Solar Cycle Effects on the Near-Earth Plasmas and Space Systems

Solar physicists have predicted that the upcoming maximum of solar activity, scheduled to occur near 1990, might be the most extreme ever recorded. Based on the observed rate of increase in solar activity starting with the most recent minimum in 1986 the upcoming solar maximum will be the most severe of those which have occurred during the space age. Correlations between solar activity and disturbances in the near-earth magnetospheric and ionospheric plasmas which adversely affect communications and space systems are well documented. The implementation of larger, more complex and perhaps more susceptible space systems over the last decade, has led to concern and speculation about the expected performance and survivability of these space systems over the next decade. Unfortunately, because of the complex and sometimes indirect interactions between the sun and the plasma environment in near-earth space, very few firm quantitative predictions can be made regarding the expected effects of an extreme solar maximum on the near-earth environment or on the complex systems operating in that environment. A number of qualitative predictions can be made with high confidence. Satellite communications links in the VHFUHF range will suffer signal fades more often and with greater severity. Short wave and airline communications will be sporadically disrupted. Satellites will experience electrical charging of their surface and internal dielectric components, resulting in disruptive electrostatic discharges and micro- electronic devices on satellites will experience upsets more often.