The rocket company, jointly owned by Boeing and Lockheed Martin, has been racing to prepare its vehicle to carry military satellites.

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.

United Launch Alliance's Vulcan rocket, under contract for dozens of flights for the US military and Amazon's Kuiper broadband network, lifted off from Florida on its second test flight Friday, suffered an anomaly with one of its strap-on boosters, and still achieved a successful mission, the company said in a statement.