The launching of a privately owned cargo rocket heading to the International Space Station was aborted at the last second on Saturday morning.

The rocket’s nine engines had ignited, but computers detected a discrepancy and shut them down. The next launching attempt will be, at the earliest, on Tuesday at 3:44 a.m., NASA officials said.

The rocket and its cargo capsule, both built by the Space Exploration Technologies Corporation of Hawthorne, Calif., represent an important step in NASA’s evolution to rely more heavily on commercial companies for its human spaceflight program.

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