Space Exploration Technologies’ next-generation Falcon 9 rocket, which is being prepared for a debut test flight from the company’s new launch pad in California, is not quite ready for liftoff.

The Falcon rocket’s nine engines roared to life on Thursday for what is known as a “static test fire” (meaning the rocket stays bolted down), but all apparently was not perfect.

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“Full thrust achieved on 2 sec static fire,” company founder, chief executive and technical lead Elon Musk posted on Twitter early Friday. “Some anomalies to be investigated, so launch date tbd.”

Vandenberg Air Force Base in California — SpaceX’s landlord and range operator — had reserved Sunday for the Falcon 9 launch.

SpaceX has launched five previous Falcon 9 rockets from a refurbished launch pad at Cape Canaveral Air Force Station in Florida.

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The first launch of the upgraded Falcon 9 (which the company refers to as Falcon 9 v1.1) is primarily a demonstration, though the booster will be carrying a small science satellite, called Cassiope, owned by MDA Corp of Canada in collaboration with the Canadian Space Agency and Technology Partnerships Canada.

To entice a customer for a test flight, SpaceX offered the launch service at an 80 percent discount, Musk said.

 Image: Inside SpaceX mission control in Hawthorne, Calif., just before Thursday’s engine test. Credit: Elon Musk/SpaceX via Twitter.