The space shuttle Columbia thundered into orbit at 11 a.m. today, the first time the spaceliner had lifted off on schedule in its four test flights, but the shot was marred by the loss of two reusable solid rocket boosters in 3,100 feet of water in the Atlantic.

The Columbia, carrying astronauts Thomas K. (Ken) Mattingly and Henry W. Hartsfield, had a picture-perfect liftoff. But when the 150-foot-tall rocket motors fell away from Columbia's fuselage, television from chase planes of their separation did not show any of the three main parachutes on either booster engine opening up. If none of the parachutes opened, the two boosters would have fallen 80 miles with only their stabilizing drogue chutes open to break their fall 160 miles east of Cape Canaveral.

Though the sounds of their sonar transponders could be heard on the surface, there was no sign of any of the six main chutes or either of the two solid rocket boosters, which cost $25 million each. This was the first time in four flights that the recoverable and reusable solid rocket engines had been lost to the ocean.

When the boosters were recovered at sea on the first three flights, their nozzles were plugged and the boosters towed back to the Kennedy Space Center by recovery ships. Once out of the water, the boosters were disassembled and washed with distilled water to offset any salt water corrosion.

The motors, igniters and nozzles of the first six solid boosters used by Columbia were shipped back to Thiokol Chemical Corp. in Utah where the motors are rebuilt at a cost of $7 million apiece. Until today, this has been a procedure that has saved the National Aeronautics and Space Administration $36 million a flight for the first three flights.

Easily the most expensive mishap in four shuttle test flights, the $50 million mistake almost overshadowed the nearly flawless flight into orbit of the 100-ton spaceliner. About the only thing outside of the loss of the boosters that was not perfect today was the shuttle's orbital altitude. Columbia ended up in space today a little lower than Mattingly and Hartsfield wanted.

Today's flight left the earth right on time at 11 a.m. EDT, the first flight that didn't suffer some delay at liftoff.

"The launch team is maturing," said launch operations director Alfred D. O'Hara. "The people in the firing room are on their toes, it's just one of the assets we have down here at KSC the Kennedy Space Center ."

On time as it was, today's launch was not without its anxiety attacks in the hours before liftoff. Hail the size of golf balls fell in the middle of a one-hour thunderstorm on the launch pad on Saturday night, denting about 400 of the black protective tiles on the undersides of the shuttle's wings, speed brake and tail.

"There were about 200 small dings on the right wing," O'Hara said today. "I think that we could have gone today without making any repairs but we decided we would fix those spots that we could get to last night."

Moving the circular steel service structure back in close to Columbia Saturday night, 30 workmen quickly erected scaffolds on a gantry deck at wing level. About 15 technicians wearing safety belts wiped down the nicked tiles with alcohol, then applied a glue-like hardening chemical to the white-specked nicks to smooth out and strengthen the tiles.

Workmen had repaired the tiles by early this morning. Shuttle engineers were worried that so much rain had fallen on the shuttle Saturday night and water soaked far enough into the tiles that the morning sun would not be enough to dry them out. Engineers devised a scheme to have Mattingly and Hartsfield point Columbia's bottom at the sun once they were in orbit and bake it there for the next 10 hours to dry out all the tiles.

"It's not that we don't want to carry wet tiles in space," one shuttle engineer explained. "The tiles might freeze on the night side of the earth and ice could damage those tiles."

By 5 p.m. today, Mattingly and Hartsfield had maneuvered the spaceliner to a point where they were ready to soak its bottom in the sun. Said Mattingly: "Things look pretty nice here. We've got the cargo bay doors open and we're setting up shop."

Setting up shop for Mattingly and Hartsfield also meant the start of the first secret military mission to be flown in orbit by the civilian NASA. By 4 p.m., Mattingly and Hartsfield had powered up 2,000 pounds of instruments had been placed in the cargo bay by the Air Force, instruments that are sending whatever measurements they are making through the mission control center at the Johnson Space Center in Houston to an Air Force control center in Sunnyvale, Calif.

"Is the line to Sunnyvale working?" astronaut David Griggs asked absently over the shuttle's radio link. In a moment a voice replied that it was.

While the Air Force refuses to identify its cargo, it is an open secret that the instruments include an infrared telescope so sensitive it can pick out engine exhausts of high flying aircraft and tell whether they are the exhausts of Soviet or American planes. The instruments also include an ultraviolet telescope and a new space sextant that are being groomed to navigate spy satellites through space on their own without being commanded in orbit from the ground.

While Columbia's classified cargo is in the spotlight, its testing is not by any means the major objective of the flight. The seven days Mattingly and Hartsfield plan to be in orbit are to wring out whatever wrinkles are in the spaceliner that were not ironed out on the first three flights.

Once the astronauts bake the bottom of the spaceliner to dry out the tiles, they will fly Columbia with its tail at the sun for 66 hours, then with its cargo bay at the sun for five hours and then back with its bottom in the sun for 23 more hours. This will be done to find out how the heat of the sun warms the spacecraft and permits its countless electronic operations to work.

Mattingly and Hartsfield were approaching their seven-day flight in a methodical manner. Said Mattingly: "We are here for a week so we might as well just move into these things real slow right now."