A method of troop deployment.
The Single-Occupant Exoatmospheric Insertion Vehicle, or SOEIV, commonly referred to as a drop pod, is a variant of the Human Entry Vehicle, a method of troop deployment from very high altitudes or in many cases from space. Drop pods are most commonly used by Orbital Drop Shock Troopers (ODSTs), although conventional Marines and even Spartans have been known to use them in certain circumstances.
The unwieldy rectangular shape is roughly over five meters long from nose to tail, with a bulk span of three meters and a width of similar dimensions. Within a standard SOEIV, an occupant would have access to a crash seat with secured belts, controls for maneuvering the pod, and a variety of communication systems which would allow synchronization with others being deployed during a given drop. Weapon and equipment racks are filled prior to drops and once a successful drop has been achieved, the single hatch is expelled by way of an explosive-gas bolt system triggered by the occupant.
Combat drops such as this were historically performed during the wars of the early 20th century by paratroopers who used them to circumvent enemy lines. In the 26th century, the reasons for such deployment has changed very little—although the near ubiquity of meteor and other debris showers in many solar systems adds another strategic component to this type of insertion.
ODSTs are typically deployed from high altitude or from an exoatmospheric location, being fired toward the planet's surface until the atmosphere is breached. At this point, the occupant is free-falling at terminal velocity until the pod's automated braking-chute system is initiated, thrusting the pod backward prior to its terrestrial contact—the intended result being a safe landing.
Many drops, however, do not end safely. Though these engagements have low overall attrition yields due to the singular occupant nature of the drops, the heightened risk of equipment malfunction or user error make it extremely dangerous.
Still, this type of combat infiltration is not uncommon even across different species. During the war with the Covenant, the UNSC observed that Elites were being deployed into combat through similar means, alongside equipment pods and other materiel. Some reports even indicate that the extragalactic parasite known as the Flood used an analogous method of deployment across large spans of localized space, a testament to the overall science and philosophy of such techniques.