I apologize for the headline, where I carelessly used the term "DNS config" incorrectly. I was hoping instead for the actual explanation for this. The web apps they've deployed for publicizing the Mars landing are extremely well done, and certainly took a tremendous amount of effort and money. They obviously have a huge commitment to a strong and polished web presence.

So really it's mystifying to me that they leave "nasa.gov" unreachable.

When you say "the two hostnames point at two pieces of infrastructure", "nasa.gov" only has MX records. There isn't existing "nasa.gov" infrastructure, at least on the open internet, to be redirected.

Since they do have to host "nasa.gov" separately due to the akamai thing, we're talking a moderate set of EC2 instances which do nothing more than send a 302 redirect including path info to www.nasa.gov. It's a couple of lines of mod_rewrite. The load on the instances, which could be high due to many visitors, would still be limited by the fact that unique visitors would only hit it once, or perhaps a small initial handful of times, per session. The total amount of bandwidth for 302 redirects is very small.

It's not zero effort, and requires some hosting. But I'm not yet clear on why the "implementation and ongoing operational costs" aren't microscopic compared to those which they spend on an app like the "Eyes on the Solar System" application (http://eyes.nasa.gov/).