Patent ID: 8091481

Claim:
A staged rocket apparatus comprising: a first stage; a second stage; and a gas strut connected between the first and second stages, the gas strut including: an outer strut housing including a bore defined therein; a metering rod attached to the housing and extending axially into the bore; an inner strut rod including a piston end slidably received in the bore, the piston end including an exterior end surface communicated with the bore, and the piston end including an axial opening through which the metering rod is slidably received; a high pressure chamber defined within the inner strut rod; a low pressure chamber defined as part of the housing bore surrounding the metering rod and communicated with the exterior end surface of the piston end of the strut rod; and a variable area metering passage defined by the metering rod and the axial opening of the piston end, the passage being closed when the strut rod is in a first telescopingly collapsed position relative to the strut housing, and the passage having an increasing passage flow area as the strut rod telescopes outwardly relative to the strut housing.