A report on the space shuttle yesterday incorrectly identified Astronaut Sherwood C. Spring's branch of the armed forces. He is a lieutenant colonel in the Army.

Looking like the first ironworkers in space, two space-suited astronauts stepped into the cargo bay of the space shuttle Atlantis last night and practiced construction techniques that will be needed to build a permanent orbiting space station 230 miles above the Earth.

Astronauts Jerry L. Ross, an Air Force major, and Sherwood C. Spring, an Army lieutenant colonel, took 93 aluminum struts and 33 joints and snapped them into place to erect a 45-foot-high tower in a little more than 40 minutes. After breaking down the tower and stowing the parts, they assembled a 400-pound inverted pyramid out of six 12-foot-long aluminum beams before punching out on the first construction job ever tried in the weightlessness of space.

Eight times they built the pyramid and eight times they broke it down, twice more than scheduled and in less time than they were given for six.

By the end of their task, the two astronauts were assembling the pyramid in nine minutes and breaking it down in less than six minutes -- three minutes faster than their first assembly and disassembly.

At 9:30 last night, they had done in four hours a job they were given more than five to complete.

"Need any space stations you want built? Condos?" Spring asked Houston's Mission Control Center while holding a sign that read: "Ace Construction Co."

Television views at the NASA headquarters here showed the astronauts trading places twice while they worked. They appeared in almost complete control of a job that had never been done before in space, where objects move in any direction at the slightest touch.

The only complaint came from Ross, who said that his gloved hands were sweating and that he was using too much oxygen.

When they had finished assembling the six requested pyramids, they were told to take a break by astronaut David C. Leestma in Houston. "I'd be willing to do at least one more," Ross said. "It feels good to do some good hard work." So he and Spring went at it and did two more.

The astronauts, working in daylight and darkness as they circled the Earth almost three times, said they found the tasks a little harder when under floodlights on the dark side of the planet.

"It's like working in your garage without many lights on," Ross said, "but we've all done that before."

When they built the tower, Ross and Spring faced each other in fixed positions, anchored with foot restraints. After putting together one of the tower bays, they slid it upward on guide rails to start work on the next bay.

"It's not coming down as easy as it went up," Ross said when they began breaking down the tower. "It kind of freezes for a minute but once you get it going it moves along real good."

"You're looking great," Atlantis pilot Bryan D. O'Connor said from inside the cockpit. "You guys almost look like you know what you're doing out there."

Once, Spring hit his feet against the tower, and once Ross hit a switch with his hand that turned on an outside light by mistake. Those were the only "accidents" either astronaut had during the exercise, but they triggered a warning from Atlantis Commander Brewster H. Shaw Jr.

"You guys are going great but just remember to be careful," Shaw said from the cockpit. "The way that thing shakes up there, it's not going to be easy to chase anything down if it breaks loose."

When constructing the pyramid, Ross and Spring came out of their foot restraints and attached themselves to tethers so they could float freely around the cargo bay. Ross stayed near the cargo bay floor while Spring floated about 12 feet above the floor. It made Spring look like a trapeze artist but it put more of the workload on Ross, who had to hand up the 12-foot metal beams to Spring.

"We're showing your oxygen at 57 percent and Spring at 72 percent," O'Connor said from the cockpit. "Maybe it's time you switched places."

"I've been stoking pretty good on this one, Bryan," Ross snapped while Spring laughed at his partner's discomfort.

The two crewmen also did a little Earth-gazing.

Said Spring: "I can see the whole world just looking in your visor." Replied Ross: "I see the same thing in yours."