For example the Chinese rocket Jielong 1 has an inverted 4th (final) stage. So the payload sits between 3rd and 4th stage. When 3rd stage separates it has to do a 180 degree turn before igniting the 4th stage.

From: https://www.nasaspaceflight.com/2019/08/china-first-launch-smart-dragon-1-small-satellite-vehicle/

Unusually for satellite launch vehicles, the payload volume is located between the third and fourth stages, with the fourth stage motor and all payloads installed in invert position during launch.

  • $\begingroup$ Just a guess: It might have to do with space constraints. Payloads typically need larger diameters than rocket stages. $\endgroup$ Dec 26, 2021 at 23:15


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.