NASA explain that thing in this picture is:
Four RS-25 engines, like the one pictured here undergoing a hot-fire test, will power the core stage of NASA's Space Launch System (SLS) -- NASA's new heavy-lift launch vehicle. Towering more than 200 feet tall with a diameter of 27.6 feet, the core stage will store cryogenic liquid hydrogen and liquid oxygen that will feed the vehicle’s RS-25 engines.
SLS will be the most powerful rocket in the world with the greatest capacity of any launch system ever built to support any destination, any payload and any mission, including NASA's plans to send humans to a captured and relocated asteroid. The 70-metric-ton (77-ton) configuration will stand at 321 feet -- taller than the Statue of Liberty. Image Credit: Aerojet Rocketdyne.
This picture was taken from NASA's Instagram account, posted on September 14th 2013.
BIG NASA'S PROJECT
BIG NASA'S PROJECT
