The space shuttle Discovery ended its trouble-plagued flight today with a rocky landing and the worst damage in 16 shuttle missions -- a burn-hole in a wing, two failed brakes, two blown tires and at least 123 broken heat-shield tiles.

The first congressional observer in space -- Sen. Jake Garn (R-Utah) -- also seemed a bit the worse for wear. He wobbled down the steps to the runway and had to be helped into a van that took the seven crew members to the dispensary for medical examinations.

"The senator is feeling fine," flight surgeon Donald Stewart said later. "He just took a little time to get his earth legs back."

The damage to Discovery could set back preparations for its next mission, scheduled June 12. The protective tiles -- probably damaged when the shuttle lifted off through rain -- will have to be replaced or repaired.

"There's little question that we suffered more severe damage on this landing than on any other so far," shuttle launch operations director Robert Sieck said this afternoon. "The brake damage and burn hole in our left wing was certainly more severe than any damage of its kind we ever had before."

Despite the damage to Discovery, Sieck said preparations remained on schedule for the launch in 10 days of its sister ship Challenger with a Spacelab module and a crew of seven.

Discovery was troubled even before it left the ground. Its flight was postponed several times, resulting in new crew assignments and new mission tasks. Once in orbit, the crew successfully deployed two communication satellites, but one was dead and could not be revived despite an ingenious effort to activate it by flipping a switch with the shuttle's robot arm.

The trouble continued today when Discovery was waved off its descent for a 7:16 a.m. landing because of rain over Cape Canaveral. One orbit later, it headed down toward Kennedy Space Center.

Discovery Commander Karol J. Bobko was told to land on runway 33 instead of runway 15 because of sun glare from that direction, the north-northeast. Bobko landed with no headwind to slow him, touching down at 231 miles an hour, the fastest any shuttle has landed.

As Discovery rolled down the three-mile concrete runway it encountered a nine-knot crosswind and began veering to the right. Bobko corrected for the wind by braking one side. The strain apparently was too much, and one of the inboard brake assemblies locked. Moments later, the inboard brake assembly on the other side also locked and Discovery began to burn rubber. Blue smoke was clearly visible.

By the time Bobko brought Discovery to a stop using the two remaining assemblies, two tires had blown out with loud reports and Discovery had left a trail of skid marks.

A burn-hole the size of a dinner plate had nearly penetrated the shuttle's left wingtip where a landing flap apparently dislodged several protective tiles.

Sieck said Bobko apparently had no trouble controlling the landing.

Nevertheless, Sieck said he was concerned. "Brake damage we've seen before on previous flights," he said. "Brake failure is something we've never seen."

Sieck said the burn hole in the wing would have been more serious had it been larger. "It's still something to concern us because it burned right through some aluminum structure in the wing. That's never happened before either. But I think it's something we can correct in the next 33 work days."

The crew behaved as if nothing had happened. When Bobko, Garn, Pilot Donald E. Williams, Jeffrey A. Hoffman, F. David Griggs, Margaret Rhea Seddon and Charles D. Walker spoke to well-wishers before leaving for Houston's Johnson Space Center, they did not mention the incidents.

Feeling better by then, Garn, 52, said it had taken him a while to get used to gravity again. "Being in zero G for seven days -- all this weight is a little heavy," he said.