CAPE CANAVERAL, Fla. (AP) — NASA has completed an engine test firing of its moon rocket, after the first attempt in January ended prematurely. This time, the four main engines of the rocket’s core stage remained ignited Thursday for the full eight minutes. On the first test firing, the engines shut down after a minute. The SLS or Space Launch System rocket is what NASA intends to use to send astronauts back to the moon. NASA plans to launch it for the first time sometime in the coming year or so, sending an empty Orion capsule to the moon and back. Officials say they don’t want to commit to a date quite yet.