(Reuters) - Boeing and Lockheed Martin's joint venture, United Launch Alliance, said on Friday its Vulcan rocket successfully launched its second mission, in what is a crucial step to receive certification for Pentagon missions.

Vulcan, developed to replace ULA's workhorse Atlas V rocket and rival the reusable Falcon 9 from Elon Musk's SpaceX, took off from the Cape Canaveral Space Force Station in Florida.

It had successfully debuted in January this year.

With the launch, ULA is looking to fulfill flight test obligations and complete its certification process with the U.S. Space Force, which requires two verification flights before it can put national security payloads aboard.

ULA said the U.S. Space Force - a key customer for Vulcan - will review the data and compare it to ULA's first certification mission to ensure that the vehicle performed as expected, before it can be certified.