The final ground test of a space shuttle solid rocket booster ignited at 11:50 a.m. Mountain time in Promontory, Utah. The two-minute firing will help ensure the final four space shuttle missions launch safely.

Photo credit: Ben Cooper/Spaceflight Now

Photo credit: Ben Cooper/Spaceflight Now   Photo credit: Ben Cooper/Spaceflight Now   Photo credit: Ben Cooper/Spaceflight Now   Photo credit: Ben Cooper/Spaceflight Now   Photo credit: Ben Cooper/Spaceflight Now   Photo credit: Ben Cooper/Spaceflight Now   Photo credit: Ben Cooper/Spaceflight Now   Photo credit: Ben Cooper/Spaceflight Now   Photo credit: Ben Cooper/Spaceflight Now   Photo credit: Ben Cooper/Spaceflight Now   Photo credit: Ben Cooper/Spaceflight Now   Photo credit: Ben Cooper/Spaceflight Now