Congressmen, teachers and Saudi princes will no longer be invited by NASA to be passengers on the space shuttle under a new policy that emphasizes completing the recovery from the Challenger accident in which two non-astronauts were killed.

The space agency announced a new category of "space flight participants" and said, at the same time, that flight opportunities for them "are not available at this time."Before the Challenger exploded on liftoff Jan. 28, 1986, NASA had given minimum training to a senator, a member of the House of Representatives, a Saudi Arabian prince and Christa McAuliffe, the first "Teacher in Space." Mrs. McAuliffe was killed along with industrial engineer Gregory Jarvis and five astronauts.

"The Challenger accident marked a major change in the U.S. outlook and policies with respect to the flight of other than NASA astronauts," the National Aeronautics and Space Administration said in the policy statement Thursday.

At the time of the Challenger explosion, the process of choosing a reporter to fly on the shuttle was in its final stages. Committees had winnowed down thousands of applications to 40.

When the shuttle does begin flying non-essential passengers again, NASA said, a teacher will be the first.

The agency said that for now, flight opportunities generally will be limited to professional astronauts and payload specialists essential for mission requirements.

Sen. Jake Garn, R-Utah, flew on the shuttle in April 1985 and Rep. Bill Nelson, D-Fla., was aboard in January 1986, at the invitation of NASA's administrator.

In 1985, shuttle passengers included Sultan Al-Saud of Saudi Arabia and Rodolfo Neri Vela, a Mexican. They were aboard, NASA said, to "observe" the launches of the Arabsat and Morelos-B communications satellites for their countries.