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| Progress Overview |
| Secondary Objective |
| During STS-106, the astronauts will transfer logistical material from the Progress supply vehicle to the ISS. The Progress is an automated version of the Soyuz, and was developed to carry propellant and cargo to the Salyut and Mir space station. It will serve the same purpose for the ISS. Although ISS has its own propulsion system, generally it is the Progress vehicle that will perform periodic reboost maneuvers to maintain the ISS orbital altitude. The Progress is approximately the same size as the Soyuz, but it has a slightly higher mass at launch of approximately 7150 kg. The Progress spacecraft docks automatically to the ISS, and the TORU system acts as a backup remote control docking system. The Progress is composed of three modules: the Cargo Module, the Refueling Module, and the Instrument/Propulsion Module. A modified version of the Progress M, called the Progress M1, is planned for operation with the ISS. This version will have more propellant tanks for refueling, as the entire Refueling Module is devoted to fuel. Water will be carried in the Cargo Module. The Progress payload includes cargo in the pressurized Cargo Module and propellant in the Refueling Module. Excess propellant that is usually in the propulsion system tanks in the Instrumentation/ Propulsion Module can also be used by the ISS. The table below summarizes the approximate payload capacity of the Progress vehicle
The relative amounts of pressurized cargo, refueling propellant, air, and water will vary within the constraints of the total payload limit. For example, if the maximum amount of propellant is carried, the amount of pressurized cargo will be less than the maximum amount. The payload masses for Progress M1 will increase within the ranges shown as improvements are made to the Soyuz launch vehicle. The lowest value corresponds to the capability with the current Soyuz launcher. Cargo Module The Progress Cargo Module is similar in construction to the Soyuz Orbital Module. The Cargo Module carries pressurized cargo that the crew transfers into the ISS through the docking hatch. After the Cargo Module is unloaded, trash, unwanted equipment, and wastewater can be loaded into the Progress for disposal when the spacecraft leaves the ISS. Refueling Module In place of the Soyuz Descent Module, the Progress has a module containing propellant tanks. The Progress is able to transfer propellant into the ISS propulsion system through fluid connectors in the docking ring. The propellant in the Refueling Module can also be used by the thrusters on the Progress vehicle for controlling and reboosting the ISS. The Progress M has four propellant tanks (two each for fuel and oxidizer) and two water tanks. The Progress M1 will have eight propellant tanks and no water tanks. In the Progress M1, water will be delivered in separate containers carried in the Cargo Module. Instrumentation/Propulsion Module The Progress Instrumentation/Propulsion Module is similar to the module on Soyuz, but on Progress it is twice as long and contains additional avionics equipment. The larger Instrumentation Compartment carries avionics that would be contained in the Descent Module in the Soyuz. |
