The Smithsonian Channel App is available free for iPhone and iPad in the iTunes Music Store inside iTunes. The iPad can put programs through the AppleTV to HDTV vis HDMI cable. I am very happy with my AppleTV v.3 little black box, no Hard Drive.
The Smithsonian Channel is also available in Podcasts. There are 50 episodes. The podcasts would get into the iPad via iTunes syncing.
The new iOS 7+ can screen share between the iPad and the HDTV via ATV, so basically anything on the iPad screen can be on TV.