Phase
Low Earth orbit
Falling around the planet at 7.66 km/s. Coming home does not need much fuel — only a short burn against the direction of travel to lower the far side of the orbit into the atmosphere.
408km
Altitude
Velocity
7.66km/s
Heat shield
20°C
Air pressure
0.0e+0atm
Outside air
210°C
—
In orbit, awaiting deorbit burn
408 km to zero
Getting up there costs a rocket. Coming back costs a shield.
Almost none of the descent is powered. A short burn against the direction of travel drops the far side of the orbit into the atmosphere, and from there the air does all the work — turning 7.66 km/s into heat, and the heat into a glow you could see from the ground.