross described. In 2004
the European Space Agency's SMART 1 spacecraft made use of another
low-energy lunar route from my work.
An even more obvious omission concerns the description of the
resonance motion of Comet Oterma. This follows directly from the
paper "Resonance Hopping in Comets,” published by Brian
Marsden of the Smithsonian Astrophysical Observatory and myself in
the April 1997 issue of the Astronomical Journal.
Department of Astrophysical
Dr. Ross responds:
I apologize to Dr. Belbruno that the article omitted his and Dr.
Marsden's work. I agree that Dr. Belbruno's fascinating work on the
Japanese Hiten mission helped establish low-fuel trajectories as a
reality. My article was not intended as a comprehensive historical
survey, and space limitations meant that many contributors to the
field unfortunately had to be left unmentioned.
My hope was to convey the excitement of recent ideas in celestial
mechanics and their deep mathematical relationship to other fields,
such as chemistry, fluid mechanics and galactic dynamics. I imagine
that ideas about low-fuel pathways will gain more attention in
coming years and it is important to have a correct historical
perspective on their development as well as their connections with