CAPE CANAVERAL--Five astronauts blasted-off yesterday morning in the space shuttle Discovery, ready to deliver a $100 million satellite to orbit on the delayed start of an ambitious 1989 launch schedule aimed at putting America "back in the business of space."

Besides the satellite, which will complete a vital communications network, the shuttle is carrying four crippled white rats and 32 chicken eggs among the scientific experiments to be studied during the five-day mission.

The weather forecast--clear skies and mild temperatures--was favorable for launch. Only the possibility of strong high-altitude winds gave any concern, and NASA officials said wind conditions at midnight were acceptable.

Commander Michael L. Coats and his crew were awakened at 3:16 a.m. and, in a surprise, showed up for breakfast wearing business suits and ties. Fine china and candles adorned the table for the steak and eggs feast.

Wearing the suits instead of the normal casual wear apparently was a tongue-in-cheek response to word that NASA was trying to curb astronauts' penchant for fun. Officials reportedly were annoyed by a televised show two missions ago when the crew floated through the shuttle cabin wearing colorful Hawaiian shirts.

Following breakfast, the Coats crew donned flight suits, rode a special van to launch pad 39B and began boarding the $1.5 billion spaceship cabin at about 5:30 a.m.

Flying with the 43-year-old Navy captain are Air Force Col. John E. Blaha, 46, the pilot; Marine Cols. James F. Buchli, 43, and Robert C. Springer, 46 and Dr. James M. Bagian, 36, a physician. Coats and Buchli have flown on previous shuttle flights.

Discovery's launch is the 28th for the shuttle program and the third since the Challenger explosion killed seven astronauts on January 28, 1986.

Shuttle chief Richard Truly said the success of this mission is "absolutely vital" to NASA's continued recovery from the Challenger accident and the agency's move toward safe, routine, monthly shuttle launches by 1992.

Six hours after liftoff, Springer and Bagian were to deploy the 24-ton Tracking and Data Relay Satellite. It will then be carried by its own rocket to a 22,300-mile-high orbit to join two older satellites and complete an orbiting network essential for communicating with future space shuttles and with science and military satellites.

With the new satellite operational, NASA will shut six ground stations at a monthly savings of $3 million.

Coats said the first two post-Challenger flights--by Discovery in September and Atlantis in December--"were important to show that we could fly the space shuttle again after the catastrophe."

"The next step," Coats said, "is to prove we can do it on a regular basis, that we're back in the business of space, to show we're a space-faring nation again."

The mission is filled with scientific experiments. The rats, with chips of bone cut from their legs, are to be studied to determine how well broken bones heal in the weightlessness of space.

The animals will be compared with a ground control group of four rats. Researchers believe healing will be slower in space because astronauts have suffered loss of calcium during flights.

The issue is an important step toward learning how well a broken human bone might mend during long flights aboard a space station or on a trip to Mars.

Also aboard is a special 70-millimeter IMAX camera to photograph environmentally-deteriorating areas of the Earth.

"They're trying to produce a movie that shows the Earth as a very fragile thing in the universe and that maybe everybody on Earth ought to pay a little attention to not destroying it," Blaha said in a recent interview.

The astronauts also will conduct experiments to determine the effects of weightlessness on plant cell division, the growth of protein crystals and the development of chicken embryos.

Discovery is to remain in orbit for five days, one hour, seven minutes, landing Saturday at Edwards Air Force Base in California.