WASHINGTON, Oct. 16 — The space shuttle Discovery will launch on schedule next Tuesday even though questions remain about small defects on heat shield panels along its wings, NASA managers said Tuesday.

After an all-day meeting in which engineers debated technical issues that could affect the mission, managers decided to keep the shuttle’s Oct. 23 launching date for a mission that will take a key component to the International Space Station.

N. Wayne Hale Jr., director of the space shuttle program, said there were still questions about the degrading of a coating on 3 of 44 panels on the leading edges of the Discovery’s wings. While not fully understood, Mr. Hale said, the problem appeared to be an acceptable risk. 

Noting that the shuttle is an experimental vehicle that should never be considered completely safe to fly, Mr. Hale said managers who heard all the arguments voted to fly on schedule, although some had a few reservations. Mr. Hale said the decision was not made to keep the shuttle launching program on schedule, a criticism of the space agency that was voiced by investigators after the 2003 Columbia accident.

“We are not going to let schedule drive us into making a decision,” Mr. Hale said at a news conference late Tuesday after the meeting at the Kennedy Space Center in Florida. “The preponderance of evidence, in my mind, is that we have an acceptable risk to go fly.”

The leading edges of a shuttle’s wings must withstand some of the most searing heat of re-entry, with temperatures that reach up to 3,000 degrees. NASA has been particularly concerned about the vehicle’s heat shield since the Columbia and its crew of seven were lost because of unnoticed damage that occurred during launching when a piece of insulating foam struck and punched a hole in a panel.

A group of engineers at NASA’s Engineering Safety Center, which was set up after the Columbia disaster to provide independent advice on safety issues, had recommended replacing three of the Discovery’s wing panels because a new test suggested that slight degradation of part of their surface could cause a panel to fail during a flight.

Mr. Hale said agency managers decided to proceed because of uncertainty about the meaning of the new test results and because shuttle crew members can now inspect and repair some heat shield damage during a mission. Replacing the panels would have required removing the Discovery from the launching pad, delaying its next flight by 60 days when there was no certainty of a genuine problem, he said.