Benefits of a reusable propulsion system - TMS

The Teleoperator Maneuvering System (TMS) is a disk-shaped lightweight structure approximately 1 m long with a diameter that just fits into the Orbiter's payload bay. When fully loaded, it weighs approximately 4000 kg, with approximately 65 percent of the weight due to the propellant. It carries a television camera and a radar for rendezvous and docking. For attitude knowledge and pointing control, it employs an inertial reference unit with horizon scanners and a sun sensor for inertial-reference updates. The advantages which the TMS offers over the previously proposed Shuttle Orbital Maneuvering System (OMS) delta-V kits are summarized. Attention is also given to the question of whether direct insertion of a payload by the Orbiter is more economical than employing the TMS. It is shown that the TMS can deliver a large number of payloads under various conditions which cannot be satisfied by the Shuttle using direct insertion. A comparison is also made between the TMS and the delivery of payloads into higher orbits from the Orbiter by means of an integral propulsion system.