* 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) - Anunmanned Falcon 9 rocket blasted off from California on Sundayto test upgrades needed for planned commercial launch services.
The 22-story rocket, built and flown by Space ExplorationTechnologies, or SpaceX, soared off a newly refurbished, leasedlaunch pad at Vandenberg Air Force Station at noon EDT/1600 GMT.
The Falcon 9 blazed through clear blue skies out over thePacific Ocean, aiming toward an orbit that flies over Earth'spoles. Perched on top of the rocket was a small science andcommunications satellite called Cassiope, built by MDA Corp ofCanada.
The upgraded Falcon 9 v1.1 has engines that are 60 percentmore powerful than previous versions, longer fuel tanks, newavionics, new software and other features intended to boost liftcapacity and simplify operations for commercial service.
Privately owned SpaceX has contracts for more than 50launches of its new Falcon 9 and planned Falcon Heavy rockets.
Ten of those missions are to fly cargo to the InternationalSpace 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 Forcesatellites but is looking to break the monopoly United LaunchAlliance, a partnership of Lockheed Martin and Boeing, has on flying big military satellites as well.
SpaceX already has flown three Dragon capsules to thestation and made two other successful test flights with itsolder version Falcons.
The company advertises Falcon 9 launch services for $56.5million. Company founder and chief executive Elon Musk said hewould like to discount that price by recycling and reusing theFalcon's first stage. Currently, the spent boosters splash downinto the ocean and cannot be reused.
Toward that goal, SpaceX has been working on related programcalled Grasshopper to fly a booster back to its launch site.Engineers have not yet tested how the system would work overwater but they may get a trial run during Sunday's Falcon 9flight.