The blacked-out television wrist camera on the end of the space shuttle's mechanical arm was still dark today, forcing astronauts Jack R. Lousma and C. Gordon Fullerton again to postpone using the arm to lift an instrument out of Columbia's cargo bay.

Although tired after three days of keeping up with their flight plan and trying to fix things that were breaking down, Lousma and Fullerton said they would be ready on Thursday to work the arm without its wrist camera.

They will attempt to raise an 82-pound Plasma Diagnostic Package and move it around the cargo bay in a critical test of the robot arm. The instrument measures the electrical disturbances caused by the spacecraft's instruments and its motion through the electronically charged ionosphere.

"It is really not all that difficult to do," astronaut Hank Hartsfield, who will be the pilot on the next shuttle flight in June, told the crew from the Mission Control Center in Houston. "We did it down here today without the benefit of cameras. You just have to take it a little slower and use your eyeballs a little more."

When the wrist camera went dark on Tuesday, flight directors postponed the first attempt at the critical grappling test. They postponed it again today to give Hartsfield time to devise a technique to do the test without relying on the wrist camera, which serves as the astronauts' eyes whenever the end of the arm is used to fasten onto an instrument or satellite in the cargo bay.

"What you have to do is come in high, use the elbow camera at a sharp angle and do a wrist roll as the next to last step," Hartsfield advised. "Then, all you have to do is drive it right on in and do a grapple."

In full agreement, Lousma and Fullerton went on to extend their robot arm far above the cargo bay and use the television camera on the arm's elbow to transmit the best television ever seen of the earth from 150 miles up in orbit.

Speeding across the United States this afternoon at five miles a second, the astronauts moved the color camera on the arm around like a movie director, sending back a panorama of the country unlike any ever seen.

Starting with Lake Tahoe, the camera never stopped until it ran out of antenna time over the Atlantic Ocean. Viewers saw the Painted Deserts of the west, the snow-covered Rocky Mountains, the checkerboard fields of the Great Plains and the patchwork quilt of the farms of the Middle West, all against the curving blue horizons of the Pacific and Atlantic oceans. "That's fantastic television," astronaut George Nelson called up from Mission Control. "Makes me wish I'd stowed aboard."

"This is good old America, from sea to shining sea, the whole bit," Lousma called back from Columbia. "It really is America, the beautiful."

Elated as he was during the telecast, Lousma spent what could only be described as a bad day. Put simply, Lousma has felt lousy most of the last three days in space.

Not only was he kept awake the last two nights by radio static whose source is thought to be a powerful radar run by the Soviet Union at the eastern edge of the Black Sea, he was still suffering from motion sickness that caused him to avoid eating, take drugs to fight it and vomit at least once.

Apparently, Lousma vomited sometime on Tuesday and began to feel a little better.

Lousma was awakened several times Monday and Tuesday nights when he tried to sleep sitting up in the cockpit with his headset on.

Each time the spacecraft flew north toward the Soviet Union late at night, Lousma heard a loud static whose source probably is the radar that sends a powerful signal across Western Europe from Rostov at the mouth of the River Don, which feeds into the Sea of Azov which then feeds into the Black Sea.

The radar the Soviets operate at Rostov is nicknamed "Woodpecker" by ham radio operators around the world because of the woodpecker-like noise it creates from Spain in the west to parts of China in the east. Sources said it may be the most powerful radar in the world..