00:00but it also brings back old challenges. The heat shield in particular is one of the most critical
00:05aspects of the entire mission. Because Orion doesn't return at around 28 000 kilometers per
00:11hour like a spacecraft from the ISS, but comes back from lunar orbit at about 40 000 kilometers
00:17per hour. That's a massive difference. The thermal stress during re-entry is therefore significantly
00:23higher than during any normal return from earth orbit. We're talking here about temperatures of
00:28almost 2800 degrees, 2800 degrees celsius and extreme mechanical forces. And right at this point
00:36there was a serious warning sign during Artemis 1. During the uncrewed test mission in 2022 the heat
00:44shield showed unexpected damage after returning. During the so-called skip re-entry, where Orion skips
00:51briefly over the atmosphere like a flat stone, heat pockets form beneath some of the protective tiles.
00:57These caused pieces of material to be blasted off in several places. Significantly more wear and tear
01:04than the engineers had expected. NASA then spent two years analyzing this issue, evaluating data and
01:11conducting tests.
