Update May 23rd, 11:35PM ET: SpaceX successfully deployed all 60 Starlink satellites into orbit following liftoff, and the individual vehicles will fan out in orbit over time. The company also landed its Falcon 9 rocket following launch, marking this particular rocket’s third time going to space and back.

Update May 23rd, 12:57AM ET: All 60 Starlink satellites are now online. The solar array deployment should be happening soon.

Original Story: Tonight, SpaceX will attempt to jumpstart its ambitious internet-from-space initiative known as Starlink, by launching the first 60 production satellites of nearly 12,000 planned spacecraft into a low orbit above Earth. These inaugural probes do not have all of the capabilities that the finalized satellites are supposed to have, but their launch will get the ball rolling on Starlink — and should help SpaceX learn what it takes to operate a large crop of vehicles in space.

“This was one of the hardest engineer projects I’ve ever seen done, and it’s been executed really well,” SpaceX CEO Elon Musk said during a conference call.

Starlink is one of SpaceX’s most formidable projects. SpaceX envisions putting up two groups of satellites into orbit: one batch of 4,409 satellites that will operate between 340 miles (550 kilometers) and 823 miles (1,325 kilometers) up. And then there’s a second batch of 7,518 satellites that would fly slightly lower, between 208 miles (335 kilometers) and 214 miles (346 kilometers) in altitude. That’s a total of 11,927 satellites all zooming over the Earth, providing internet connectivity to up to a million user terminals on the surface.

“This was one of the hardest engineer projects I’ve ever seen done.”

Ultimately, the goal is to provide global internet coverage from space, with very short lag times in signal — something that current internet-beaming satellites can’t accomplish. Most satellites that provide internet coverage from space are in much higher orbits known as geostationary orbit — a path about 22,000 miles above the equator. The problem with these satellites, though, is that it takes a long time to get their data, as signals have to travel thousands of miles through space and back. That’s why SpaceX and other aerospace companies are proposing constellations in much lower orbits, to cut down on this latency issue.

When you move to lower orbits, you need a lot more satellites to provide complete coverage of the Earth, which is why SpaceX and others are proposing new constellations numbering in the hundreds and thousands. Right now, there are nearly 2,000 functioning satellites in orbit, but satellite internet initiatives like those of SpaceX, OneWeb, and more could quadruple that number. It’s led many aerospace experts to wonder how this might clog up the space around Earth, and raised concerns about the risks of in-flight collisions and space debris. To lower the possibility of creating debris, SpaceX has proposed moving some of its satellites to lower orbits, and it also plans to dispose of these satellites over water, where they’ll burn up almost completely in the atmosphere and not pose a threat to people or property below.

However, Musk argues that the chances of collisions happening in space will be small. “The space junk thing — we don’t want to trivialize it or not take it seriously, because we certainly do take it seriously — but it’s not crowded up there,” says Musk. “It’s extremely sparse.”

If the debris risks are addressed, the benefits of these constellations could be immense especially in rural and remote areas. “This would provide connectivity to people that either don’t have any connectivity today, or where it’s extremely expensive and unreliable,” Musk says. He also said that this system would “provide a competitive option” to people in more developed areas who might want another option for their internet provider.

The Federal Communications Commission has already granted SpaceX permission to launch the entirety of its nearly 12,000-satellite constellation. SpaceX launched its first two test satellites, TinTin A and TinTin B, in February of 2018, and the company now has about six years to launch half of the full constellation to bring its license with the FCC into full use.

“This would provide connectivity to people that either don’t have any connectivity today, or where it’s extremely expensive and unreliable.”

Tonight’s launch will get SpaceX started on meeting its deadline, though the satellites going up on this mission don’t boast all of the capabilities of the finalized probes. They have radio antennas to communicate with Earth, thrusters that can propel them through space, as well as star trackers that will help the orient and navigate. SpaceX claims the satellites can even autonomously track other debris in orbit using the Air Force’s tracking data and avoid running into objects. But these first satellites don’t have a way to communicate with one another, which is going to be necessary in the future. Since the satellites will be zooming over the Earth, they’ll need to trade off coverage whenever they move to a new patch of the surface, and that will require satellite-to-satellite communication.

However, Musk did say that these first satellites can get around this issue by bouncing signals off of gateways on the ground that can then bounce signals to another satellite. “That way we can get connectivity without using intersatellite links,” Musk says. “The system can still have global connectivity,” except for maybe some spots where you would need a gateway to bounce back signals over the ocean. Musk says this solution will only needed for the first few batches of production satellites. “It is version one,” says Musk. “As we get to version two and three, we do expect to add laser inner satellite links.”

First 60 @SpaceX Starlink satellites loaded into Falcon fairing. Tight fit. pic.twitter.com/gZq8gHg9uK — Elon Musk (@elonmusk) May 12, 2019

Over the weekend, SpaceX CEO Elon Musk showed off a picture of all 60 satellites stacked on top of one another inside the Falcon 9 rocket’s nosecone that will take them to orbit. It’s a tight fit inside the vehicle, and each satellite weighs about 500 pounds (227 kilograms) each, making this the heaviest payloads SpaceX has ever carried to space, weighing in at 18.5 tons.

SpaceX plans to keep launching batches of 60 in the years to come, with the goal of launching between 1,000 to 2,000 satellites a year, according to Musk. Musk says the company can get to full coverage after about 24 launches or so, but will continue to add satellites as more customers opt into the system. “One does not need anywhere near 10,000 satellites to be effective,” he says.

“One does not need anywhere near 10,000 satellites to be effective.”

The plan also revolves around SpaceX rolling out ground stations and user terminals that receive the signals from the satellites. Musk described the individual user terminals as pizza-shaped antennas that points up at the sky and finds the nearest satellite to connect to. “You won’t even notice the fact that it’s switching between satellites,” says Musk. “There’s a lot of advanced technology in here, all the way down to the chip level.”

And if all goes well, Musk envisions SpaceX getting a big slice of money, that could be used to fund the company’s longer term projects, like the development of a new giant rocket called Starship. “Total internet connectivity revenue in the world is on the order of a trillion dollars, and we think maybe we can access about 3 percent of that, or maybe 5 percent,” he says.

But first, SpaceX has to get started. The Falcon 9 that will take tonight’s 60 satellites to orbit is one that SpaceX has used a few times before. It flew the Telstar 18 VANTAGE satellite back in September of 2018, and then flew for a second time in January of this year, taking a group of satellites in orbit for Iridium. Now it’ll be flying tonight from Cape Canaveral Air Force Station in Florida, and after takeoff, it’ll attempt to land on one of SpaceX’s drone ships in the Atlantic Ocean. That means this vehicle could potentially fly for a fourth time if it sticks the touchdown.

This launch was originally supposed to take place last week, but was delayed once because of high winds above the launch site. SpaceX then postponed to this week in order to check the software on the satellites. Now, takeoff is scheduled for 10:30PM ET, and SpaceX has a launch window that lasts for another hour and a half, so the company can take off until 12:00AM ET. About an hour after takeoff, SpaceX will deploy the satellites in orbit by rotating the rocket and using the satellites’ inertia to spread them out into orbit. SpaceX plans to show the whole mission from start to finish, with live coverage starting about 15 minutes before launch. Check back then to watch what should be an interesting satellite deployment.

Update May 16th, 8:30PM ET: After delaying the launch on Wednesday, May 15th, due to high winds, SpaceX delayed the launch again on Thursday, May 16th in order to update software on the satellites. “Always want to do everything we can on the ground to maximize mission success,” the company tweeted.