“@SidewalkSciGuy @SpacexFan9876 @Erdayastronaut @Sloppy93 @annerajb @flcnhvy @austinbarnard45 Falcon rocket booster is aluminum-lithium & carbon fiber, which have low max temperature allowables. Super Heavy booster is stainless steel. Since it only goes to around Mach 8 or 9, moreover at high altitude, it needs no heat shield, not even paint.”