OneWeb plans to launch 34 communications satellites from Kazakhstan at 1:06 p.m. EDT Saturday -- its third such launch of satellites made in Florida.
The communications company based in London and Virginia has been mass-producing satellites near Kennedy Space Center since last year. The company previously launched 40 satellites from space centers in Kazakhstan and South America.
Saturday's launch is planned for Russia's Baikonur Cosmodrome in Kazakhstan, using Soyuz rockets purchased through the French space firm Arianespace. OneWeb said the weather for the launch time is expected to be favorable.
"Rocket is now on the launch pad and we are continuing to prep for our third #OneWebLaunch," the company said on Twitter.
OneWeb is one of several U.S. companies competing to launch huge new constellations of satellites to provide high-speed reliable Internet around the globe. Others include SpaceX's Starlink, Amazon and Telesat.
SpaceX has the largest constellation so far, at 362 satellites, and plans for up to 42,000.
But SpaceX and OneWeb appear to be aiming at different markets, said Shagun Sachdeva, a satellite analyst with Northern Sky Research.
"SpaceX officials have indicated Starlink will be a premium product, that they aren't going super cheap," Sachdeva said. "With OneWeb, they are going more for rural areas, underserved parts of the planet, and cheaply."
OneWeb is a relatively new company that announced its plans to build in Florida in 2016. OneWeb Satellites, a subsidiary and a joint venture with European aerospace company Airbus, opened a factory in 2019.
Initially, OneWeb founder Greg Wyler said he would launch with Virgin Galactic, and then signed a deal with Jeff Bezos' Blue Origin rocket company. But neither of those companies has launched a payload into space.
OneWeb said it is dedicating Saturday's launch to the late Russian cosmonaut Alexei Leonov, who became the first person to walk in space in 1965.
The satellites will be headed to a near-polar orbit about 280 miles high, after which they will be raised to their final orbit of approximately 745 miles. OneWeb Satellites are about the size of a small refrigerator.
By comparison, Starlink satellites orbit at a height of about 340 miles above the Earth, and feature a flat-panel design about the size of a large dinner table. Both companies' satellites have solar panels that extend after deployment.
The Kármán line that defines space is 62 miles high, and the International Space Station is orbiting Earth at more than 250 miles high.