  The Constellation Project's planned return to the moon requires numerous
landings at the same site. Since the top few centimeters are loosely packed
regolith, plume impingement from the Lander ejects the granular material at
high velocities. Much work is needed to understand the physics of plume
impingement during landing in order to protect hardware surrounding the landing
sites. While mostly qualitative in nature, the Apollo Lunar Module landing
videos can provide a wealth of quantitative information using modern
photogrammetry techniques. The authors have used the digitized videos to
quantify plume impingement effects of the landing exhaust on the lunar surface.
The dust ejection angle from the plume is estimated at 1-3 degrees. The lofted
particle density is estimated at 10^8 - 10^13 particles/m^3. Additionally,
evidence for ejection of large 10-15 cm sized objects and a dependence of
ejection angle on thrust are presented. Further work is ongoing to continue
quantitative analysis of the landing videos.
