Subject says it all and read the full story here. http://blog.sucuri.net/2010/10/nasa-web-site-hacked-and-serving-malwarespam.html Check out the update 1: as well which says http://esc.gsfc.nasa.gov/ seems to be hacked as well
Wow Shabbir... the goverment take that very seriously. I'll say in less than 3 months the responsible person for that will get caught. I just looked at the sites,and it seems to me they're using an remote files inclusion with a persistent xss attack. Most likely done by a very sophisticated spam bot.
Once he is caught he should be appointed by NASA to protect those sites rather than prison-ed. Catch me If you Can