"At 1:21 before launch [scheduled for 11:18 GMT], a thrust vector control actuator for the Falcon 9's 2nd stage failed to perform as expected," the agency said.
NASA added that the spacecraft's launch has been rescheduled for 10:09 GMT Friday, January 9. The spacecraft was to deliver 1.6 metric tons of cargo, including provisions, equipment for scientific experiments and clothing for the crew.
Launch is scrubbed for today and we are now targeting launch on Jan. 9th at 5:09am ET. http://t.co/hniEJZVl4k
— SpaceX (@SpaceX) January 6, 2015
The Dragon's launch has been postponed twice before, including due to a glitch in the booster rocket prior to the spacecraft's liftoff earlier in December. However, its developer SpaceX made assurances on Monday that the launch was rescheduled as a precaution and everything was ready for Tuesday's takeoff.
SpaceX, a private developer under contract with NASA, describes its two-stage Falcon 9 rocket as highly reliable. According to the company's website, the rocket's nine Merlin engines allow it to "sustain up to two engine shutdowns during flight" and still carry on its mission. The cargo vehicle's first launch on a Falcon 9 booster took place in 2012.
SpaceX became the first commercial company to deliver supplies to the ISS. Last September, it was awarded a $6.8 billion contract with Boeing to develop manned flights to the ISS. The use of Falcon 9 rockets is expected in SpaceX's manned missions.
