Like most spacecraft returning from orbit, the Apollo command module entered the atmosphere at 7.8 km/s. In front of the capsule was a shock front, the leading edge of the shock front we call a bow shock. Let’s consider the conditions as it passes an altitude of 40,000 feet, at 461 miles per hour. 1a) What are the density, pressure, and temperature behind the shock front? 1b) In the frame of the shock, what is the velocity at which the gas approaches the shock? What is the velocity with which the gas leaves the shock? 1c) In the frame fixed on the Earth, what is the velocity of the post- shock gas?

Like most spacecraft returning from orbit, the Apollo command module entered the atmosphere at 7.8 km/s. In front of the capsule was a shock front, the leading edge of the shock front we call a bow shock. Let’s consider the conditions as it passes an altitude of 40,000 feet, at 461 miles per hour. 1a) What are the density, pressure, and temperature behind the shock front? 1b) In the frame of the shock, what is the velocity at which the gas approaches the shock? What is the velocity with which the gas leaves the shock? 1c) In the frame fixed on the Earth, what is the velocity of the post- shock gas?