Propulsion pod
From Halopedia, the Halo wiki
Propulsion Pods are bulbous, about 1/10th the size of a human Freighter looking somewhat like tugboats used to push supertankers out to sea. They connect the rear of the vehicle with a powerful magnetic coupling and are used to give those human space vehicles (mainly Freighters) that did not have a Shaw-Fujikawa Slipspace Drive built into them the ability to enter Slipspace. [1]
- ^ Halo: Contact Harvest p.23
