You and anyone else technically minded might appreciate this:
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From:
http://lasp.colorado.edu/stp/publications/galaxy.html Space Environmental Conditions During April and May 1998: An Indicator for the Upcoming Solar Maximum
D.N. Baker, J.H. Allen, S. G. Kanekal, and G.D. Reeves
Introduction
At approximately 2200 UT on 19 May 1998, the PanAmSat Corporation's Galaxy 4 spacecraft experienced a failure in its attitude control system (Automatic Pointing Control, APC). Unfortunately, the backup system also had failed, either at that same time or earlier, so that the operators were unable to maintain stable Earth-link [Space News, 25-31 May 1998, p. 3]. The Galaxy 4 spacecraft is a heavily used communication satellite at geostationary orbit; its sudden failure caused the loss of pager service to some 45 million customers as well as numerous other communication outages [USA Today, p. 1, 21 May 1998].
Analysis by PanAmSat and Hughes continues as to the exact cause of the Galaxy 4 failure [Space News, ibid., p. 18]. Whenever there is an operational problem with space hardware, it is advisable to examine as broadly as possible the space environmental conditions prior to and at the time of the problem. Using a wide array of space data sets, we have analyzed the magnetospheric and solar wind conditions during the April-May 1998 period. There was large solar and magnetic activity in early May, but geomagnetic conditions were very quiet by 19 May. Moreover, the Galaxy 4 failure occurred when the satellite was in the afternoon local time sector. Thus, surface charging of the spacecraft was not a likely factor. However, strong evidence is found that highly relativistic electron [HRE] fluxes were substantially elevated above average conditions for a period of about two weeks prior to the 19 May failure of Galaxy 4.
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Summary and Discussion
We have considered the space environmental conditions in April and May of 1998. We find evidence of highly disturbed solar, solar wind, and geomagnetic conditions in late April and early May. The combination of coronal mass ejections, solar flares, and high speed solar wind streams led to a powerful sequence of solar wind drivers of magnetospheric processes at the Earth. The result of the compounding solar wind disturbances was to produce a deep, powerful, and long- lasting enhancement of the highly relativistic electron population throughout the outer terrestrial radiation zone. Previous such enhancements of the HRE population have been shown to have caused spacecraft anomalies due to deep dielectric charging.
Based on the above results, it is possible that the Galaxy 4 spacecraft problem was caused, or at least exacerbated, by the energetic electron environment at geostationary orbit during May 1998. Given the long, intense duration of electron flux enhancement seen from early to late May of 1998, the circumstances were quite conducive to produce deep dielectric, (or bulk) charging [see Vampola, 1987].
In attempting to associate a given spacecraft anomaly with the space environment, it is often asked why did only this particular spacecraft have a problem? Why did not other spacecraft also fail at the same time? Moreover, since the typical geostationary orbit spacecraft has experienced numerous other HRE enhancements, why did it not fail earlier during another event?
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PanAmSat's investigation revealed however:
From:
http://www.panamsat.com/_media/company/pdf/PAS_FINANCIAL_FINAL.pdf The 1998 Annual Report
SPACECRAFT DEVELOPMENTS
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During 1998, three of the Company's satellites
experienced what is believed to be a related anomaly
in their on-board SCPs. On May 19, 1998, all customer
services on Galaxy IV were permanently lost
when the satellite experienced an SCP failure that
caused the satellite to rotate and lose its fixed orientation
with the Earth. The spare SCP was unavailable
due to an earlier unrelated event that had not been
previously detected. The Company submitted an
insurance claim for this loss and received $162.5
million in 1998. For non-pre-emptible customers,
service was restored with the use of capacity on
other Company satellites, including capacity previously
used by certain customers whose service
was subject to preemption and terminated in
accordance with their agreements. Subsequently,
two others satellites (Galaxy VII and PAS-4) had
primary SCP failures but are operating normally on
back-up systems.
An investigation of the anomaly, conducted by
Hughes Space and Communications Company, an
affiliate of the Company and the manufacturer of
the three affected satellites, identified electrical
short circuits involving tin-plated relay switches as
the most probable cause of the SCP failures. The
report concluded that the short circuits can occur
only when several factors are concurrently present.
Of the 14 satellites owned by PanAmSat that were
constructed by HSC, five satellites (including PAS-4
and Galaxy VII) are the same model spacecraft as
the affected satellites, and have tin-plated relay
switches similar to the switches on the failed
SCPs. No assurance can be given that additional
SCP failures will not occur.
Bump.
Another CME was already en route when this morning's explosion occured. Pictured right, it was launched on Oct 22nd by an explosion near sunspot 484. Forecasters expect it to arrive on Oct. 24th and possibly trigger a strong geomagnetic storm. Sky watchers at middle latitudes should be alert for auroras.
