When - and if - the United States space station becomes fully operational in 1997, as now planned, Peace and Freedom will circle the Earth. The Soviet station Mir (Peace) is already on orbit with Vladimir Titov, Musa Manarov, and Valery Polyakov on board. Cosmonauts Titov and Manarov entered Mir Last Dec. 21 and hope to stay a year. Dr. Polyakov, a space endurance expert, joined them Aug. 31.
Meanwhile, Freedom - as President Reagan has named the planned US space station - faces an uncertain future. Congress gave NASA the $900 million it wants for the project in fiscal 1989. But only half of that is available Oct. 1. The rest will be spendable May 15 only if the new president wants it.
If the station does proceed, it will be a major international venture with Canada, Europe, and Japan supplying equipment and services that amount to about 20 percent of the $21 billion to $25 billion start-up cost. These partners are due to sign the governing agreement in Washington Sept. 29, the day the shuttle Discovery is to return to orbit.
As now planned, Freedom will be a linear truss 80 meters (262 feet) long with a 37.5-meter (123-foot) long power unit at each end. These units will carry solar cells to deliver 75 kilowatts total power. In the center of the truss, four modules with a total volume of 750 cubic meters (26,500 cubic feet) will provide work and living space for eight astronauts. Pressured nodal areas with control panels and airlocks will link the modules. The US will supply a living module and a laboratory module. Europe and Japan will supply a lab module each. Canada will contribute an external servicing center with a robot arm. Instruments and other equipment can be mounted along the truss.
Some 20 shuttle missions will be needed to build the station between 1994 and 1997. The partners can later extend the station by adding more trusses and modules.
Mir is also modular with a multi-port docking unit. Currently, the main living unit has the Kvant (quantum) astronomical observatory docked at one end and a Soyuz personnel carrier at the other end. Together the complex extends 25.9 meters (85 feet). With solar panels spread, it spans 29.7 meters (97.4 feet). The Soviets can expand Mir by adding modules laterally. A 30,000-pound Earth-observing station may be added this fall.
Mir enables the Soviets to carry out research that now is beyond US capability. That includes gaining valuable experience with long-duration weightlessness. Countries that want to do extended on-orbit research, such as France, are beginning to accept Soviet offers of space on Mir.