Editing Retrorocket (section)

===Launch vehicle staging===

To ensure clean separation and prevent contact, [[multistage rocket]]s such as the [[LGM-25C Titan II|Titan II]], [[Saturn I]], [[Saturn IB]], and [[Saturn V]] may have small retrorockets on lower stages, which ignite upon stage separation. For example, they were used to back the [[S-IC]] and [[S-II]] stages off from the rest of the vehicle after their respective shutdowns during the Saturn V's launch to Earth orbit. Meanwhile, the succeeding stage may have posigrade [[ullage rocket]]s, both to aid separation and ensure good starting of liquid-fuel engines.