* Older version had five successful flights
* Company has backlog of more than 50 missions
* Launches for NASA, commercial, military pending
By Irene Klotz
VANDENBERG AIR FORCE BASE, Calif., Sept 29 (Reuters) - An unmanned Falcon 9 rocket blasted off from California on Sunday to test upgrades needed for planned commercial launch services.
The 22-story rocket, built and flown by Space Exploration Technologies, or SpaceX, soared off a newly refurbished, leased launch pad at Vandenberg Air Force Station at noon EDT/1600 GMT.
The Falcon 9 blazed through clear blue skies out over the Pacific Ocean, aiming toward an orbit that flies over Earth's poles. Perched on top of the rocket was a small science and communications satellite called Cassiope, built by MDA Corp of Canada.
The upgraded Falcon 9 v1.1 has engines that are 60 percent more powerful than previous versions, longer fuel tanks, new avionics, new software and other features intended to boost lift capacity and simplify operations for commercial service.
Privately owned SpaceX has contracts for more than 50 launches of its new Falcon 9 and planned Falcon Heavy rockets.
Ten of those missions are to fly cargo to the International Space Station for NASA. The other customers are non-U.S. government agencies and commercial satellite operators.
SpaceX also has two contracts for small U.S. Air Force satellites but is looking to break the monopoly United Launch Alliance, a partnership of Lockheed Martin and Boeing , has on flying big military satellites as well.
SpaceX already has flown three Dragon capsules to the station and made two other successful test flights with its older version Falcons.
The company advertises Falcon 9 launch services for $56.5 million. Company founder and chief executive Elon Musk said he would like to discount that price by recycling and reusing the Falcon's first stage. Currently, the spent boosters splash down into the ocean and cannot be reused.
Toward that goal, SpaceX has been working on related program called Grasshopper to fly a booster back to its launch site. Engineers have not yet tested how the system would work over water but they may get a trial run during Sunday's Falcon 9 flight.