Adapter (rocketry)Interstage of the UGM-73 Poseidon missile. First stage is on the right, separated second stage - on the left
In rocketry, an adapter is a hollow cylindrical[1] or conical segment[2] which provides a sound aerodynamic and structural connection, either between rocket stages (often referred to as an interstage) or between a spacecraft and the top rocket stage (referred to as a payload adapter). It may shroud and protect vulnerable systems such as electrics or machinery of rocket engines/spacecraft from weather or vibrations caused by running engines.[3] It is discarded during staging.
Examples of rocket stages featuring an interstage adapter:
Examples of rocket stages featuring a payload adapter:
(Planned) The Exploration Upper Stage (EUS) of SLS Block 1B/2 is expected to connect large secondary co-manifested payloads using the Universal Stage Adapter (USA).[11]