# Impact of Mega Constellations on Geospace Safety
## 4 Impact of Starlink on Control Avoidance Strategies for low-orbiting Satellites in Geospace
### Impact on LEO Space Target Satellite Deorbit Capability  
In order to refine the impact of Starlink on the target satellite in terms of risk and avoidance operations, this section presents the changes in \(\Delta V\) and propellant mass fraction (PMF) required before and after considering Starlink for different ACPL values. The effects of early and temporary Orbital maneuvering on these values are also indicated. The \(\Delta V\) required for the three target satellites to avoid control is depicted in Figure 9, which shows the earliest \(\Delta V\) from 10 revolutions ago to avoid control in advance. In order to summarize the data in more comprehensive detail, the data in Figure 9 are summarized in Table 4, and the more concerned information is extracted from the figure for visual comparison. There, 0 Revs/10 Revs indicates the ratio of \(\Delta V\) consumed at 0 Revolutions to that consumed at 10 Revolutions. Also, With Starlink ACPL/Without Starlink ACPL indicate the ratio of \(\Delta V\) consumed with and without Starlink. In Figure 9a,b a smaller ACPL value requires a larger \(\Delta V\) value to be satisfied, and the \(\Delta V\) of ACPL-\(10^{-6}\) and ACPL-\(10^{-4}\) without advance avoidance control is 9.08- and 4.837-times that of avoidance control with 10 revolutions in advance. ACPL-\(10^{-6}\) and ACPL-\(10^{-4}\) without early avoidance control are 7.16- and 5.837-times those with 10 revolutions of early avoidance control. Without early avoidance control, ACPL-\(10^{-6}\)-\(\Delta V\) and ACPL-\(10^{-4}\)-\(\Delta V\) are 3.98- and 2.27-times of those with Starlink, respectively, and ACPL-\(10^{-6}\)-\(\Delta V\) and ACPL-\(10^{-4}\)-\(\Delta V\) with 10 revolutions of early avoidance control are 3.98- and 2.27-times of those with Starlink. ACPL-\(10^{-6}\)-\(\Delta V\) and ACPL-\(10^{-4}\)-\(\Delta V\) are 5.05- and 1.88-times the considered ones, respectively. In Figure 9c,d the difference with Figure 9a,b is the change in order of magnitude. After considering Starlink, the \(\Delta V\) surge, without advance avoidance control, ACPL-\(10^{-6}\)-\(\Delta V\) becomes 82.822 times before considering Starlink, ACPL-\(10^{-4}\)-\(\Delta V\) becomes 556.129 times, and with advance avoidance control, ACPL-\(10^{-6}\)-\(\Delta V\) becomes 56.944 times before considering Starlink, ACPL-\(10^{-4}\)-\(\Delta V\) becomes 332.733 times. At 10 revolutions of avoidance control, ACPL-\(10^{-6}\)-\(\Delta V\) becomes 56.944 times and ACPL-\(10^{-4}\)-\(\Delta V\) becomes 332.733 times before Starlink is considered, and the effect of Starlink on CORVUS BC5 is more severe, which is consistent with the flux changes reflected in Section 3. In the case of avoidance control by considering Starlink, a greater change in \(\Delta V\) is required for early avoidance control than for immediate avoidance control, for example, the \(\Delta V\) ratio is 26.050 for both without Starlink, 43.535 with Starlink considered, and 9.055 and 13.170 with ACPL-\(10^{-4}\), respectively. Figure 9: Required for different ACPL values in ten revolutions to change track \(\Delta V\)_(**a,b**) Comparison of different \(\Delta V\) variations with and without Starlink for GAOFEN; (**c,d**) Comparison of different \(\Delta V\) variations with and without Starlink for CORVUS BC5; (**e,f**) Comparison of different \(\Delta V\) variations with and without Starlink for YAOGAN-. Figure 9e,f shows a pattern similar to that of Figure 9c,d. Figure 9 reflects a general pattern in which \(\Delta V\) without advance control avoidance is much larger than that without Starlink, which only occurs in CORVUS BC5 and YAOGAN-35C, and YAOGAN -35C is much better than CORVUS BC5. According to the characteristics of the three target satellites, when only the three factors of altitude, inclination, and area are considered, the orbit altitude has a greater impact on the avoidance operation, the target satellite's area has a greater impact, and inclination has a minor impact.