CAPE CANAVERAL, Fla. — A shipment of much-needed groceries and other astronaut supplies rocketed toward the International Space Station for the first time in months Sunday, reigniting NASA’s commercial delivery service.

If the capsule, operated by Orbital ATK, an aerospace and defense company, arrives at the space station on Wednesday as planned, it will be the first American delivery since spring.

To NASA’s relief, the weather cooperated after three days of high wind and cloudy skies that kept the Atlas V rocket firmly on the ground. Everything came together on the fourth launch attempt, allowing the crewless Atlas to blast off late in the afternoon with 7,400 pounds of space station cargo, along with Christmas presents for the awaiting crew.

Tony Bruno, president of United Launch Alliance, which made the rocket, urged, “Everyone cross your fingers and think happy weather thoughts.”