Lunar permanently shadowed regions (PSRs) never see direct sunlight and are illuminated only by secondary illumination - light reflected from nearby topography. The ShadowCam imaging experiment onboard the Korea Pathfinder Lunar Orbiter is acquiring images of these PSRs. We characterize and discuss the nature of secondary illumination for the Shackleton PSR from ShadowCam radiance-calibrated images. We also use modeling to understand the magnitude and direction of the secondary illumination. Results from our analysis highlight the non-homogeneous, dynamic, and complex nature of PSR secondary lighting. Knowledge of the direction of the secondary illumination is crucial for reli-able interpretation of contrasts observed in ShadowCam images. This preliminary analysis of the floor of Shackleton crater from images acquired over multiple secondary illumination conditions does not reveal indications of exposed surface ice, even though temperatures are constantly below 110K.

Lunar polar volatiles, such as water ice, are essential lunar exploration objects. The conceptual design for China's Chang'E-7 lunar exploration mission to the South Pole was proposed. The mission comprises an orbiter, a lander, a rover, a leaper, and a relay satellite. The orbiter can provide high-resolution images to select a suitable landing site. The rover and leaper will be deployed for in-situ exploration in sunlit areas and permanently shadowed regions, respectively. The relay satellite will transmit all data to the ground. We calculated the accumulated illumination, as an engineering condition, within a 15 kmx15 km area partially covering the Shackleton crater from January 1, 2024, to December 31, 2026. Two potential landing sites-areas SR1 and CR1-were analyzed in detail by comparing their average illumination rate, slope, and distance to the exploration target. Additionally, we simulated the electric field of the Shackleton crater within a 37 kmx27 km area, considering the effect of the plasma wake on the electric field in shadowed areas. The results show that the maximum surface potential near the rims is less than 2.1 V, while the minimum surface potential at the bottom of the crater can reach as low as -500 V due to the plasma wake effect. Therefore, a risk assessment is necessary, especially for the exploration of the leaper at the bottom of the Shackleton crater.