The invention presented here relates to a device in a spacecraft comprising a carrier rocket, a satellite and a detachable adapter (4) for connecting a satellite to the carrier rocket, where the adapter (4) comprises a wall structure (14, 15) for supporting the satellite on the carrier rocket, and is fixed at its lower rim to the carrier rocket and is fixed at its upper rim to the satellite. The device is characterised in that the adapter (4) is divided essentially across the longitudinal direction of the spacecraft and that both of the adapter parts (12, 13) are detachably connected to each other. The invention comprises the said adapter design and a method for separating the invented device.