Thanks for letting us know that these links were incorrect. I'll get them fixed. Also you can find all of the correct download links at http://examples.oreilly.com/9780596154240/.
Here are the files for chapter 13:
- Ch13-1_Mars Investig..>
- Ch13-3_Mars Investig..>
- Ch13-4_Mars Investig..>
Please let us know if you need anything else.
O'Reilly Media, Inc.