The controversial and delayed test of the Air Force's new antisatellite weapon will take place next Friday with a six-year-old, almost defunct Air Force "Solwind" satellite as target, according to sources in and outside the government.

The aging satellite will present a smaller target for the weapon's infrared homing device. If the test had not been delayed because of problems with the weapon and target, the original target would have been an instrumented balloon, sources said.

Congressional opponents of the system have said they view this first test against a target in space as crucial.

The Air Force postponed the test on Wednesday to avoid violating a congressional notification requirement. Sources said the Pentagon had determined that the requisite 15-day waiting period between presidential notification to Capitol Hill and the test had not expired.

Also on Wednesday, the Soviet news service Tass reported that Kremlin officials said they would feel free to develop and deploy a Soviet space-based antisatellite system if the U.S. test went forward.

The Soviets have refrained from testing their existing rudimentary antisatellite system since 1983.

Air Force officials associated with the U.S. program have told congressional sources that they wanted to wait for the instrumented target to become available but that the decision to proceed this month was made by the White House after a recommendation by Defense Secretary Caspar W. Weinberger.

Weinberger's decision was intended to "show resolve" for the program, according to an Air Force official.

Other administration officials said that, if the test is successful, President Reagan can tout the U.S. antisatellite system at his November summit meeting with Soviet leader Mikhail Gorbachev in Geneva.

That would enable the leaders to discuss on equal terms banning such systems, one official said.