1.   The leaky fluid was the usual -- an oxidizer known as nitrogen tetroxide, a deadly poison that breaks down chemically in the course of combustion to release oxygen.

2.   Mission operations director Randy Stone said National Aeronautics and Space Administration engineers believe the leaking nitrogen tetroxide would not attach to anything and poses no danger.

3.   The first steering thruster to leak, located at the rear of Discovery, began spewing nitrogen tetroxide shortly after Discovery reached orbit Friday.

4.   The failed steering thruster, located at the rear of Discovery, began leaking nitrogen tetroxide shortly after Discovery reached orbit Friday.

5.   The steering jet failed and began leaking nitrogen tetroxide shortly after Discovery reached orbit early Friday.

6.   Discovery began leaking nitrogen tetroxide from a steering thruster shortly after its launch Friday, and the Russians are nervous that the fuel could damage their space station.

7.   Discovery began leaking nitrogen tetroxide from a steering thruster shortly after its launch on Friday, and the Russians are nervous that the fuel could damage their space station.

8.   The gas, nitrogen tetroxide, escaped Monday from a railway car parked at the Gaylord Chemical Co., sending an orange cloud of fumes spreading around the facility.