Once in orbit, it was not possible for the spacecraft to change its trajectory except by initiating reentry. Each orbit would typically take 88 minutes to complete. The lowest point of the orbit, called perigee, was at about altitude, and the highest point, called apogee, was about altitude. When leaving orbit (E), the angle of retrofire was 34° downward from the flight path angle. Retrorockets fired for 10 seconds each (F) in a sequence where one started 5 seconds after the other. During reentry (G), the astronaut would experience about 8 g (11–12 g on a suborbital mission). The temperature around the heat shield rose to and at the same time, there was a two-minute radio blackout due to ionization of the air around the spacecraft.