(Adds details about launch and satellite)
By Irene Klotz
CAPE CANAVERAL, Fla., Oct 2 (Reuters) - An unmanned Atlas 5 rocket blasted off from a seaside launch pad in Florida on Friday to put a communications satellite into orbit for Mexico.
The 195-foot (59-meter) tall rocket, built and flown by United Launch Alliance, a partnership of Lockheed Martin and Boeing, lifted off at 6:28 a.m. EDT from Cape Canaveral Air Force Station. Launch was delayed 20 minutes to allow time for a wayward boat to clear away from the rocket's flight safety zone.
Perched on top of the rocket was the Boeing-built Morelos-3 communications satellite, a duplicate of a spacecraft lost during a Russian Proton rocket launch in May.
It was the 100th launch for ULA since its formation in 2006, all of which have been successful.
Morelos-3 was due to be put into orbit 22,300 miles (35,888 km) above Earth about three hours after liftoff. The satellite is designed to provide cellular voice, data, Internet and video services for Mexican national security and civilian services over the next 15 years.
Mexico is paying Boeing about $1 billion for a three-satellite system, collectively known as MEXSAT. The contract, announced in 2010, includes two ground sites, network operations systems and user terminals.
The launch marked a rare commercial mission for ULA, which typically flies U.S. military and NASA science missions.
ULA is designing a new rocket, called Vulcan, that it says will be less expensive to build and fly. The company faces its first competition for the U.S. military's launch business, with privately owned SpaceX now certified to fly defense and national security satellites on its Falcon 9 rocket.
ULA also is wrestling with supply issues, as the RD-180 Russian rocket engines that power its workhorse Atlas 5 launcher have been banned for use on military missions. U.S. lawmakers enacted the ban last year after Russia's invasion of Ukraine.
That could leave SpaceX as the sole bidder for a 2018 Global Positioning System satellite launch. An Air Force solicitation for launch services was released on Wednesday, with proposals due Nov. 16.
ULA and Air Force officials are seeking a partial exemption to the RD-180 engine ban to keep the Atlas 5 available for military missions until Vulcan, with its U.S. engines, is ready to fly.
ULA is reviewing the GPS launch solicitation and monitoring congressional proposals to allow additional RD-180 imports before deciding on whether to bid for the work, said spokeswoman Jessica Rye. (Reporting by Irene Klotz, editing by Larry King)