NASA personnel
A list of NASA employees.

Named
McMillan
Shannon O'Donnel

Unnamed

McKinley Rocket Base personnel

NASA students 
These would-be astronauts were in the same NASA class as O'Donnel and McMillan prior to 2000. They came up with the slogan "Next stop, Mars". 

In December 2000, upon reuniting with O'Donnel, former media relations man Gerald Moss asked her if she kept in touch with the others. O'Donnel admitted she didn't. Moss did, however, and had called a few of them the night before, including McMillan. ()

NASA astronaut 

A NASA astronaut using the Manned Maneuvering Unit near the Space Shuttle  with a spacehab module in its cargo hold. ( opening credits)

Unnamed Humans