_Acknowledgments

The help and advice of the following people is gratefully appreciated:

Doug Beason, USAF; Jim Dorris; Steve Fairchild; Andrew Fraknoi, Astronomical Society of the  Pacific; Charles Ginenthal; Jackie Hogan; Les Johnson, NASA, Marshall Spaceflight Center, Huntsville, AL; Frank Luxem; Melinda Murdock; Jeffrey Slostad; Brent Warner, NASA, Goddard Spaceflight Center, Greenbelt, MD; Betsy Wilcox, USAF