NASA ARES-1 DM-1 Rocket Motor Static Test at ATK, originally uploaded by S. Hurley.
I saw this image on Dick Stafford's rocket dungeon blog. Sorry for using the same image Dick, but you picked a pretty good one :)
Given my post on steel castings yesterday, I thought it might be worth noting that this motor uses a steel casing. Shuttle boosters use a four segment steel casing, and this motor was essentially an extended version of a shuttle booster utilizing five segments. I also read on the Arocket list this morning that the casing sections used for this test were actually flown on STS-1 and have 48 missions on them. I was a little sceptical but I found this article on the NASA site which states "... the cases used in this Ares I first stage ground test have collectively flown on 48 previous shuttle missions, including STS-1, the very first flight.
The video of this test is awesome and definitely worth watching!