I'm not taking a stand on this one but there is a theory that NASA has faked at least some of the missions to Mars. Here's some stuff about it.

http://www.youtube.com/watch?v=QH7vN3oO1Zw
http://www.youtube.com/watch?v=FlUPnNiG81k
http://es.youtube.com/watch?v=rM0bHAXsRio
http://es.youtube.com/watch?v=nHdvAiz8yUw
http://es.youtube.com/watch?v=7fNbnXmV1CQ
http://es.youtube.com/watch?v=-J_cMoQ_SzE
http://es.youtube.com/watch?v=NsKX9WPpWRg

http://es.youtube.com/watch?v=0RgmjDJdvV0

I don't rule it out considering all the other lies the government tells us. I don't have the science background to verify anything though so I'm going to sit on the fence. If it turns out that they weren't faked, I won't be disappointed. I'll be happy.