The probability that debris will collide with a given spacecraft depends on the spacecraft's size and the debris flux through its orbital region. The effect of spacecraft size on the likelihood of being struck is simple; the chance of impact is directly proportional to the spacecraft's cross-sectional area relative to the debris flux and the amount of time exposed to the environment. The relationship between the probability of collision and the orbital region is far more complex, varying significantly with altitude and to a lesser degree with inclination.
Although Figure 4-1 oversimplifies the nature of the LEO debris population, it provides a starting point for estimating the debris impact probability for spacecraft in LEO by showing how the flux of debris varies with debris size. The main oversimplification is the grouping of data