* Launch vehicle's main stage booster makes swift return landing
* Landing is the second successful one at sea for SpaceX
* SpaceX intends to reuse rockets to offer cheaper launch services (Adds landing in headline, quotes, further details)
By Irene Klotz
CAPE CANAVERAL, Fla., May 6 (Reuters) - An unmanned SpaceX Falcon 9 rocket blasted off from Florida on Friday to put a communications satellite into orbit, then made a swift return landing on an ocean platform, a live webcast showed.
It was the second successful landing at sea for entrepreneur Elon Musk's Space Exploration Technologies, or SpaceX, which intends to offer cut-rate launch services by re-using its rockets.
"Woohoo!!" Musk wrote on social media website Twitter after the landing. "May need to increase size of rocket storage hangar."
SpaceX successfully landed a rocket on a floating landing pad in April after four failed attempts. Another Falcon rocket had touched down on a ground-based landing pad at Cape Canaveral in December.
Before Friday's launch SpaceX had downplayed expectations for the rocket's successful return.
The rocket flying on Friday was traveling twice as fast as the one that landed last month so it could deliver a hefty television broadcast satellite into an orbit more than 20,000 miles (32,200 km) beyond that of the International Space Station, which is about 250 miles (400 km) above Earth.
The 23-story tall rocket lifted off from a seaside launch pad at Cape Canaveral Air Force Station at 1:21 a.m. EDT.
Perched atop the booster was the JCSAT-14 satellite, owned by the Tokyo-based telecommunications company, SKY Perfect JSAT Corp, a new customer for SpaceX.
About 2-1/2 minutes after launch the rocket's first stage shut down, separated, flipped around and headed toward a so-called drone ship stationed more than 400 miles (650 km) off Florida's east coast in the Atlantic Ocean.
The rocket's second stage continued flying to deliver the 10,300-pound (4,700-kg) JCSAT-14 satellite into orbit.
The satellite, built by Space Systems Loral in Palo Alto, California, a subsidiary of MacDonald Dettwiler and Associates is designed to provide television, data and mobile communications services to customers across Asia, Russia and Oceania and the Pacific Islands.
Friday's launch was the fourth of more than a dozen flights planned this year by SpaceX, which has a backlog of more than $10 billion worth of launch orders from customers including NASA.
Last week SpaceX won its first contract to launch a U.S. military satellite, breaking a 10-year-old monopoly held by United Launch Alliance, a partnership of Lockheed Martin Corp and Boeing Co.
(Editing by Clarence Fernandez, Greg Mahlich)