An administration task force is expected to recommend to President Reagan that the space shuttle no longer compete to launch commercial and foreign satellites as part of a major policy shift to make room for the backlog of military payloads, according to administration sources.

The recommendation, which is bitterly opposed by the National Aeronautics and Space Administration and commercial satellite companies, would effectively end the space agency's effort to make the shuttle an economically viable space transportation system that would "pay for itself" by launching private satellites for a fee.

The National Security Council's Senior Interagency Group on Space (SIG) has tentatively decided to include the recommendation as part of a $5 billion to $7 billion space proposal for a new shuttle orbiter and unmanned rockets, known as expendable launch vehicles, for the Air Force, the sources said.

The proposal is being prepared in the wake of the Jan. 28 Challenger shuttle explosion that killed seven astronauts and suspended shuttle launches.

A White House official said not all commercial satellites would be shifted off the shuttle, but that it was likely there would be "a mix" of commercial and military payloads in the future. He said he could not be more precise.

The full NSC is expected to discuss the recommendation this week with Reagan. One official said the group may postpone a decision on financing a new orbiter until the commission headed by former secretary of state William P. Rogers concludes its study of the loss of Challenger.

Some officials also said the group has not yet decided how to handle the commercial customers who are booked for shuttle launches. A special economic policy group task force has been assigned the job of developing a "transition" plan for the companies with satellites waiting to fly aboard the shuttle when flights resume.

The proposal underscores the fundamental changes contemplated in the country's space program as a result of the Challenger disaster as well as the more recent accidents involving Titan and Delta rockets. Ever since the shuttle began flying in 1981, NASA has sold it as a "balanced" vehicle that would carry military, science, and commercial payloads in roughly equal proportions and, in the process, recover a substantial portion of the huge national investment in the fleet from private satellite companies paying fees for launches.

But in order to attract private customers, NASA essentially subsidized them by charging about $30 million a flight, less than half the true cost of putting their payloads into orbit, some officials have argued.

The new policy is being driven by a more immediate need, however, administration officials said. This is the expanding backlog of military satellites, including those needed for Strategic Defense Initiative (SDI) experiments, that will take priority once shuttle flights resume. One administration official said the ultimate "national security" backlog may amount to 75 satellites by the mid-1990s.

"Most of the commercial companies that really want to fly on the shuttle aren't going to get the opportunity anyway," one administration official said. "The backlog is just too big."

In the meantime, the proposal has spread alarm through the commercial satellite industry whose executives said that, because no U.S. company is launching satellites, they will have to turn to the French-owned Ariane rocket or other foreign governments, including Japan or China.

NASA officials said there are 31 satellites booked on the shuttle through 1992, representing about $1 billion in business. These companies have made about $200 million in progress payments to NASA, money that would have to be refunded if the space agency cannot launch the satellites, according to Chester Lee, NASA's director of commercial services.

In another example of the limitations imposed by the loss of the Challenger, NASA yesterday unveiled a scaled-down design for a futuristic $8 billion space station that agency officials said could give the United States a permanent manned presence in space by 1994.

Described by NASA Administrator James C. Fletcher as the "next logical step" after the space shuttle, the football field-size laboratory would be assembled in stages in what one official likened to construction of a huge "tinker toy." Upon completion, it would orbit the earth 290 miles in space, serving as home to a crew of eight astronauts for up to nine months at a time.