SpaceX Examines Cracked Engine Nozzle on Private Rocket

falcon 9 rocket test
The private spaceflight company SpaceX test fires the nine engines of its second Falcon 9 rocket on Dec. 4, 2010 at Cape Canaveral Air Force Station in Florida ahead of a planned Dec. 7 launch to test the company's new Dragon space capsule. Credit: SpaceX (Image credit: SpaceX)

CAPE CANAVERAL, Fla. ? The private spaceflight company SpaceXis examining a cracked engine nozzle on its commercial Falcon 9 rocket that has?delayed the inaugural launch of the firm's new Dragon space capsule.

The company, formally known as Space ExplorationTechnologies, planned to launch the Falcon 9 rocket and its first operational Dragonspace capsule today (Dec. 7). But the company postponed the launch after discoveredtwo cracks in the aft end of the second-stage engine nozzle extension of theFalcon 9 rocket.

NASA and SpaceX officials have stated that a launch attemptcould occur as early as Wednesday. SpaceX is expected to announce a decisionthis evening.

The two cracks are located in a region near the end of thenozzle extension. Since the area experiences little stress, the fractures wouldlikely not have caused a flight failure on their own, SpaceX officials said. [INFOGRAPHIC:Inside Look at SpaceX's Dragon Capsule]

The bell-shaped nozzle extension, which measures 9 feet (2.7meters) tall and 8 feet (2.4 m) in base diameter, is made of an alloy metalwith a melting temperature high enough to boil steel. Yet, despite itsintricacies, this component is geometrically the simplest part of the engine,SpaceX officials said.

The Dragonspacecraft and Falcon 9 rocket form the core of SpaceX's plan to provideunmanned cargo deliveries to the International Space Station under a $1.6billion contract with NASA. SpaceX will provide 12 Dragon flights under thatcontract.

NASA plans to rely heavily on commercial spacecraft such as SpaceX'sDragon for access to low-Earth orbit once the agency retires its spaceshuttle fleet next year.

SpaceXfounder Elon Musk, a millionaire who also co-founded the Internet paymentservice PayPal, has said that while the initial Dragon capsules will serve asunmanned space freighters, SpaceX is also developing a crewed version of thespacecraft to carry up to seven people on round trip flights to orbit. ?

For the Dragon capsule's maiden flight, engineers andtechnicians are completing a thorough investigation to ensure that these cracksare not symptomatic of more serious problems.

SpaceX initially stated that a new launch attempt would notoccur earlier than Thursday, with additional opportunities on Friday andSaturday if needed.?

The company is considering several options, includingrepairing the crack or shipping a replacement part from their headquarters inHawthorne, Calif.

"The most likely path forward is that we will trim offthe thinnest portion of the nozzle extension, which is where the cracks arelocated, perform a thorough systems check and resume launch preparation,"SpaceX officials said in a statement.

SpaceX's Falcon 9 rocket set to launch this week is thesecond Falcon 9 booster to fly. The company successfully launched its firstFalcon 9 rocket in June.

You can follow Staff Writer Denise Chow onTwitter @denisechow.

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Denise Chow
NBC News science writer

Denise Chow is a former staff writer who then worked as assistant managing editor at Live Science before moving to NBC News as a science reporter, where she focuses on general science and climate change. She spent two years with, writing about rocket launches and covering NASA's final three space shuttle missions, before joining the Live Science team in 2013. A Canadian transplant, Denise has a bachelor's degree from the University of Toronto, and a master's degree in journalism from New York University. At NBC News, Denise covers general science and climate change.