A penetrator assembly for penetrating a bone and associated bone marrow is provided. The penetrator assembly may include a first connector having a first end and a second end； an outer penetrator extending from the second end of the first connector； the outer penetrator comprising a longitudinal passageway and a first tip； a second connector having a first end and a second end； and an inner penetrator extending from the second end of the second connector, the inner penetrator comprising a second tip. The first connector may be configured to engage the second connector, and the inner penetrator may be disposed in the longitudinal passageway of the outer penetrator when the first connector is engaged with the second connector.
