Senior officials at the Pentagon and the White House, and not Air Force commanders, pushed the decision to hold the first test next month of the problem-plagued antisatellite weapon against a target in space, according to sources.

The decision was made, sources inside and outside the government said, to send a message to the Soviet Union and to Congress about the administration's resolve to proceed with the weapon, even though the test will provide considerably less useful information than the one the Air Force had originally planned to conduct.

That test, which already is over a year behind schedule, was last set for July, but the Air Force delayed it because the weapon and the instrumented target it was supposed to hit in space had developed technical problems. The units were returned to manufacturers for repairs. The Air Force expected to reschedule the test in a few months.

Early this month, however, when the latest problem with the weapon was solved quicker than expected, Defense Secretary Caspar W. Weinberger recommended that President Reagan approve a test without the instrumented target "to show resolve," one Pentagon official said yesterday.

As a result, the antisatellite weapon is now to be launched next month against an aging U.S. satellite which, though still performing some experiments, long ago surpassed its expected operational life, according to Pentagon sources.

However, without the sensing devices on the originally planned instrumented target, it will be a hit or miss test. If the weapon misses, "we won't know by how much we missed," an Air Force official conceded yesterday.

If it is not delayed again, the controversial shot will come over a month before the November summit meeting in Geneva between Reagan and Soviet leader Mikhail Gorbachev and just before the end of the government's fiscal year Sept. 30.

Holding the test in September would save face with Congress, a Capitol Hill aide said yesterday. Last year, Weinberger argued against a congressional limit of two successful tests, or three tests, against a target. Now, because of technical problems, he will be lucky if one test takes place.

Administration officials who favored the early test appeared willing to gamble that the ASAT weapon will hit the satellite, giving Reagan the opportunity "symbolically . . . to say we also have a weapon" in his meeting with Gorbachev, one official said.

He noted the impact made a year ago when an experimental U.S. antimissile device hit an incoming warhead in a test over the Pacific, showing that a missile could hit a missile. However, that 1984 test was the fourth attempted over several years; the three previous ones all failed.

If the antisatellite test next month is successful, one official said, "that could pave the way for talks about banning further development of the two specific antisatellite weapons each country possesses."

Such a "system specific" agreement, the official said, would allow both sides to continue to pursue other space defense devices, including lasers, that would be useful as either antisatellite or antimissile weapons. This would allow the United States to continue research on the Strategic Defense Initiative, a possible shield against Soviet missiles.

The president and his aides have steadily maintained that they cannot find a way to verify a comprehensive ban against testing and deployment of all antisatellite weapons. But top officials, including the president's special adviser on arms control, Paul H. Nitze, have suggested a "system specific" agreement banning only the current Soviet and planned U.S. systems could be worked out.

The existing Soviet antisatellite system, which is launched from a missile and goes into orbit chasing its target, is considered rudimentary by most U.S. experts. The proposed U.S. system, which has never had the full support of the Air Force, is now considered costly and obsolete by many experts in the face of new space technology, although it is much more sophisticated than the Soviet ASAT weapon.

As currently planned, a U.S. F15 fighter would carry aloft a two-stage rocket which would launch an infrared homing device toward the target satellite. The device would then maneuver to collide with the satellite, thus destroying it.

The U.S. antisatellite program, ironically, was begun in 1978 under the Carter administration as a bargaining chip for an antisatellite agreement with the Soviets.

Those negotiations foundered when the Soviets demanded that the U.S. space shuttle be included and then were broken off early in 1980 after Moscow's invasion of Afghanistan.

Under the original Carter program schedule, the device was to have been operational by now, but the system has run into a series of technical problems.

Air Force Secretary Verne Orr, when confronted by questions over delays in the program during his appearance before the House Appropriations subcommittee on defense in April, admitted there was future potential for slippage.