BALTIMORE — NASA’s revolutionary James Webb Space Telescope is hurtling away from Earth and toward deep space on a long-awaited, high-risk mission that, if successful, will look deeper into the cosmic past than any telescope before.

The Webb blasted off Christmas morning from the European Space Agency’s spaceport in Kourou, French Guiana, on South America’s northeast coast, and early reports from NASA suggest the mission is going swimmingly.

This is, however, an unusually difficult mission involving an extraordinarily complicated instrument, and in the coming days and weeks the telescope will have to transform itself through hardware deployments, each of which is critical to the telescope’s ambitious astronomy.

Though relieved by the successful launch, NASA Deputy Administrator Pam Melroy acknowledged what everyone involved with the Webb knows: “We have some scary days ahead.”

That NASA chose to forge ahead with a Christmas launch was a sign of how seriously the agency and the global scientific community take this $10 billion mission, the long-delayed successor to the Hubble Space Telescope. Officials had challenging discussions about launching on a holiday, and amid the rapid spread of the omicron variant of the coronavirus, but decided to go on the first possible day. After two technical problems and one weather delay, that turned out to be Dec. 25.

Melroy put a positive spin on it: “It’s not bad that it’s happening on Christmas Day, which should be a day of hope and inspiration.”

The telescope left Earth in a folded position, fully enveloped in the cone of Arianespace’s heavy-lift Ariane 5 rocket, which rolled to the launchpad Thursday. Less than half an hour after launch, it separated from the final booster and was traveling at 22,000 miles per hour, “flying on its own in coast phase,” as NASA put it.

Early reports indicated that everything was “nominal” — precisely the space-jargon term that the thousands of people who have worked on the mission were hoping to hear on launch day.