Living in Space - Book 2 Levels D, E, and F for grades 4, 5, 6 Part of Operation Liftoff, this 54 page educator's guide is filled with space activities that also focus on math and science. Note: file sizes are larger for this guide because the book was scanned into the computer - and pages are all graphics files. Download the units (all files are PDF): Download the entire Living in Space-Book 2 (54 pages - 11 MB) Last modified November 2, 2004