lination angle result in increased exposure to GCR heavy ions. 3.1.3 Solar Particles Although often referred to as solar flares, the events producing increased energetic particle population in the near earth environment are coronal mass ejections which have no fundamental association with flares. As indicated above, the solar cycle may be divided into solar minimum and solar maximum periods; the majority of solar particle events typically occur near (but not necessarily coincident with) the peak of solar maximum. Although the frequency of occurrence of significant solar particle events is reduced during solar minimum, they can and do occur during this interval as well. Anticipation of the peak in the solar maximum phase in calendar year 2000 has fueled much speculation and press coverage concerning the impact which these events will present to satellite systems. Characteristics of solar particle events observed during the 22nd solar cycle (1986-1997) indicate wide diversity in energy spectra and particle composition. What was once viewed as two event classes, an ordinary event and an anomalously large event, is now viewed as a continuum of possible characteristics, making the definition of a typical event difficult. Systems operating during solar particle events must consider that both solar protons and solar heavy ions produce increased single event effect rates. Solar heavy ions result in minimal contribution to total ionizing dose effects, but peak particle flux levels are often orders of magnitude greater than background GCR. Solar protons contribute to increased levels of single event effects and to both total ionizing dose and displacement damage dose effects in sensitive devices and technologies. It is important to note that the peak elevated flux levels will typically persist for several hours to a few days. As indicated above for GCR heavy ions, the degree of geomagnetic attenuation of the solar particles determines the flux levels which will be present at various orbit altitude and inclination condition