Leonid meteor storm and satellite operators

Scientists announce plan to guide satellite operators through meteor storm

Toronto, October 7, 1998 -- A team of Canadian scientists working with the
Centre for Research in Earth and Space Technology (CRESTech) outlined today
a global operation aimed at safeguarding the world's 600-plus satellites as
they head into the first serious meteor threat of the modern space age on
November 17, 1998.

Though the risk of damage from the Leonids meteor storm is considered slight,
a number of international satellite operators, including those of the United
States Department of Defence, the European Space Agency and the Canadian
Space Agency, are working with CRESTech to reduce the odds of impact from the
natural space debris forming the comet trail into which Earth will soon pass.

The Leonids are a swarm of metoroids that intercept Earth's orbit to some
degree every year, usually with little more fanfare than a spectacular night
of watching shooting stars. This year, however, the storm will reach levels
not seen in over thirty years as Earth travels directly into a path of
interplanetary flotsam flung by the four-kilometer-wide Comet Tempel-Tuttle.

That last peak occurred in 1966, at a time when only a handful of small
scientific satellites were in operation. Currently, there are estimated to
be well over 600 operational satellites in Earth's orbit, transmitting
signals 24 hours a day for services such as search-and-rescue, entertainment
broadcasts, telecommunications, as well as the global-positioning system (GPS)
used by commerce, transportation industries and military forces, among others.

"In the last 30 years, people in technologically advanced countries have
developed a strong dependence on a wide variety of satellite services,"
explains Peter Brown, the University of Western Ontario astronomer leading
the CRESTech science team. "Unfortunately, if even one satellite was disabled
during the storm, it may not only be a multi-million dollar disaster for its
owners but may disrupt services for up to millions of clients."

Peter Brown is organizing the Canadian science team providing the hurricane-
style forecast of the shower's activities to satellite operators around the
world during the peak night. Clients include the United States Space Command,
the European Space Agency, the Canadian Space Agency, Canada's Department of
National Defence and several other government and commercial organizations.

For more information, please contact:

Andre Bellefeuille
CRESTech Communications Manager
Office: (416) 665-5464, Cell phone: (416) 707-9120
email: andre@admin.crestech.ca

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Backgrounder

CRESTech Observation Campaign for the Leonid Meteor Storm 1998

Statement of Problem

Many scientists believe that between 1998-2002 there may be a large,
transitory increase in the meteoroid hazard in the near-Earth space
environment resulting from the Leonid meteor shower. The Leonid stream,
which emanates from the constellation of Leo and orbits around the Sun, has a
33-year travel cycle. It peaks over a three-to-five year time span matching
the period during which the parent comet (Comet Tempel-Tuttle) travels closest
to the Earth. Historically, there have been observations of over 40 visible
meteors per second to ground observer during the climax of these storms. This
peak period is normally preceded by a few years of build-up, during which an
indication of potential activity can be recorded from the ground. This
increase in activity is roughly 10,000 times the norm and results in an
accumulation equal to that of several years regular activity in our skies.

There is a general consensus within the scientific community that some
enhanced activity will be realized due to the next shower, however useful
predictions are not possible due to limited historic data. During the last
major meteor storm, in 1966, satellites were much smaller and less numerous
than today. Today there are estimated to be between 600 and 750 operational
satellites in Earth's orbit. While many space-faring nations, predominantly
the United States, have devoted considerable resources to measuring and
understanding "space weather" phenomena caused by solar activity and other
aspects of the space environment, meteoroid activity has not figured
prominently in this effort.

The hazards to spacecraft result not only from the large number of meteoroids,
particularly those of smaller masses, but from the high speed of the Leonid
meteoroids (72 kilometres per second). The effects of such impact may range
from infrastructure damage to the more serious threat of electro-static
discharge generated from such an impact. Such charges could interact directly
with a spacecraft's electrical systems and essentially "short-circuit" the
satellite. The latter effect has been proposed as the likely explanation for
the loss of ESA's Olympus telecommunications platform in 1993. All satellites,
both military and civilian, at all orbital altitudes are at risk from this
natural threat.

Extensive work has been performed by the University of Western Ontario in
London, Ontario, under the funding auspices of the Toronto-based Centre for
Research in Earth and Space Technology (CRESTech), to model the physical
processes resulting in the appearance of this storm. This unique model allows
for predictive capabilities so long as appropriate observational data are
available to constrain the initial conditions. However, observational data is
not yet sufficient to provide accurate forecasts of the shower over the next
five years. Observations made in 1997 indicate that, and agree with, the
recent discussions at an American Institute of Aeronautics and
Astronautics/Aerospace Corporation Conference proposing that activity level
may reach as high as 10,000 naked-eye observable meteors per hour.

The International Program

In 1997, the primary participants in the project were NASA, the United States
Air Force (USAF), the Canadian Space Agency (CSA), Canada's Department of
National Defence (DND) and CRESTech. With the increasing awareness of the
Leonid threat, the participants in the 1998 project are the USAF, CSA, DND,
the European Space Agency (ESA), and a major American commercial operator.
There is also identified interest from TEKES (Finland), and the Societé
Europeene des Satellite (SES).

Organization's participating in the operational portion of CRESTech's program
will receive real-time data on the storm's build-up rate, peak and general
activity. It is expected that these data will be used by some satellite
operators to take one of several courses of action in the event that peak
activity reach dangerously high levels. Among those actions are: changing a
spacecraft's attitude (i.e. pointing direction) to avoid being hit in crucial
or delicate areas; powering down an endangered spacecraft so as to avoid a
massive electrical discharge; or riding out the storm with enhanced ground-
station teams in order to react quickly to storm-generated anomalies.

The Observation Campaign

Location: The two sites best suited, and thus chosen, for the campaign have
been determined as south of Ulaan Baator, Mongolia, near the Gobi Desert,
and at the Royal Australian Air Force's Tindal military site in Northern
Australia, just south of Darwin.

Instruments: The 1998 campaign will employ two methods of data collection:
radar and Low-Light-Level Television (LLTV) observations. Both are capable of
measuring the smallest meteoroids (which are the population relevant to the
space hazard) and each can be used to establish their physical parameters.
The Mongolia site will host two LLTV sites (each with approximately five
camera), and the Australian site will host one radar site as well as one
LLTV site (with two cameras).

Science Team: The CRESTech science team includes Dr. Jim Jones, Dr. Alan
Webster, Dr. Kerry Ellis, Dr. Wayne Hocking, Dr. Martin Beech, Dr. Robert
Hawkes, Ms. Margaret Campbell and Mr. Peter Brown, whom acts as the Project
Manager. This represents the largest group of meteor specialists in the world
with a most varied list of strengths. Dr. Hawkes (Mount Allison University,
Sackville, NB) is the world expert in application of video technology to
meteor observations and heads the LLTV component of the program working
along with Ms. Campbell (University of Western Ontario). Drs. Jones, Webster,
Hocking (UWO) and Ellis (CRC Ottawa) are world leaders in meteor radar
systems, observations and analysis. Dr. Beech (University of Regina) and Mr.
Brown (UWO) have studied and adapted models of the stream and liaise with the
satellite community in an effort to understand satellite effects of the storm.
No other single group has the equivalent breadth of scientific expertise in
this field.

For more information, please contact:

Andre Bellefeuille,
CRESTech Communications Manager
Office: (416) 665-5464, Cell phone: (416) 707-9120,
email: andre@admin.crestech.ca


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Andrew Yee
ayee@nova.astro.utoronto.ca