A federal judge, after listening to 30 minutes of oral argument yesterday, refused to block the Defense Department's first test of a new antisatellite weapon against a target in space, now scheduled for noon today.

The test shot, according to informed sources, will involve an F15 fighter firing a test rocket at an obsolete, 6-year-old Air Force satellite traveling more than 200 miles above Vandenberg Air Force Base, Calif., in a north-to-south polar orbit.

If the system works as designed, it should take about 10 minutes for the infrared homing device carried by the rocket to maneuver into the path of the satellite and destroy it on impact, the sources added.

Ground-based radars at Vandenberg and the North American Air Defense Command in Wyoming will be used ot see if the target satellite is hit.

The test, like the problem-plagued, antisatellite system itself, has provoked controversy in the United States and threats from the Soviet Union.

U.S. critics have argued that the proposed system will trigger a new type of arms race in space. Moscow has said that if the United States holds "tests using antisatellite weapons" against targets in space, it will "consider itself free of its unilateral commitment not to place antisatellite systems in space."

In refusing to enjoin the test, U.S. District Court Judge Norma Holloway Johnson said the issue was political and "should not be determined in this forum." She also said that the plaintiffs, four House members and the Union of Concerned Scientists, had not demonstrated a "substantial likelihood of success" in a full trial if the delay were granted, which is another legal requirement for issuing a postponement order.

The plaintiffs argued that President Reagan has not met a congressional requirement that he certify that he is negotiating "in good faith" to reach an agreement with the Soviet Union on limiting antisatellite weapons.

Reagan, in his Aug. 20 certification to Congress, said the administration "had been unable to date to identify a specific antisatellite proposal" that was verifiable, but that it was "seriously exploring with the USSR arms control arrangements intended to prevent an arms race in space."

The plaintiffs said that this certification "was contrary to fact and reality, not in accod with the statutory requirement, and hence invalid."

Government lawyers yesterday called the lawsuit "frivolous" and said it had "alleged no concrete, personal injury that would entitle them to pursue this action."

The judge picked up that argument, stating in her opinion from the bench that the plaintiffs would not be irreparably harmed "by what they speculate will take place."

Late yesterday, after the judge's opinion had been released, a letter signed by 100 members of Congress was sent to the White House asked Reagan to postpone the antisatellite test until after his Geneva summit meeting with Soviet leader Mikhail Gorbachev Nov. 19-20.

In the Senate, John F. Kerry (D-Mass.) attempted unsuccessfully to attach onto a major immigration bill an amendment to postpone the test until after the summit. The amendment, which would have been meaningless without House approval subsequent signature by the president, was tabled 62 to 34.

The F15-launched antisatellite weapon is not the first such system the United States has developed. In the 1960s, the United States tested and deployed a nuclear antisatellite weapon that was launched atop a Thor intermediate-range missile. The system was based on Johnston Island in the Pacific Ocean.

After the U.S. system was tested, the Soviets developed their own system, consisted of a bomb that was launched into orbit by a giant SS9 Soviet rocket. The bomb, guided by radar, maneuvered close to its target satellite and blew up when it drew near, destroying both devices.

In the 1970s, the U.S. system was retired after the signing of the treaty banning explosions of nuclear weapons in outer space. That left the Soviet Union with the only operational antisatellite weapon.

In 1978, the Carter administration funded the initial development of the F15 system as a bargaining chip for negotiations it hoped would lead to an overall ban on all antisatellite weapons. After talks began with the Soviets in 1979, they quickly bogged down when Moscow's negotiators demanded that the U.S. space shuttle be included as an antisatellite weapon.

All discussions broke off in 1980 after the Soviet invasion of Afghanistan.

But work continued on the F15 system, although at a slow pace since the Air Force wa snot enthusiastic about the program.

The Reagan administration, however, pushed the project, citing the existing Soviet orbiting system as a threat to U.S. security.

The Soviets also sought to upgrade their system since the United States possessed measures that easily jammed the radar guidance of the Soviet weapon. Between the late 1970s and 1982, the Soviets tested a new, infrared-guided version of their orbiting antisatellite weapon six times, and each time it failed.