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Chapter
9: Cycle 23
"During 1999 and 2000, we really expect some wild
rides. We really don't know what effects we are going to see."[JoAnn
Joselyn, Cycle 23 Project]
The instruments on board NASA's Solar and Heliospheric
Observatory (SOHO) were routinely keeping watch on the Sun on April
7, 1997, when the EIT camera picked up a typical garden-variety, class-C6
solar flare in progress. Scientists back on earth watched while a shock
wave from the flare passed through the local gases in the solar corona
like the waves from a pebble dropped into a pond. It was a beautiful
event to watch, looking for all the world like some artful animation,
rather than the awesome detonation that it actually was. In minutes,
a ring of compressed gases had spread to engulf a patch of the Sun as
big as the earth. Radiation sensors onboard the geosynchronous GOES
weather satellites detected a rain of flare particles minutes later.
Meanwhile, radio telescopes began to detect the tell-tail radio waves
from a Type II burst on the Sun. The CME, in its haste to leave the
Sun, had shocked and compressed solar plasma ahead of it, snowplowing
them into walls of stripped atoms and magnetic fields that emitted powerful
blasts of radio waves. At 15:00 UT, as the shock wave spent itself,
the LASCO instrument witnessed a major CME grow to the size of the Sun
and larger.
Three days later on April 11 at 00:00 UT, the WIND
and SOHO satellites, parked one million miles from the Earth towards
the Sun, started to feel the direct impacts of energetic particles from
the CME. The faint signals from the compressed interplanetary wind had
already been sensed a few hours earlier. Ground-based magnetometer readings
from CANOPUS, the Canadian magnetic observatory network, started to
feel major changes in the Earth's field heralding a Large Storm Commencement
at 3:00 UT. Meanwhile, the POLAR satellite had already seen auroras
begin to grow on the dayside of the Earth at 19:50 UT. By 22:26 UT,
intense nighttime aurora could be seen in New Hampshire and Massachusetts
as the aurora slid past the US-Canada border and plunged into the Lower-48.
Many amateur photographers reveled in spectacular opportunities to capture
on film both the dazzling auroral curtains, and the history-making comet
Hale-Bopp.
The great series of domino events tracked by NASA
satellites, literally from cradle-to-grave, prompted scientists to release
a press announcement on April 8th that predicted the real meat of this
CME would harmlessly pass about a few million miles below the plane
of the Earth's orbit. At best it would be a glancing blow, and most
probably not a direct hit. As seen from the Sun, hitting the Earth is
not exactly a turkey shoot even with a million-mile-wide bullet. The
magnetosphere of the Earth extends over 100,000 miles from the center
of the Earth, and has about the same apparent size as a dime held at
30 feet. Even though CMEs are huge, the Earth is such a small target,
you really have to get CME and solar flares pointed right at the Earth
before there's a good chance of any physical contact happening.
The news media were especially fascinated by this
cosmic salvo. The spectacular satellite images of its genesis millions
of miles away, made the CME near miss almost irrelevant. It really didn't
matter if the storm would only be a glancing blow this time. April 10th
turned out to be a big news day for this cosmic non-event, with nearly
all of the major national and international newspapers carrying some
kind of story about it. Some reporters, unfortunately, rushed into press
with rather sensational stories such as Matthew Wald's article in the
New York Times, "Storm on Sun Is Viewed From Spacecraft; First
detailed look at solar event that could effect life on earth", which
was datelined April 9th and published on April 10, 1997. Meanwhile,
CNN and Yahoo!News, reassuringly reported in their on-line news services
that "Solar Flare small after all, poses little damage" (CNN)
and "Solar Storm's Full Force to Miss Earth" (Yahoo). Even the
Boston Globe reported "Not much flare to this solar event,
experts say". NBC, CBS and CNN News, carried interviews with George
Withbroe, Chief of the NASA Office of Space Science, and Nicola Fox,
a scientist at NASA's Goddard Space Flight Center who coordinates the
Global Geospace Science program. Nearly every news report mentioned
possible technology impacts should the CME actually hit the Earth, including
electrical blackouts and satellite outages.
Our Sun traces a dependable path across our skies
every day, yet only very recently have we discovered that it has its
share of stormy days. For the last three centuries, solar activity levels
have come and gone in a roughly 11-year pulse beat that we have actually
grown to expect. Even our biosphere shows the unmistakable traces of
these cycles resonating in everything from carbon-14 abundances in tree
rings, to global precipitation patterns and coral layering. Our eyes
never see the Sun brighten or dim, nor are we even remotely aware that
the Sun cycles back and forth from stormy to quiescent. It is a small
cause, which manages to have a big effect on the hidden aspects of our
environment. The fulcrum lies somewhere in the dark spaces between the
solar photosphere and our own murky comprehension of the Sun-Earth connection.
Just knowing about the solar cycle has been a promising
first step in figuring out what the Sun will do over the long haul,
even though the average person on the street is hardly aware that these
cycles happen. The solar cycle, however, is a poor barometer of what
we should expect the Sun to do for us tomorrow, and that's what is most
interesting to satellite owners, astronauts and electrical utility managers.
Within each regular cycle, the Sun is actually rather temperamental.
It hurls flares and billion-ton clouds at us almost at random, dissipating
with each blast, any sense of predictability.
By the time you read this chapter, one thing is certain:
you will be near the end of this book, but only about half way through
the current sunspot cycle - Cycle 23. If you were a solar physicist,
a satellite owner, or a General in the Armed Forces, the question that
you would be asking by now is, "Just how bad will this cycle
be?" The answer depends on what you are concerned about. If you are
worried about your communications or espionage satellite, "Will a flare
erupt in the next day or so, and cause a satellite anomaly?" If you
are trying to plan for next-years budget, "Are we in for a bad solar
'summer' with many more opportunities for weekly flares and technological
difficulties?" Either way, it is hard to know with any certainty. If
a flare as bad as the Cycle 20, Apollo 17 near miss arrives during ISS
construction, astronauts could be seriously affected. We could also
be treated to a Quebec-style blackout like we were in Cycle 22, which
could cost several billion dollars to recover from. So we do what has
become a reflex reaction to uncertainty in the second half of the 20th
century:
We set up a committee to study the problem.
For much of this century, groups of scientists have
gathered together to try to guess how bad the next cycle is going to
be. With so many expensive undertakings on the agenda for this cycle,
NASA and NOAA continued this long tradition in 1996 by setting up the
Solar Cycle 23 Project. The first thing this panel did was to
contact the rest of the astronomical community and invite everyone to
send in what they thought Cycle 23 might be like. The catch was that
they also had to describe in detail, what method they used to make the
prediction. There was no reason for the panel to try to re-invent the
wheel in solar activity forecasting, when the community they represented
had already worked this particular problem for decades. The panel's
request brought to their table no fewer than 28 separate methods; by
some estimates, nearly as many methods as there are researchers in this
particular field. Only a few of the methods, by the way, had anything
to do with the popular image of counting sunspots. Some of them tracked
the rise and fall of geomagnetic storms here on Earth, others followed
the total amount of radio power from the Sun at a wavelength of 10.6
centimeters. Ultimately, like an ancient traveler in Italy, all roads
lead to Rome.
The biggest problem everyone had to face was that,
by all accounts, the Sun was smack in the middle of the activity minimum
between Cycles 22 and 23. Getting a reliable prediction for Cycle 23,
without even a year's worth of data on the new cycle, wasn't going to
be easy at all. Scientists are not at all new to this kind of a situation.
They usually have to face frustration, and uncertainty, every day as
they conduct their research. When you work with limited information,
a common circumstance in space research, you often have to bridge the
gaps by using past experience, and the collective knowledge of physical
science, as a guide.
So the panel weighed the uncertainties in each of
the 28 methods, and how well they had anticipated previous cycles. In
the end, they were prepared to say that the time of the maximum for
Cycle 23 would be around March 2000. They also hedged their bet by offering
the alternative prospect that solar maximum could happen as late as
June 2001, or even as early as the summer of 1999. The March 2000 prediction,
however, was close to the average made by most of the methods, so that's
the one the panel favored. The panel also predicted how high the activity
levels would rise, which is considerably more difficult to anticipate.
Their prognosis was that Cycle 23 probably wouldn't be as bad as Cycle
19, but it might be at least as bad as Cycle 21 with its roughly 150
spots near maximum. Incidentally, the panel didn't consider the possibility
that this 'millennial' sunspot cycle might be the Sun's last one. This
is not such a far-fetched possibility at all. Before 1700, telescopic
observers of the Sun detected few sunspots. Their meticulous observations
provided no hint to later generations of astronomers of any periodic
rises and falls. There was a chance that we could wake up in 1997 or
1998 with no new cycle anywhere in sight.
Once the new cycle began, the panel's predictions
for the minimum, average, and maximum Cycle 23 activity curves soon
had data starting to crawl up as though the Sun were navigating a three-lane
highway. It was pretty obvious by December 1999 that the predicted trends
were running a bit higher than expected. Monthly sunspot averages were
just below the curve the Panel had proffered as their minimum activity
prediction. Rather than the high-speed lane, the Sun slowed to the breakdown
lane to get through the turn of the Millennium.
So far, the ascent up the jagged curve of Cycle 23
has been quite a wild ride. The years 1997 and 1998 had their share
of spectacular solar eruptions and auroral displays. On the other hand,
1999 was uneventful for the Earth despite the fact that over 100 CMEs
were being ejected by the Sun each month.. The good news was that Cycle
23 was not going to be a major storm period this time; at least not
like the levels reached in Cycles 21 and 22. When you factor-in the
details of individual flares and CMEs, the dossier for Cycle 23 has
turned out to be dramatically more complicated than what a simple count
of sunspots would tell you. It is the day-to-day engagements with solar
flare and CME 'bullets' that can cause harm.
As scientists settled in to watch their data eagerly
anticipating new breakthroughs in solar research, the news media also
developed an interest in keeping watch on the Sun. In fact, Cycle 23
has been hawkishly watched in a way that no other previous cycles have
been. Armed with the latest spectacular imagery from NASA's satellites,
it has been much easier to anticipate when bad things might be brewing,
because you can actually see them happen days in advance. Even
school children can visit NASA web sites to view images of today's solar
surface and make their own predictions. Before the first spots of this
cycle started to appear, Time magazine announced in 1996 that,
"Cosmic Storms Coming". A year later, Space News also cautioned
their readers that "U.S. Scientists Warn of Rise in Solar Flares". NASA
held a formal press conference at the Jet Propulsion Laboratory on February
15, 1996 which was heralded as a 'Briefing Directly Linking Solar Storms
to Disruptions on Earth". The briefing topic was about 70 years too
late given all of the impacts we had already endured during the 20th
Century.
Cycle 23 officially began in September, 1996 when
the first spots of the new polarity cycle were spotted, followed by
a month when not a single new spot was seen. As the first spots of this
cycle began to slowly appear at high solar latitudes. Like solders nervously
sitting in a foxhole waiting for the first rounds to fly, engineers
and scientists braced themselves for the inevitable solar onslaught.
They didn't have long to wait. Barely three months after the start of
the new cycle, the first major solar event leaped out at the Earth and,
by many accounts, claimed its first technological casualty: one of the
key satellites of our communication infrastructure - Telstar 401.
This was followed by the April 10th near-miss of the
Earth by another CME which was highly publicized. NASA scientists, armed
with their new satellite technology, were now 'two-for-two' in having
predicted the course of major solar storm events during the new sunspot
cycle.
A month after the April 10th near-miss, Space News,
a much-read weekly newspaper of the space community, carried a short
article about a major new-generation satellite, which had encountered
space weather difficulties at about the time this solar event reached
Earth's orbit. The Tempo-2 satellite, equipped with the latest in high-power,
gallium-arsenide solar arrays lost 15% of its operating power on April
11, and this was directly credited to the solar storm by Loral's Space
Systems Division who manufactured the satellite. In a May 1 statement
from company spokesperson David Benton announced that,
"We have evidence from sensors on the satellites that
there was a space event in the vicinity of the Tempo satellite at the
time of the disturbance."
The Space News article also mentioned that
a spokesman for the satellite owner, TCI Satellite Entertainment, took
a far more cautious position for why the satellite lost some of its
operating power. Unlike Loral who credited the space weather event with
the problem, TCI announced that they were "unclear whether the storm
had actually exceeded the levels the satellite was built to withstand,
or if the satellite simply had a flaw". Compared to the murky causes
surrounding the Telstar 401 outage, this level of candor by Loral was
refreshingly to the point, even though the satellite owner preferred
a more guarded opinion. It would, of course, be the satellite owner
that would seek insurance payments, not the satellite manufacturer.
In a replay of the Telstar 401 settlement, TCI filed a claim for $20
million.
Far from being just another satellite stamped from
a tried-and-true design, Tempo-2 was supposed to be the vanguard of
a whole new fleet of high-capacity communications satellites. Communication
satellites had evolved from humble 10-watt 'small reptiles' to leviathan
multi-kilowatt 'dinosaurs' driven by the relentless evolutionary pressure
of consumer demand. To generate the 10s of kilowatts of power needed
to operate dozens of transponders and other high-end equipment, engineers
had been forced to create lighter-weight, and higher-power solar cells.
The current darling for this new technology is based on semiconductor
compounds of gallium and germanium, rather than the common silicon cell
materials. The new cells would be wired to produce 60 volts per module
to keep the weight and size of the solar panels within the limits set
by the cost of the satellite. One of these panels, incidentally, could
comfortably supply the needs of a medium-sized house. But the Tempo-2
failure uncovered a potentially fatal problem with these new panels.
They were susceptible to energetic particle impacts, which caused miniature
lightning bolts to flare-up and short circuit sections of the panels.
Engineers would certainly have to go back to the drawing board to fix
this problem, because these satellites were to be the wave of the future.
Compared to winter and spring, the rest of the summer
of 1997 unfolded in comparative calm. Although there is no public data
on anomalies experienced by commercial or military satellites at this
time, deteriorating space weather conditions by the end of September
were openly cited as the cause of a Japanese satellite glitch. On September
20, 1997, the $474 million Adeos research satellite, launched by Japan
a year earlier, began to malfunction. According to a report in Space
News,
"...Cosmic rays were found to have damaged the main
on-board computer, which caused it to shut down all non-essential systems,
including the sensors, forcing scientists to reprogram its software"
There were no obvious geomagnetic storms in progress
near the Earth on this particular day according to the Canadian CANOPUS
magnetic observatory network, so whatever space event had taken its
toll on Adeos, it had managed to skirt the sparse network of instruments
available to record it. When you have one trillion cubic miles to cover,
there are plenty of opportunities for a handful of instruments to be
in the wrong place to see anything. In many ways, it's like trying to
keep track of the weather in Tokyo from monitoring stations in Stockholm,
Manila and Rio de Janero.
Close on the heals of the Adeos satellite problem,
the Sun decided to get back into the act of terrorizing the Earth. The
SOHO satellite witnessed two major CME events on September 24 and September
27. The events were echoed in the data returned by the ACE satellite
on September 30th as the CME plasma rushed by the satellite at nearly
one million miles per hour. CNN News and the Reuters News
Service reported that India had lost an advanced communications
satellite, INSAT-2D on October 2, 1997 because of a power failure. The
satellite, launched June 4, 1997, carried 24 transponders for relaying
Indian telephone and television traffic. The satellite's problems seem
to have started on, or before, October 1 when it lost Earth-lock briefly,
shortly after the September 27th CME had passed the Earth on September
30th. One of its predecessors, INDSAT-1C launched on July 21, 1988,
fell silent under similar circumstances in 1989. According to a summary
for INSAT-1C in Janes Space Directory "..a power system failure
from a solar array isolation diode short" caused the satellite to
lose half of its capacity. On November 22, 1989 the satellite lost its
Earth lock and was abandoned at a cost of $70 million.
For INSAT-2D, ACE magnetometer data showed a sharp
rise in solar wind strength on October 1 at 0000 UT followed by a persistent
plateau of magnetic field intensity lasting a full day before subsiding
again. The Earth-orbiting GEOTAIL satellite also noted a sharp change
in the local energetic particle conditions as well as geomagnetic field
strength. All of these are consistent with the arrival of the September
27 CME around October 1 at the time the INSAT-2D began having its problems.
The Insat-1C, by the way, failed on November 22, 1989
during the last of a series of major solar and geomagnetic storm events
of this memorable year. These storms caused major increases in energetic
protons at energies above 10 MeV, between October 19 through November
6, rivaling all of the events in solar cycle 22 taken together. On November
15th another powerful solar blast was detected on ground-level neutron
monitors, and at the end of November another major solar flare, rich
in high-energy protons, was recorded. According to space researcher
Joe Allen at the NOAA National Geophysical Data Center, each of these
events caused power panel degradation in a variety of satellites. Some
lost 5-7 years of usable lifetime. Others suffered a variety of glitches
and operational anomalies.
Thanksgiving, Christmas, and New Years passed uneventfully,
at least by any outward appearance here on Earth. Meanwhile, 93 million
miles away, the Sun continued to steadily ratchet-up its tempo of delivering
CMEs to nearly 50 per month. On April 15, 1998 one of these events produced
some unsettled geomagnetic conditions here at the Earth. A few days
later on April 20 at 10:21 UT, the strongest solar proton flare recorded
since 1994 made a stellar appearance. It was an M1-class eruption; among
the literally hand-full of severe flares the Sun likes to cook-up each
cycle. In keeping with the unpredictable nature of these disturbances,
even though the solar storm involved both a CME and a powerful solar
flare, geomagnetic conditions here at the Earth were barely affected.
A week later, a second round of storms commenced with a major outpouring
of pyrotechnic events. This was, however, just a warm-up pitch for what
would turn out to be one the largest storms in 1998.
A series of low-level, X-class flares and multiple
CMEs were expelled between April 29 and May 2. The outfall finally started
to reach the Earth around May 2-3 causing a severe geomagnetic storm.
Only three times before, during the January 1997, April 1997 and November
1997 encounters, had scientists gone so far as to provide formal press
briefings for impending calamities. Like earthquake forecasting, it
is better to miss a few quietly, than announce false positives. But
the conditions, this time, seemed to warrant some kind of official comment
just in case the storms might grow to become something more provocative
than the topic of a scientific research paper. So far, the scientists
seemed to be batting 100. The last three press releases had confirmed
that scientists could anticipate the likely geospace impact of some
solar storms. This new one would extend this winning streak to four.
On May 4 at 00:18 EDT a strong GIC affected the northeast
United States as capacitor banks were tripped. This caused transformer
saturation affecting a major electrical substation in New Brunswick,
and caused voltage regulation problems throughout Maine. Minutes later
in New York state, voltages also started to drop in the eastern part
of the state. The Nova Scotia electrical company measured 70 ampere
GICs in one of its transformers. A day later, routine testing of a transformer
in the Hudson Valley indicated insulation damage and a temperature spike
of several hundred degrees Celsius. According to John Kappenman at MetaTech
Corporation, the Hudson Valley electrical utility recorded this problem
as due to 'undetermined causes'.
Satellite owners had also experienced their own spate
of problems, many of them fatal, between April and July of 1998. Apparently
the first satellite to succumb to these conditions, and publicly acknowledged,
was the German research satellite Equator-S. On May 1 the satellite
owned by the Max Planck Institute lost its backup processor. According
to an announcement by the Institute at the official web site for this
satellite,
"If a latch-up caused by penetrating particle radiation
was the cause, there is hope that it may heal itself upon the next eclipse
because of the complete temporary switch-off of the electrical system"
After no mention of any satellite problems among the
70+ satellites now in orbit since their first launch on May 5, 1997,
Space News reported four Iridium satellites launched prior to
May 1 had already failed. By May 8 this number jumped to five, and by
July 23 there were now seven Iridium satellites that had failed or were
ailing. One of the failures apparently had something to do with a satellite
separation problem during a Delta 2 launch. The Iridium satellite network
has been built with the assumption that about six satellites per year
will have to be replaced. 1998 easily reached that mark. Although there
is no hard evidence to suggest the rest of the Iridium satellites failed
because of the major space weather events of April-May, the timing of
the press releases seems more than coincidental. So many in-orbit failures
for a satellite system barely a year old, led to a predictable loss
of confidence from stockholders. Investors voted with their feet by
dropping the stock price for Iridium LLC $10 to 46 3/4 a share. Motorola's
spokesman Robert Edwards noted, optimistically, in a Space News
article that Motorola does not believe there is a common link behind
the seven failures so far, although two of the satellites had their
functions restored and are now working normally. According to International
Space Industry Report, an unnamed 'industry sources' confided that,
"These are no doubt reaction wheel failures; at least seven wheels
have mission-threatening problems or failures". Meanwhile, another
'Big LEO' satellite program, Teledesic, was having its own problems
before it even got a chance to put any of its 288 satellites in orbit.
On May 7, the Teledesic 1 (T1) experimental satellite was no longer
operating as planned. No details were given either of the cause of the
malfunction, the systems involved, or the time when the satellite failed.
The most spectacular outage since Telstar 401 rocked
the satellite community on May 19th when the $165 million, Galaxy IV
satellite suddenly went for an unplanned stroll and mispointed its antenna.
By some accounts, as many as 45 million pagers in North America instantly
went silent. This outage was followed on June 13th by the loss of the
primary control processor on the Galaxy VII, and an identical problem
with the DBS-1 satellite on July 4. PanAmSat Corporation, the owner
of the three Hughes model HS-601 satellites, was never able to identify
a clear cause for these failures. International Space Industry Report
carried a headline "Hughes Hit Hard by Satellite Failures".
'The failures have sent Hughes scrambling for an explanation,
and left industry analysts wondering whether other Hughes-built satellites
of the same family may be subject to similar problems"
Space physicist Dan Baker and his colleagues at the
University of Colorado, however, uncovered satellite evidence for a
very disruptive space environment spawned by the April-May solar activity
episode. There was a major NASA, POLAR satellite anomaly on May 6, and
more than a dozen anomalies plagued Japan's Global Meterological Satellite
system between May 4-7. What was interesting about the data presented
by Dan Baker, was that it showed how active the geospace environment
could remain even several weeks after a major CME impact. Could the
outage of the Japanese ETS-7 satellite 2-3 weeks after the November
7, 1997 storm fall into the same category of delayed satellite impacts?
The March 22, 1991 flare was so powerful, and rich in energetic particles,
that it actually caused a new radiation belt to form around the Earth.
The Combined Release and Radiation Effects Satellite (CRRES), Geostationary
Operational Environmental Satellite (GOES-6) and the Geostationary Meteorological
Satellite (GMS-4) had no problems detecting this belt. The belt was
even seen by dosimeters on board the STS-40, STS-42 Space Shuttle missions,
and MIR space station up to 10 months later. There were no space weather
events at the time of the Galaxy VII outage, but ACE and WIND sensors
detected a very strong disturbance in the solar wind between July 1-3.
The more scientists study the response of the geospace environment,
the more they seem to discover it is a morass of delayed effects and
complex phenomena that don't always deliver their worst punches after
an obvious, well-telegraphed, encounter with the Sun.
As summer declined into the Labor Day hiatus, on August
27 1998 a severe geomagnetic storm, and yet another press release, was
triggered by the arrival of a CME event aimed directly at us. At 3:00
EST on August 26, plasma from the CME finally arrived at the Earth and
began to trigger a major geomagnetic response, recorded by the 13 magnetic
observatories operated by the USGS as far south as Hawaii. The US Geological
Service, which seldom wades into the Space Weather arena in such a public
manner, thought enough of this event to issue its own press release
"USGS Reports Geomagnetic Storm in Progress". Spectacular aurora, meanwhile,
were observed as far south as North Dakota. Sometime during, or before,
the week of September 9, another Iridium satellite suffered a malfunction.
September 23 saw yet another CME provide a replay
of the severe 'Labor Day Storm'. Again, dazzling green and red aurora
reaching as high as 1/2 way up the northern horizon corusced in North
Dakota and Canada. A major M2-class proton flare added to this chorus
a week later on September 30.
The rest of 1998 passed uneventfully with the Sun
continuing to produce between 40-60 CMEs per month. The SOHO satellite,
which had experienced a commanding problem on June 24, had by now recovered
all of its scientific functions, and its handlers were learning how
to operate it with out the benefit of its gyros. Other satellite handlers
were not having such a happy conclusion to their labors, though. On
December 20, 1998 the NEAR spacecraft was just beginning a crucial 20-minute
burn of its thruster to ease it gently into orbit around the asteroid
Eros. The thrusters were turned on by the satellite following a pre-recorded
set of instructions, but suddenly the spacecraft aborted its firing.
For 27 hours, the satellite refused to speak to Earth until ground controllers
finally got a weak reply from it. They quickly uploaded commands for
NEAR to take as many pictures as it could as it hurled past Eros. Why
had the carefully planned rocket firing gone awry in mid-execution?
By June 1999 engineers had run numerous tests using identical computers
and software, but were unable to reproduce the glitch. A similar thruster
firing had to be commanded exactly on January 3, 1999 so that NEAR could
return for a second orbit insertion try in February 14, 2000. This time
there was no glitch.
Not all mysterious problems in space necessarily have
a space weather explanation as their root cause. Sometimes it really
can be a finicky line of computer code or an outright hardware failure.
These explanations usually become obvious after investigators carefully
sift through the satellite's housekeeping data which, like an airliner's
'black box' describe what the satellite was doing prior to the mishap.
Neither of these explanations seemed to apply to the NEAR spacecraft
since its second thruster firing went-off without a hitch. But many
problems can have something to do with local environmental factors,
especially when we voyage into interplanetary space and confront the
unknown. On September 29, 1989 a category X-9.8 solar flare was recorded
on the backside of the Sun, and not visible from the Earth. The Magellan
spacecraft enroute to Venus experienced power panel and star tracker
upsets from the portion of the solar flare that had passed its way.
ACE satellite observations of the solar wind show that it was far from
calm around the time of the NEAR mishap. Even so, the specific environment
in the vicinity of NEAR cannot be estimated from only ACE satellite
data measured at one point in a different part of the solar system.
There were five significant solar proton flares recorded
in January, April and June 1999, but none strong enough to warrant much
alarm near Earth orbit. The only significant satellite event to happen
during the first half of 1999 occurred on March 12 when GE Americom's
GE-3 satellite suffered an anomaly affecting its station-keeping ability,
causing the satellite to spin out of control. The satellite had been
placed into service September 1997 and its transponders carried a number
of feeds for CNN, PBS and Turner Classic Movies. Readings from the ACE
and WIND satellites at the time showed that between March 10-13th, there
was a space weather event in the solar wind. Particle densities and
magnetic field strengths increased 5-20 times above typical baseline
levels before and after this event. There were no geomagnetic storms
in progress on this date, however.
Once again, India's satellite weather service was
brought low by the failure of another of their satellites, this time
Insat-2E. In a Space News report on November 29, mention was
made that this satellite had started to have problems 'about two months
ago'. Despite simulation studies which showed that the undisclosed problem
might be rectified, they finally went public with the problem and announced
that the satellite was being taken out of service. Geomagnetic indicators
provided by the CANOPUS and SESAME magnetometer networks in Canada and
Antarctica showed that mild storm conditions existed around September
23 and 27, and ACE satellite data also showed two large space weather
events at this same time.
The only really severe geomagnetic event in 1999 occurred
on October 22 when conditions were elevated to a Large Storm status
for a single day; the first time since November 1998. There were no
published satellite outages, but John Kappenman, an electrical engineer
with MetaTech Corporation, notes that some North American power utilities
recorded transformer trips on October 23 that could have been related
to this storm.
As you can see from the chronological listing of satellite
outages and anomalies the Table 5 during the first half of Cycle 23,
this cycle has been far from inconsequential. The published satellite
outages, totaling nearly $1 billion so far this cycle, tend to happen
close-by some significant space weather event. The worst of these to
date has been the April-May 1998 storm whose lasting effects seem to
have left in its wake a number of satellite outages and severe operational
anomalies. What is also interesting from this record is that, with over
2000+ communications and military satellites in orbit and operational,
the actual, severe, satellite anomaly count from these storms is so
small. We cannot know if this is simply the result of selective reporting,
but at least for the military satellites, it is obvious that military
secrecy is a powerful inhibitor to announcing these satellite outages.
The list of commercial satellite outages and mission-threatening anomalies
in Table 5 is probably complete, since it is difficult for major communication
satellite lapses to be hidden from the news media when they happen.
This suggests that, in fact, the vast majority of the present commercial
satellites are surprisingly robust in operation through even the most
adverse space weather conditions we have seen since Cycle 23 began.
There are, however, some very obvious and troubling tendencies that
have grown more apparent in these commercial satellite reports.
Rarely do commercial satellite owners give specific
dates and times for the outages, and in the case of Iridium, the specific
satellite designations are even suppressed, as is any public discussion
about the causes of the outages themselves. If this is to be the wave
of the future in commercial satellite reportage, especially from the
Big LEO networks now being planned such as Teledesic, we are in for
a protracted period of confusion about causes and effects. Without specific
dates and reasons for failure, scientists cannot then work through the
research data and identify plausible space weather effects. This also
means that the open investigation of why satellites fail, which could
lead to improvements in satellite design, and improved consumer satisfaction
with satellite services, is all but ended. As Robert Sheldon notes,
"...the official AT&T failure report [about the
Telstar 401] as presented by Dr. Lou Lanzerotti at the Spring AGU Meeting
denied all space weather influence and instead listed three possible
[technological] mechanisms...This denial of space weather influence
at this meeting was met with a murmuring wave of disbelief from the
audience who no doubt had vested interests in space weather".
Moreover, a new factor has begun to enter the equation.
For years, NOAA had kept a master file of reported satellite anomalies
from commercial and military sources. The collection included well over
9000 incidents reported to NOAA's Space Environment Center during previous
decades. This voluntary flow of information dried-up in 1998 as one
customer after another stopped providing these reports. From now on,
access to information about satellite problems during Cycle 23 would
be nearly impossible to obtain for scientific research. More than ever,
examples of satellite problems would have to come from the occasional
reports in the open trade literature, and these would only cover the
most severe, and infrequent, major satellite failures. There would be
no easy record of the far more numerous daily and weekly mishaps, which
had been the pattern implied by the frequency of these anomalies in
the past.
So far, Cycle 23 has brought with it a mixed bag of
problems; the only thing missing is a power blackout. No one really
wants to benefit from the chaos that results from a severe blackout.
Still, NASA space scientists, and NOAA Space Weather Forecasters, would
be silently grateful for a new 'event' that would keep space weather
forecasting in the public and congressional eye. Even engineers for
the electrical power industry bemoan the lack of any significant storms
during the first half of this cycle to trigger a Quebec-style blackout.
Without a large, socially-significant, event it is unlikely that electrical
utility company managers will be interested in Space Weather Forecasting
and the latest GIC prediction systems. For the few thousand dollars
this would cost per month for an electrical utility, to many electrical
power managers, this just doesn't seem to be worth the cost. Many of
them worry about the more obvious sources of traditional power outages
such as ice storms, tornadoes and downed tree-limbs. The lack of a compelling
event hasn't been because the Sun has, somehow, kept a low profile.
Between June and September 1999 alone, 100 CMEs per
month blasted out from the Sun into the dark interplanetary depths,
fully three times the rate that the current solar cycle had started
with back in 1996. The minor blips that the lucky few squalls delivered
to our shores did little more than cause a steady drumbeat of geomagnetic
storminess, and a few good aurora: Great for amateur photographers;
Bad for low-visibility space weather forecasting. We still have another
3-4 years to go before solar minimum conditions are reinstated. If the
first half of this cycle has been an expensive one for satellite insurers,
the second half may still harbor some surprises for us too.
As Cycle 23 pushes beyond its peak and begins its
descent during the next few years, we still have to consider it a cycle
to watch carefully. It will, after all, be during the declining years
of the cycle that much of the planned space real estate will be in place
and serving our needs. Some of the most medically and technologically-troubling
storms have a penchant for happening during the years immediately following
sunspot maximum. Astronauts will be assembling the International Space
Station and inhabiting it in, what many hope, will be 'routine' shifts.
Everyone is counting heavily that space station crews will not have
to be rushed back to Earth to avoid being radiation poisoned. Shuttle
Missions continue to play a cat-and-mouse game with the LEO environment,
but the two days of accumulated spacewalks between 1996-2000 have not
provided much of a target for the Sun's storms. Since Cycle 23 began,
and by the end of December 1999, satellite and ground-based instruments
have steadily ticked off about 80 significant geomagnetic storms, 15
solar proton flares and an unbelievable 2000+ CMEs. Ultimately, we have
to remind ourselves that the game we are playing is not one of Chess,
where pieces always move logically and in recognizable patterns. Instead,
the game is largely one of chance. There are, however, many ways that
we can improve the odds that our technology will survive unscathed.
One of these is simply to become much more adept in anticipating when
solar storm conditions will occur, and what their specific impacts will
be here at the Earth when they arrive.
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