LightSail 2’s Average Daily Change in Altitude with Time and Solar Activity

LightSail 2’s Average Daily Change in Altitude with Time and Solar Activity
LightSail 2’s Average Daily Change in Altitude with Time and Solar Activity LightSail 2’s average daily change in altitude with time is shown in green. The radio flux received on Earth at 10.7 cm wavelength (F10.7) is shown in orange. The F10.7 parameter is a good proxy for solar activity. Note the much larger drops in daily altitude as solar activity increased which caused increased atmospheric drag due to the heating and resulting expansion of the atmosphere. During the recent months of high solar activity, the daily change in altitude is inversely correlated with F10.7, indicating the expansion and contraction of the atmosphere is dominating the rate of orbital decay. In contrast, note the period of daily altitude increases around August 2021 that are not strongly correlated with solar activity indicating solar sailing is the dominant effect and was particularly efficient during that time period. This plot shows data as of June 22, 2022. The Planetary Society