Abstract: An arrangement for attaching and quickly disconnecting and jettisoning a rocket booster from a core space vehicle. The arrangement includes a housing connected at one end to the booster and a segmented nut carried within the housing that threadedly engages a bolt end of an interface mounting clevis secured to the space vehicle. A retainer both locks the segmented nut on the bolt and is responsive to high pressure fluid to slide out of locking engagement with the nut and to urge a conically shaped wedge into a shaped end of the segmented nut to force the segments outwardly out of threaded engagement with the bolt end to disconnect the booster from the space vehicle. High pressure fluid is also applied to a piston having a plunger in engagement with the bolt end so that the bolt end is swiftly driven out of the housing and the booster is thereby jettisoned form the space vehicle. The high pressure fluid is preferably provided by a pyrotechnic device.