It's a rocket.
Here's the caption to the photo, which can be found in NASA's image galleries.
Good work for the betterment of mankind.
A welder at NASA's Glenn Research Center (GRC) grinds welds on an Ares I-X rocket segment being readied for shipment to Kennedy Space Center. Ares I is part of the next generation of launch vehicles that will return humans to the moon and later take them to Mars and other destinations. Ares I is an in-line, two-stage rocket configuration topped by the Orion crew vehicle and its launch abort system. In addition to the vehicle's primary mission -- carrying crews of four to six astronauts to Earth orbit -- Ares I may also use its 25-ton payload capacity to deliver resources and supplies to the International Space Station, or to 'park' payloads in orbit for retrieval by other spacecraft bound for the moon or other destinations.
The Ares I-X is scheduled for a test launch in 2009. GRC is designing and manufacturing several components of the test rocket, including the upper stage mass simulator and the service module and spacecraft adapter simulators.
Image Credit: NASA/Marvin Smith