/sci/ - Science & Math

>>16073031
booster performed well
anon above explained the cause of FTS
more observations here: the upper stage didn't achieve a particularly high speed (just under 7 km/s; you'd want closer to 8 km/s to be on orbit) and it cut off about 20 seconds early.
Back-of-the-envelope extrapolation suggests they were just about those 20 seconds short of reaching the necessary velocity.
Then they lost the upper stage.
Personally I'd set aside the matter of stage landings for now (it's a secondary mission objective relative to achieving orbit), and focus on why the second stage underperformed.
There wasn't anything obvious wrong; there must have either been some extra mass along for the ride, some amount of engines performing at reduced capacity (didn't see any signs of this), or just worse performance than they assumed in the design.
Even if it did achieve orbit, it looks extremely marginal - this backs up the most pessimistic assessments of its actual cargo capacity.
TLDR: I suspect the second stage problems point to a more fundamental challenge that will not be easy to resolve.

SLS isn't as small as I thought
Comparison graphs don't really give good perspective
Soyuz is next to be extruded