"Three, two, one, ignition and liftoff", said a SpaceX commentator as the Falcon 9 rocket launched under cover of darkness from Cape Canaveral, Florida, at 8:00 pm (0100 GMT Monday).
It will be carrying a secret payload for the US government, code-named Zuma.
SpaceX has launched a secret satellite codenamed Zuma on its first flight of the new year. The company has said it plans to launch roughly 30 missions in 2018 after completing a record 18 past year.
The launch was originally scheduled to take place in November, but was scrubbed due to a rocket fairing issue.
Now pro-government marchers have their say in Iranian cities
On Sunday police used water cannon to disperse protesters at a major intersection, as captured in a video obtained by BBC Persian. Undoubtedly high on his list is the USA , where President Donald Trump has tweeted his support for the protests for several days.
ESPN's Nolan hosts after blasting Trump
And the Emmy-winning Nolan, who joined ESPN from rival Fox Sports three months ago, was clearly having fun. The first insult she used for him is bleeped out, but then she added that he is a "fucking stupid person".
Khloe Kardashian Plans to Give Birth in Cleveland
Khloe Kardashian revealed on Thursday that she's looking to name her baby (if it's a boy), after her boyfriend Tristan Thompson . Still, it looks like Kris is at the top of the list of family members Khloe wants to have by her side.
But the launch was delayed. SpaceX is edging ever closer to the first launch of Falcon Heavy, and the last thing it needed was a problem with a (mostly) routine mission. The reusable rocket landed about seven minutes after liftoff, SpaceX said.
SpaceX's first mission of 2018 has more than its share of mystery. The launch had been pushed back several times since late 2017, with the past week's "extreme weather" on the East Coast contributing to the most recent delay.
While it isn't exactly clear what the Zuma mission is or precisely who it's for, we do have some clues.
SpaceX launched Zuma from its SLC-40 launch facility at Cape Canaveral in Florida, which was used instead of its other launch facility at Cape Canaveral because that was being employed for preparations for the launch of SpaceX's Falcon Heavy rocket. The company has successfully launched "Zuma", a mysterious government payload, into orbit from Cape Canaveral.