I do some web development, and I see this a lot. For whatever reason (and there are many legitimate possibilities, from restructuring the website to monitoring traffic), they are using a meta redirect:
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<META CONTENT="0;URL=http://www.nasa.gov/mission_pages/station/structure/elements/its.html" HTTP-EQUIV="REFRESH">
It's actually a rather poor method in most cases and generally shouldn't be used. A server-side redirect is really the best way because it doesn't "break the back button" as we say and search engines will update their results.
Essentially, APOD copied a link to a page on the NASA spaceflight site. The link pointed to another NASA spaceflight page, but that page isn't actually where the info is. Probably it was there and was later moved to the NASA main site. To keep viewers who followed a link or bookmarked the page from getting a "404: Page not found" error, they inserted the meta tag that tells the browser to load the page on the NASA main site.
So your browser has actually visited three pages (apod, spaceflight.nasa.gov, and nasa.gov). When you click the back button, it goes back the spaceflight page that still has the meta tag, which causes the browser to once again jump forward. Had they used a server side redirect ("301: permanent redirect" is the best option) your browser would only remember the two pages that actually have information. Unfortunately that requires changing some things on the server instead of adding that one line of code to the intermediate webpage, so they probably did it to keep things quick and organized.
You can doubleclick the back button and it will jump back two pages before the middle page finishes loading. Meta tags aren't recognized until the page loads.
It's partially the APOD author's fault for copying the link (which points to spaceflight.nasa.gov) instead of loading the actual page and copying the address from there (
http://www.nasa.gov).
I do some web development, and I see this a lot. For whatever reason (and there are many legitimate possibilities, from restructuring the website to monitoring traffic), they are using a meta redirect:
[code]<META CONTENT="0;URL=http://www.nasa.gov/mission_pages/station/structure/elements/its.html" HTTP-EQUIV="REFRESH">[/code]
It's actually a rather poor method in most cases and generally shouldn't be used. A server-side redirect is really the best way because it doesn't "break the back button" as we say and search engines will update their results.
Essentially, APOD copied a link to a page on the NASA spaceflight site. The link pointed to another NASA spaceflight page, but that page isn't actually where the info is. Probably it was there and was later moved to the NASA main site. To keep viewers who followed a link or bookmarked the page from getting a "404: Page not found" error, they inserted the meta tag that tells the browser to load the page on the NASA main site.
So your browser has actually visited three pages (apod, spaceflight.nasa.gov, and nasa.gov). When you click the back button, it goes back the spaceflight page that still has the meta tag, which causes the browser to once again jump forward. Had they used a server side redirect ("301: permanent redirect" is the best option) your browser would only remember the two pages that actually have information. Unfortunately that requires changing some things on the server instead of adding that one line of code to the intermediate webpage, so they probably did it to keep things quick and organized.
You can doubleclick the back button and it will jump back two pages before the middle page finishes loading. Meta tags aren't recognized until the page loads.
It's partially the APOD author's fault for copying the link (which points to spaceflight.nasa.gov) instead of loading the actual page and copying the address from there (http://www.nasa.gov).