Why do space vehicles heat up when they enter the atmosphere?

Question

Layla Anderson · Accepted Answer

Due to drag by fluid (air) friction that is directly proportional to air density, face area and square of velocity of the space vehicle

Similar to fast-moving meteors entering the atmosphere, spacecraft experience heating from air friction. This heat is produced by the vehicle's resistance to fluid friction, which can cause the vehicle to burn and disintegrate. A safe landing is achievable by streamlining the vehicle, covering it with materials resistant to heat, and stroking it to slow down. The formula for drag force for higher entry- velocities is #f_(drag)=-(1/2)C rho A v^2#, where #rho# is air density, A is face area, C is drag coefficient and v is the velocity of the vehicle. Visit www.hyperphysics.phy-astr.gsu.edu/hbase/airfri.html for related formulas.

Luke Allen · Answer

undefined Air compression and friction cause spacecraft to heat up when they enter the atmosphere. As the vehicle descends, it presses against the molecules of air, which causes them to compress and heat up. The high speeds also cause friction between the air molecules and the spacecraft, which produces more heat.