While most public attention is focused on America's first woman astronaut, the greater significance of Saturday's scheduled space shuttle flight may be its international flavor.

Besides Sally K. Ride, the shuttle Challenger is to carry Canadian and Indonesian communications satellites for deployment in orbit by its five-member crew and a 3,500-pound instrument package built in West Germany and housing 11 experiments paid for by the West German government.

The instrument package is to be moved around the shuttle's cargo bay, placed outside the bay and then retrieved by the shuttle's 50-foot-long robot arm, developed and built in Canada and operated by Ride.

Such international cooperation on the seventh shuttle flight comes amid a quickening of international competition in space. That was emphasized today in French Guiana where two satellites were launched into orbit by the Ariane rocket of the European Space Agency, a French-led partnership of 10 West European nations.

Neither the United States nor the ESA has kept secret their earnest competition for the world's commercial space business, expected to grow 20 percent a year for the next 20 years.

Astronauts Robert L. Crippen, Frederick H. Hauck, John M. Fabian, Norman E. Thagard and Ride spent today doing aerobatics in T38 supersonic jets to grow more accustomed to weightlessness they will encounter during their planned six days in orbit.

The countdown for Challenger's scheduled launch at 7:33 a.m. EDT Saturday continued to move with few hitches as launch crews quickly put to rest the only difficulties.

Technicians opened Challenger's cargo-bay doors and verified that cables used for ejecting the two communications satellites were connected properly after an outside check suggested that they were not. Technicians also confirmed that an onboard device called the "master events controller" was behaving properly after a false signal suggested otherwise.

The master events controller serves in the early minutes of flight to jettison the shuttle's two solid rocket motors and the huge external fuel tank that feeds liquid hydrogen to the three main engines.

The astronauts' first task Saturday will be deployment of a third-generation communications satellite called Anik-C for Telesat, the Canadian communications company.

Anik, which means "little brother" in Eskimo, is to be targeted for a spot over the equator that places it on a direct line to the Canadian province of Alberta. It is to serve as a switchboard in space for television, telex and telephone calls for all of North America.

Nothing better illustrates the reason for rapid growth of worldwide communications-satellite traffic than Sunday's scheduled deployment of a second-generation communications satellite called Palapa-B. Freely translated from the Indonesian, the word palapa means "the fruit of effort."

Indonesia has two Palapa-A satellites that were orbited by U.S. rockets and have been serving Indonesia, Singapore, Thailand, the Philippines and Malaysia. Palapa-B, twice the size of the earlier satellites, will allow television and telephone traffic among the southeast Asian nations to grow 10 percent to 15 percent a year.

There are only 560,000 telephones for 147 million Indonesians inhabiting more than 6,000 islands that extend 3,200 miles from east to west. The new satellite could put telephones into the homes of as many as 1 million more persons in the next 10 years.

"This is why communications-satellite technology is so important to us," Hartadi Asturi, Palapa project manager for the Indonesian government, told a news conference today. "The best solution for us to solve our communications difficulties is to use the advanced technology of satellites."