I had found it odd, knowing that SpaceX ignites engines at T-2 (and releases clamps at T-0), watching the Arianespace launch earlier in the week. They ignited t

I had found it odd, knowing that SpaceX ignites engines at T-2 (and releases clamps at T-0), watching the Arianespace launch earlier in the week. They ignited the main engine at roughly T-1, then revved it up until T+7, and then fired the solid boosters and released at T+8 or so. https://youtu.be/pgj0kSXEtdQ?t=890 https://youtu.be/pgj0kSXEtdQ?t=890 The STS fired the solids at T-0, thus being the "point of no return", why is it that Arianespace waits until +8 to fire solids? Do they just consider igniting the liquid main stage as "no return" ? Also, SpaceX had a T-1 abort after main engine ignition later too. (the one you showed doesnt even have landing legs!). The later one was SES-9 in Feb 2016 - https://www.youtube.com/watch?v=LuS5mehCAMI https://www.youtube.com/watch?v=LuS5mehCAMI A boat was down-range and the cryo propellants had warmed up and started getting bubbles in it... the engines fire at T-2, run diagnostics, determine if they are running properly, THEN release clamps for lift off, but in this case, the bubbles caused lower than expected thrust, so it turned itself off.