1.   In case of multiple engine failure, the shuttle would not have enough thrust to return to Florida.

2.   NASA officials acknowledge that the shuttle has a limited lifetime.

3.   No shuttle has ever had to use one of the abort sites on the east side of the Atlantic, two in Spain and two in Africa.

4.   The first NASA shuttle had yet to be launched, space was still mysterious and inspiring.

5.   The Discovery shuttle normally has a crew of six, but a seventh space can be easily added for Glenn, officials said.

6.   The shuttle has a return-to-base emergency provision for an aborted launch.

7.   The shuttle has enough electrical power to stay in orbit until Thursday.

8.   The shuttle has two identical cooling systems.

9.   The shuttle will have a five-minute launch window.

10.   If a shuttle has room and is flying anyway, why not load it with as much freight as possible, Black wonders.