Orbital Insertion Pod glitch
From Halopedia, the Halo wiki
In the level Uprising, kill all the Brutes at the beginning of the level. When the Elites meet up with you, look carefully where the friendly pods land and memorize the locations. Then, revert to the last checkpoint, push your ally off the ledge, and stand directly where a pod will drop.
If executed correctly, you will end up inside the pod. However, when the door flies open, you will be launched out. To stay inside, kill the Sangheili inside the pod. The door will not open, but you will be trapped inside.