Blue Origin is preparing for one of its biggest launches yet. On Sunday, the Jeff Bezos-owned commercial space company will attempt to send its 320-foot-tall New Glenn rocket into space for the first time.

The launch comes after almost a decade of development, and its outcome could threaten the dominance of Elon Musk’s SpaceX — not only in the commercial space industry but also in the satellite internet business. Here’s an overview of what you need to know about the New Glenn flight and how to watch it live.

First announced in 2016, Blue Origin’s New Glenn rocket is meant to shuttle cargo, satellites, and, in the future, people into space. The New Glenn is named after John Glenn, the first NASA astronaut to enter the Earth’s orbit.

Its first stage is powered by seven of Blue Origin’s powerful BE-4 engines, which run on liquified natural gas and liquid oxygen. Blue Origin aims to reuse New Glenn’s first stage for at least 25 missions, as it’s designed to touch down vertically on a sea-based platform following launch, allowing the company to retrieve it.

The rocket’s upper stage is disposable and carries Blue Origin’s payload. It’s capable of sending 13 metric tons to geostationary transfer orbit and 45 metric tons to low Earth orbit. Blue Origin says New Glenn is also “engineered with the safety and redundance required to fly humans.” Though Blue Origin initially aimed to launch New Glenn in 2020, its inaugural flight kept getting pushed back due to issues with the development of its BE-4 engine and other technical mishaps.

As pointed out by NPR, New Glenn has a similar carrying capacity to SpaceX’s Falcon Heavy rocket, but it stands out with a larger, 23-foot-wide cargo bay. If New Glenn’s launch is successful, it could heat up its rivalry with SpaceX as both companies vie to secure lucrative government contracts.

New Glenn is also key to Amazon’s Project Kuiper satellite internet initiative. Though the company’s first set of satellites is scheduled to launch aboard SpaceX’s Falcon 9 rocket this year, Blue Origin will eventually launch Project Kuiper satellites aboard New Glenn, rivaling SpaceX’s Starlink. Amazon plans to send 3,236 Project Kuiper satellites into space, which is still far fewer than Starlink’s growing constellation of more than 6,000 satellites.

New Glenn is set to take off from Cape Canaveral, Florida, with a three-hour launch window opening on January 12th at 1AM ET (10PM PT). The launch was originally scheduled for January 10th, but it was pushed back due to “a high sea state in the Atlantic.”

During this uncrewed launch, New Glenn will have the Blue Ring Pathfinder on board, a payload consisting of a communications array, a power system, and a flight computer. It will test the company’s Blue Ring spacecraft, which will help support missions with refueling, hosting, data relay, and cloud computing capabilities. The goal is for New Glenn to reach orbit, while “anything beyond that,” like landing its reusable booster is a “bonus,” according to Blue Origin CEO David Limp.

“This is our first flight and we’ve prepared rigorously for it,” Jarrett Jones, the senior vice president of New Glenn, said in a statement. “But no amount of ground testing or mission simulations are a replacement for flying this rocket. It’s time to fly. No matter what happens, we’ll learn, refine, and apply that knowledge to our next launch.”

Blue Origin will likely stream the launch live from its website and YouTube channel. We’ll embed the stream below once it becomes available.