Another internet-satellite megaconstellation is starting to take shape.

A Soyuz rocket carrying 34 of OneWeb's broadband satellites lifted off today (Feb. 6) from Baikonur Cosmodrome in Kazakhstan, rising off the pad at 4:42 p.m. EST (2142 GMT; 2:42 a.m. on Feb. 7 local time).

The Soyuz — which is operated by French company Arianespace — deployed all 34 spacecraft as planned by 3 hours and 45 minutes after launch, at an altitude of 280 miles (450 kilometers). The 325-lb. (147 kilograms) satellites will then make their own way to their operational orbit, which lies about 745 miles (1,200 km) above Earth.

Related: In photos: OneWeb launches new global satellite internet constellation

We're excited to share that the launch of 34 satellites today was a success! We are on schedule to provide global coverage to customers in 2021, starting with the first commercial services in the Arctic this year. https://t.co/iDEfRPQadi #OneWebLaunchFebruary 7, 2020

Today's launch was the second for OneWeb but the first to loft such a big batch for the company. The previous OneWeb mission, also flown by a Soyuz, put six satellites up in February 2019 .

But the launch cadence will ramp up significantly, and soon: Arianespace's deal with OneWeb calls for 19 additional liftoffs through the end of 2021. These missions will flesh out OneWeb's initial constellation of 650 satellites, which "will provide high-speed, low latency services to a wide range of customers in sectors that include aeronautics, maritime, backhaul services, community Wi-Fi, emergency response services and more," OneWeb and Arianespace representatives wrote in an explanation of today's mission .

"Central to its mission, OneWeb also will focus on connecting schools and bridging the digital divide for people everywhere," they added.

OneWeb, which has headquarters in London and Virginia, plans to provide internet service on a test basis sometime this year and be up and running with global, 24-hour service in 2021.

OneWeb has serious competition in the internet-satellite space. For example, SpaceX has already launched 240 satellites for its huge Starlink constellation , which could eventually consist of tens of thousands of spacecraft. Elon Musk's company has approval from the U.S. Federal Communications Commission to loft 12,000 Starlink satellites, and SpaceX has filed the paperwork with an international regulator to launch up to 30,000 more.

And Amazon is developing its own network called Project Kuiper, which is envisioned to incorporate more than 3,000 satellites. None of the Kuiper craft have left the ground, however.

These megaconstellations will change the night sky significantly if they take shape as planned. Earth orbit currently hosts just 2,000 or so operational satellites, and humanity has launched only 9,150 objects to space in all of history, according to the United Nations Office for Outer Space Affairs .

Indeed, scientists have already voiced concerns about Starlink's potential to disrupt astronomical observations. And experts have stressed that spacecraft builders and operators must now start taking stronger measures to ensure that Earth orbit doesn't get too cluttered with space junk.

As more and more spacecraft go up, after all, the chances of a collision get higher and higher (especially if proactive mitigation measures aren't taken). Even a single smashup can generate thousands of pieces of new debris, as we've seen several times during the past decade or so.

Broadband megaconstellations aren't the only drivers of the space-junk worries. The drop in the cost of building and launching satellites means that many more craft of various types are going up, and they're being operated by people with different levels of experience and expertise.

Editor's note: This story was updated at 1:25 a.m. EST on Feb. 7 with news of successful satellite deployment.

Mike Wall's book about the search for alien life, " Out There " (Grand Central Publishing, 2018; illustrated by Karl Tate ), is out now. Follow him on Twitter @michaeldwall . Follow us on Twitter @Spacedotcom or Facebook .