A Soviet scientist says that despite the delay in U.S. space exploration caused by the Challenger disaster, his country is not ahead in space.

Albert Galeev, co-chairman of the U.S.S.R. Space Research Institute, said Monday that the Soviets have taken advantage of the two years that the United States has not been able to launch satellites easily, but he said both countries could learn from the other.We never have had the illusion that we were ahead, said Galeev at a news conference at the National Aeronautics and Space Administration.

Temporarily, you've lost launch capability, but if you take into account the satellites waiting to be launched, the understanding is that you'll easily catch up, he said.

The United States has not had regular space launches since Challenger exploded and killed its seven crew members on Jan. 28, 1986. Since then, the space shuttle fleet, which was the main U.S. launch system, has been grounded. Flights are scheduled to resume in August.

We took advantage of this delay, said Galeev. We are still leading in a few fields.

He noted, however, that the Soviet Union has to launch more satellites

because its equipment is not as durable as American models.

We launch a lot of satellites but their lifetime is shorter, he said. That means we don't get as much data.

A Soviet astronomer, Rashid Sunyaev, also a co-chairman of the U.S.S.R. Space Research Institute, said scientists everywhere keenly felt the Challenger accident.

Challenger was a tragedy for astronomers, he said, because the space telescope is still on the ground.

Sunyaev said astronomers are anxious for the American-made telescope to be placed into orbit and to start bringing back new visions of the universe. The telescope is to be the most powerful astronomy instrument ever placed into space.

In answer to a question, Sunyaev admitted that some of the scientific information gathered by the Soviet space program has been used for military purposes. But he said this can be said of many things learned by scientists.

Even some of the work of Isaac Newton has been used for military purposes, he said. Newton formulated basic principles of gravity and motion.

Galeev and Sunyaev answered questions at a news conference that marked the end of a week of meetings with American colleagues who are members of the U.S.-Soviet joint working groups on astronomy and astrophysics. Representatives of the two spacefaring nations met to work out ways to exchange data from their space science programs.

NASA officials said the working groups arrived at an agreement, but the plan will have to be approved by leaders of the two governments before it is released publicly.