The Soviet Union, in a treaty proposal for outer space with earthbound implications, may be offering its first specific concession to Reagan administration policy on arms control.
The apparent Soviet overture, in a draft of the Soviet space proposal published here Aug. 12, concerns the issue of verification of arms-control agreements.
New US arms negotiator Eugene Rostow has said the Soviets must be more forthcoming with relevant arms information, and that Kremlin willingness to cooperate in this sphere could be "a litmus test" for further negotiations.
Mr. Rostow has suggested that verification of any future arms accord with the Soviets must go beyond mere "national technical means," arms-control jargon for each side's satellites and spy planes.
Although mutual "understandings" and "agreed statements" attached to the still unratified SALT II accord envisage an exchange of information in some areas, the main body of the accord terms such a process "voluntary" and limits verification to "national technical means."
An "understanding" appended to the agreed definition of "heavy bombers" in the treaty says only that, in this area, the signatories "may take, as appropriate, cooperative measures contributing to the effectiveness of verification by national technical means."
The new Soviet proposal on "demilitarization" of outer space is seen by some foreign analysts here as a signal that the Kremlin is ready to consider Reagan administration concerns over arms-control verification.
The timing of the proposal is also viewed as a possible sign of a continued Soviet search for early arms talks, despite the recent US decision to produce the neutron weapon.
As a space treaty, diplomats here say, the Soviet proposal is almost certainly a nonstarter, a clear effort to get the Americans to swear off military uses for the new space shuttle.
The proposal's three-paragraph article on verification, however, may have more farreaching implications.
The first two paragraphs are virtually word-for-word reproductions of the verification clause in the SALT II accord--providing for use of "national technical means" and binding the signatories not to interfere with such information-gathering.
But in the final paragraph, the space proposal breaks with SALT II. The SALT accord barred "deliberate concealment . . . which impedes verification by national technical means."
The draft space treaty says:
"To help carry out the aims and provisions of the present treaty, the participating states will, in the event it is necessary, consult with each other , make inquiries, and furnish information related to such inquiries."
The wording remained vague and, unsurprisingly, did not seem to suggest that the traditionally secretive Soviets were ready to throw open their military complex to prying US eyes.
Diplomats also noted that some earlier arms accords--like the 1974 Nixon-Brezhnev agreement on banning nuclear tests--provided for some exchange of information.
But the information clause in the space proposal was markedly less restrictive. And it was the Soviet's own wording, not the product of negotiation with US officials.
The initial impression here was that the Soviet draft space treaty was meant to telegraph willingness, at least, to consider eventual compromise on verification of arms accords with Mr. Reagan.
This impression was strengthened by the fact that the space proposal:
* Came amid public stress by the administration on the need for stronger verification measures.
* Pointedly borrowed SALT II'S wording for much of the verification article.
The Soviet proposal did not, meanwhile, suggest any early overall improvement in increasingly strained superpower relations.
The Soviets continue to fume over Mr. Reagan's decision on the neutron warhead and have been hinting they may now produce one of their own.
The space proposal also seemed to hint that Moscow, despite frequent public denials, might be developing a response to the US shuttle craft.
The draft treaty spoke of "reusable spacecraft, whether of the present type, or other types that participating states [in the treaty] might obtain in the future."