The Defense Department and NASA yesterday announced plans to cloak next month's space-shuttle mission in unprecedented secrecy to conceal from the Soviets the nature of the ship's military satellite cargo.

News articles that "speculate" on the secret payload will be investigated as a breach of national security, said Brig. Gen. Richard F. Abel, Air Force director of public affairs.

Abel told a news conference that future defense-related shuttle missions would be treated "as we do the deployment of air, land and sea forces." About 20 percent of approximately 70 shuttle flights in the next five years are to be military-oriented.

"The more mission information they the Soviets have, the easier it is for them to counter the capabilities of those payloads," the general said.

Reporters pointed out that much information about payloads -- communications satellites, for example -- is now available in technical journals or from congressional hearings.

The shuttle Discovery is scheduled to take off between 1:15 p.m. and 4:15 p.m. EST Jan. 23 from the Kennedy Space Center at Cape Canaveral, but project officials refused to say how long it will remain in orbit and over what areas of Earth it will fly.

For the first time in 46 U.S. manned space flights, the news media will not be able to follow the countdown. Abel said there will be no information released on the military cargo, no press kit, no media access to shuttle television or crew conversations and no interviews with the five-man crew.

Once the shuttle is in orbit, mission commentary will cease. It will resume 16 hours before the planned landing, which will not be announced until then. In between, statements on mission progress will be released every eight hours.

For the first time since the early part of the Gemini program nearly 20 years ago, all communications between the mission-control center and the astronauts in flight will be encrypted and blacked out to the public.

Asked "what reprisals, repercussions would you plan against any reporter who would speculate" about a mission's purpose, Abel said, "I believe that would be something that would be investigated and I would not speculate myself on what would happen." Abel added that a decision on instigating a probe "would depend on the story that was written."

One investigation already is under way, he said.

Abel said future shuttle missions might be completely closed, with no advance information available. He said this would be especially likely of flights from Vandenberg Air Force Base, Calif., where most Defense Department shuttle launches will be conducted, though the initial Vandenberg flight scheduled next October may be opened for coverage.

In other space developments:

* Officials at Cape Canaveral said heavy cloud cover over the Soviet Union in October prevented a unique mapping camera aboard the shuttle Challenger from photographing the site of a major 1950s-era nuclear accident.

The package also included a radar mapper designed to provide insights into geologic structures and processes by generating detailed three-dimensional views of selected ground features. But mechanical problems with an antenna limited scientists to about 20 percent of the planned coverage.

* The $50 million NOAA 7 weather satellite was nearly lost in space this month when a ground controller sent improper commands that set it tumbling out of control, the National Oceanic and Atmospheric Administration confirmed in reponse to a story in Aviation Week magazine. NOAA said the incident had not been publicly announced because the problem was corrected before a statement could be issued.