11.   Discovery and its crew of six had to be off the ground within a five-minute span to achieve the most fuel-efficient route to the orbiting Mir station.

12.   Discovery had to be off the ground within five minutes to achieve the most fuel-efficient route to the orbiting Mir station.

13.   Flight controllers need to be at their computers only when there is radio contact with the orbiting Mir station and its crew.

14.   It was detached in February to make room for the arrival of a Soyuz craft carrying a new crew to the orbiting station.

15.   It has put a host of satellites into space and piloted three orbiting stations, including the Mir, and their modules.

16.   More studies also are needed before husbands and wives live together on orbiting stations, he said.

17.   NASA had five minutes to send Discovery on the most fuel-efficient route to the orbiting Mir station.

18.   One U.S.-based company says it is designing orbiting stations for future tourists.

19.   Recent problems have included some satellite launch failures and, notably, frequent breakdowns on the Mir orbiting station.

20.   Russia can launch spacecraft destined for the Mir every three days when the orbiting station passes overhead.