A U.S. 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 Orbital ATK capsule arrives at the space station Wednesday as planned, it will represent the first U.S. 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 unmanned Atlas to blast off in late afternoon with 7,400 pounds of space station cargo, not to mention some Christmas presents for the awaiting crew.

Tony Bruno, president of rocket maker United Launch Alliance urged, "Everyone cross your fingers and think happy weather thoughts."

It apparently worked.

The rocket sored safely through clouds, as the space station sped over the Atlantic, north Bermuda.

Launch controllers applauded, shook hands and hugged one another once the Cygnus cargo carrier reached the proper orbit 21 minutes after liftoff.

"This is about as good as it gets," said Vernon Thorp, a United Launch Alliance manager.

The space station astronauts got to see some of the rocket contrails.

"Caught something good on the horizon," Space Station Commander Scott Kelly reported via Twitter.

The six station astronauts — two of them deep into a one-year mission — have gone without American shipments since April. Two private companies contracted for more than $3.5 billion by NASA to replenish the 250-mile-high lab are stuck on Earth with grounded rockets. Orbital ATK bought another company's rocket, the veteran Atlas V, for this supply mission.

Orbital's previous grocery run, its fourth, ended in a fiery explosion seconds after liftoff in October 2014. SpaceX, the other supplier, suffered a launch failure in June on its eighth trip.

Russia also lost a supply ship earlier this year. But it's since picked up the slack, with another resupply mission scheduled just before Christmas, and Japan has chipped in as well.

Much-needed food is inside Orbital's cargo carrier, named Cygnus after the swan constellation. NASA normally likes to have a six-month stash of food aboard the space station, but it's down a couple months because of the three failed flights. Space station program manager Kirk Shireman expects it will take another year to get the pantry full again — provided there are no more accidents.

Also aboard the newest Cygnus capsule: clothes, toiletries, spacewalking gear, air-supply tanks and science experiments.

This is the first time that the United Launch Alliance's Atlas V has served the space station. Normally used for hefty satellite launches, it is the mighty successor to the Atlas used to put John Glenn into orbit in 1962. Boeing intends to use the Atlas V to boost the Starliner capsules it's building to ferry astronauts to the space station beginning in 2017.

Orbital plans to use another Atlas rocket for a supply run in March, then return its own Antares rocket to flight from Virginia in May.

SpaceX — also part of NASA's commercial crew effort — aims to restart station deliveries in January with its Falcon rockets.

While acknowledging 2015 has been a difficult year because of the disrupted supply chain, Shireman said commercial space is inevitable and will drive down launch costs. NASA's 30-year shuttle program proved expensive and complicated, and, on two flights, deadly.

"It is our future," Shireman stressed at a news conference last week.

The Cygnus launched Sunday is named after Mercury 7 astronaut Deke Slayton, a pioneer in commercial spaceflight before his death in 1993.