http://www.eurekalert.org/pub_releases/2006-01/nyao-nbr010506.php
Public release date: 5-Jan-2006
Contact: Jennifer Tang
[EMAIL PROTECTED]
2128380230 x257
New York Academy of Sciences
New book reveals how engineers saved Hughes satellite from disaster on
Christmas Day 1997
First published account of 1997 spaceflight sets record straight
A former Hughes Spacecraft Company engineer and part of a team which
rescued a satellite that went astray on Christmas Day 1997 with a daring
maneuver that sent it to the moon and back, gives the first complete
description of the rescue in New Trends in Astrodynamics and
Applications, Volume 1065 of the Annals of the New York Academy of
Sciences. The rescue was the first successful attempt to re-route a
commercial satellite into a near geostationary orbit using a "free
return lunar flyby" trajectory, which may someday allow space tourists
to see the moon from its far side.
After launch from Kazakhstan on Christmas day 8 years ago, the Hughes
601HP communications satellite failed to execute its final burn, leaving
it stranded in an unusable elliptical orbit with an orbit plane far from
the equator. "It was a healthy spacecraft in a bad orbit. Mission over,"
commented Cesar Ocampo, who worked for Hughes at the time but is now an
associate professor of aerospace engineering at the University of Texas
at Austin. The craft did not have enough fuel on board to bring it back
into the proper orbit using standard methods, which are analogous to
changing lanes in a traffic circle.
A DARING RESCUE
However, two aerospace engineers outside the company, Edward Belbruno
and Rex Ridenoure, came up with the audacious suggestion that saved the
mission: they suggested saving fuel by diverting the satellite all the
way to the moon and taking advantage of the moon's gravity to bring the
satellite back into a usable orbit. Belbruno is editor of the Annals
volume, is visiting research collaborator at Princeton University, and
president and founder of Innovative Orbital Design, Inc. Currently,
Ridenoure is President and CEO of Ecliptic Enterprises Corporation of
Pasadena, California.
"The suggestion to Hughes from Belbruno and Ridenoure was key," Ocampo
said. "Until then nobody at Hughes had thought of using the moon to
rescue this stranded satellite." The actual route to the moon used was
different than the one suggested by Belbruno and Ridenoure, but the
fundamental idea of having to use the moon's gravity in some capacity
was critical.
A COVER-UP
Ocampo's paper, "Trajectory Analysis for the Lunar Flyby Rescue of
AsiaSat-3/HGS-1" is the first published account of the rescue, which
received a great deal of attention in the press at the time of the
rescue, between April and July 1998. However, publicity from Hughes
Spacecraft never acknowledged the contributions of either Ridenoure or
Belbruno, a grievous omission that the article seeks to redress.
After the mission plan had been devised and its execution initiated,
Ocampo was ordered to seize further communication with Belbruno and
Ridenoure and was barred from participating in any external
communication activities and presentations made to the public and other
organizations.
"This cover up represents a major injustice by a prominent corporation
of an historical event, and is a blemish on ethical behavior in the
aerospace community," says Belbruno.
NEW USES FOR THE LUNAR FLYBY TRAJECTORY CONCEPT
The rescue mission was the first commercial operation in the vicinity
the moon. The free return lunar flyby trajectory concept had also been
used as contingency trajectories by NASA's Apollo spacecraft. Ocampo
predicts it will soon become more common. The free return lunar fly-by
trajectory is especially beneficial in terms of fuel for geostationary
bound spacecraft launched from high latitude space ports. Last August,
the private space tourism firm Space Adventures, Inc., said it will be
offering individuals the chance to fly around the moon and back by the
year 2010 using a similar maneuver.
(www.spaceadventures.com/media/releases/2005-08/284)
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