Firefly Blue Ghost Mission 1: SCALPSS 1.1 Post-Landing Terrain Measurements

Images of the lunar surface were taken by the Stereo Cameras for Lunar Plume-Surface Studies (SCALPSS) payload on board the Firefly Aerospace Blue Ghost lander, which successfully completed its first mission in March 2025. Stereo photogrammetry was applied to these images to measure the 3-dimensional post-landing terrain. The terrain measurement was obtained from synthesized high dynamic range (HDR) images from multiple captures taken throughout the first 37 hours of the 14-day lunar surface mission. Four of the six possible stereo pair combinations from the four short focal length (SFL) camera views were used to identify image points spread across the stereo overlap regions. These regions covered much of the terrain beneath the lander but were highly concentrated around one of the four pairs of reaction control system (RCS) thrusters. A custom post-processing workflow was applied to extract features from the images using both manual and semi-automated feature detection and correlation methods. The points were then combined and triangulated to produce a depth map, or digital elevation map (DEM), containing thousands of spatial [𝑿, 𝒀, 𝒁] coordinates, computed in the lander’s reference frame and describing the post-landing lunar terrain. The results presented comprise the first dedicated in-situ measurements for plume-surface interaction at the lunar surface. A discussion of the SCALPSS surface imagery, data processing methods, post-landing terrain measurement results, and a summary of ongoing efforts towards a comprehensive plume-induced erosion measurement are presented.