For an embedded viewer, use this HTML tag instead:
http://docs.google.com/viewer?url=http%3A%2F%2Fwww.nasa.gov%2Fpdf%2F420302main_sts130_press_kit.pdf
Google Docs - Viewer
"Use Google Docs to quickly view documents online without leaving your browser.
Enter a document URL below to generate a link to view it "
http://docs.google.com/viewer
Official Google Docs Blog: View online files using the Google Docs Viewer
http://googledocs.blogspot.com/2009/09/view-online-files-using-google-docs.html
「Google Docs Viewer」で、PDFなどブログへ埋め込み表示可能に -INTERNET Watch
http://internet.watch.impress.co.jp/docs/news/20090925_317553.html
