HUNTSVILLE, Ala. (AP) — North Alabama has a huge new structure on its landscape.

NASA says construction work is finished in Huntsville on a 221-foot-tall, twin-tower stand that will be used to test hardware for the space agency’s new rocket.

The massive structure is located at Marshall Space Flight Center, where engineers are installing equipment needed to test the largest fuel tank that will be part of the Space Launch System rocket.

The stand will simulate the stresses of flight by pushing, pulling and bending a test fuel tank. Such tanks will eventually be part of rockets that are intended to take astronauts into deep space.

Huge towers are a familiar sight at Marshall, where test stands dating back to the early days of the U.S. space program still stand.