Analysis of an extensively flawed space shuttle booster proved design changes withstood attempts to mutilate the rocket, Morton Thiokol Inc. officials said.

Engineers incorporated 14 design flaws in the 126-foot rocket booster fired last week. The two-minute test was hailed as a success as NASA and Morton Thiokol prepare for a late September launch of the shuttle Discovery."We've been taking it apart and things look fine," Thiokol spokesman Ed Snow said Thursday. "They disassembled the aft joint. They looked at it and no hot gas had violated the primary O-ring, which was a good sign.

"Things look good so far," Snow said.

A successful firing was critical to resuming space flights. The shuttle fleet has been grounded since January 1986 when a flaw in a booster O-ring allowed hot gases to leak out and ignite the shuttle Challenger's external fuel tanks.

"If everything goes well, we'll have the whole thing completely analyzed and the data reviewed in two to three weeks," Snow said.

Thiokol-built boosters are already installed on Discovery at Cape Canaveral, Fla.