,
5 tweets,
1 min read
Read on Twitter
Wow, excited to learn today that a third proposal was selected for funding. And guess what: it is focused on predictive computer modeling of rocket exhaust eroding soil during lunar landings. This is actually a different focus than the other two, but yes they do sound similar 😅
Here’s the difference: one focuses on surface scour eroding and blowing soil. Another is deep cratering, where the plume pushes the soil down to make a deep crater. (Didn’t happen in Apollo.) The third is how the ejected stuff gets reflected back at the vehicle and causes damage.
That DOES happen — reflection of ejecta back toward the vehicle. The Surveyor 3 camera was returned to Earth by Apollo 12; we could see its camera lens was etched by its own landing as ejecta bounced off nearby rocks at high speed back toward the lander. In vacuum that happens.
We could tell this etching of its lens happened during its own landing, because its camera was NOT pointed toward the Apollo lander. We could see 2 etched curves caused by the shadowing of its sun shade as 2 different rocks were reflecting ejecta back at it.
Moral of the story: in vacuum, dust bounces. It doesn’t happen in Earth’s atmosphere so our minds want to neglect that effect. But on the Moon, dust really does bounce.
