Washington — The pace of the arms race in space is accelerating noticeably, fueled in part by high-octane political debate here and abroad. The United States technological lead demonstrated in Sunday's antiballistic missile test is important. For the first time, it was shown that a rocket can intercept and destroy an incoming warhead. But the timing of the event and of other activities in Washington, Moscow, and Geneva this week is - for the moment , at least - receiving greater attention.
Senators yesterday were briefed in secret on Soviet capabilities to attack US satellites with ground-based lasers and other devices. Across town Tuesday, Democratic National Committee chairman Charles T. Manatt announced his party's unanimity in opposing the Reagan administration on space weaponry.
In Geneva, Japanese Foreign Minister Shintaro Abe told the opening session of the 40-nation disarmament conference that both superpowers should halt the arms race in space. And US officials continued to explain why they could not accept Soviet leader Konstantin Chernenko's call Monday for a ban on antisatellite (ASAT) weapons.
Most of these events are keyed to this week's Senate debate on the 1985 defense budget, which includes large sums for antisatellite and strategic defense programs.
The administration is trying to head off reductions in such funds and restrictions on weapons testing. Pentagon officials stress that the Soviet Union now has the capability to attack US satellites. And they point out that the Soviets have the world's only antiballistic missile system, a rocket armed with a nuclear warhead that doesn't have to intercept an incoming warhead, only explode near it. Defense and intelligence sources also warn that the Soviet Union may already have begun using ground-based lasers to interfere with the operation of US satellites.
(Aviation Week & Space Technology reports this week that the USSR is developing a large, manned space station to be defended in orbit by missiles and lasers.)
Critics charge that existing Soviet ASAT and missile-defense systems are relatively unsophisticated and do not pose much of a threat. The United States, they say, is about to ratchet up the arms race in space by testing much more advanced systems that could make arms control impossible.
The US Air Force recently launched its first ASAT weapon, a small rocket carried by an F-15 fighter. The next launch will test the missile's homing device against the light of a star, and the third test (against a target balloon in space) is scheduled for this fall.
The technologies involved in antisatellite devices and ''Star Wars'' systems to defend against enemy warheads are closely related. They both have to do with detecting and intercepting small objects in space with pinpoint accuracy and precise timing.
While the Soviet Union has made advances here, the United States is ahead in such technologies. This fact, together with the extreme arms control difficulties presented by space weapons, is behind the debate over whether to proceed militarily into what Foreign Minister Abe called ''the last remaining frontier for mankind.''
The administration plans to spend $26 billion over the next five years on what it calls its ''strategic defense initiative.'' It is particularly wary of any restrictions on ASAT testing - whether imposed by Congress or proposed by Moscow - because this would hamper efforts to develop a defense against Soviet warheads.
This same thinking is behind congressional efforts to halt such testing. Lawmakers last year adopted a Senate amendment barring ASAT tests against targets in space as long as Moscow continues its declared moratorium on such testing.
The House recently voted to continue this moratorium on ASAT testing and also to cut the administration's request for $1.7 billion in ballistic missile defense funding by $407 million. Administration supporters in the Senate are fighting the ASAT moratorium this week. They also hope to approve a larger sum than the House for ''Star Wars'' defense research-and-development appropriations in 1985.
Pentagon officials this week termed Sunday's antimissile test ''a major breakthrough'' that should prove to skeptics the feasibility of warding off nuclear attack. Others are not so sure, however.
The Union of Concerned Scientists and others say a nuclear attack would include thousands of warheads, plus tens - and perhaps hundreds - of thousands of decoys. It would be easier, critics say, to build more warheads than it would be to try to shoot them down.
Others fear that pushing ahead with space-based missile defenses would undercut the Anti-Ballistic Missile (ABM) Treaty of 1972. A ''National Campaign To Save the ABM Treaty'' was announced Tuesday. Members of the campaign include many notable political, military, and arms control figures, including Jimmy Carter, McGeorge Bundy, William Colby, Dean Rusk, Edmund Muskie, Maxwell Taylor, and Paul Warnke.