has been discontinued. The Nozzle assembly uses a 3D carbon-carbon throat and a carbon-phenolic exit cone. Maximum propellant weight is 2350 pounds, while the motor has been qualified for propellant off-loading to 2257 pounds. A spin-stabilized or thrust-vectoring version of Star 37 is used as the final stage of the Minotaur V launch vehicle. The Pioneer 10 & 11, and Voyager 1 & 2 Propulsion Modules used Star 37E motors; each is now on a similar interstellar trajectory to its companion probe, and is set to leave the Solar System (except the Pioneer 11 stage, which is thought to have remained in solar orbit). Star 48 The Star 48 is a type of solid rocket motor developed primarily by Thiokol Propulsion, which was purchased by Orbital ATK in 2001. In 2018, Orbital ATK in turn was acquired by Northrop Grumman. The "48" designation refers to the approximate diameter of the fuel casing in inches; Thiokol had also manufactured other motors such as the Star 37 and Star 30. Internally, Thiokol's designation was TE-M-711 for early versions, and TE-M-799 for later ones. Subtypes are given one or more letter suffixes after the diameter number, or a trailing number (i.e., "-2") after the internal designation. The "T" prefix stands for Thiokol, and the following letter refers to the company division that developed the rocket motor. In this case, "E" refers to the Elkton, MD division and the "M" stands for motor. The most common use of the Star 48 was as the final stage of the Delta II launch vehicles. Other launchers such as ULA's Atlas 551 have also incorporated the motor, but with lower frequency. Onboard the Space Shuttle, the complete stage (motor plus accessories) was referred to as the Payload Assist Module (PAM), as the Shuttle could only take satellites to low Earth orbit. Because geostationary orbit is much more lucrative, the additional stage was needed for the final leg of the journey. On such missions, the stage was spin-stabilized. A turntable, mounted in the shuttle payload bay or atop the previous Delta stage, spun the PAM and payload to approximately 60 rpm prior to release. Usually after motor burnout and just prior to satellite release the spin is canceled out using a yo-yo de-spin technique. A non-spinning, thrust-vectoring version of the Star 48 is available ("Star 48BV"), but much less common. A thrust-vectoring Star 48 is the final stage