Note that while the temperature rockets up to 1000C in the upper atmosphere (thermosphere), it's offset by the decrease in density: almost a thousand-fold betwe

Note that while the temperature rockets up to 1000C in the upper atmosphere (thermosphere), it's offset by the decrease in density: almost a thousand-fold between 100-150 km. High temperature is not the same as hot. Those particles have a high temperature which means they're moving around a lot (crude estimate from conservation of energy: v = √kT/m). When you touch a "hot" thing, the heat you feel is all those particles bumping into your body. So in the upper atmosphere those particles might be very excited, but the low density means there isn't sufficient heat transfer to burn you. EDIT: There are other interesting considerations. Rocket controllers use precise atmospheric models to know when to throttle down/up during a launch. There is a point called maximum dynamic pressure (max Q) where the stress on the airframe is maximised due to the speed of the vehicle and local air pressure. On Shuttle launches you hear the controllers call out "Go at throttle up" to let the pilot know that it's safe to punch the engines. https://www.youtube.com/watch?v=Em-Krwbn25A https://www.youtube.com/watch?v=Em-Krwbn25A