Two rocket launches with satellites by Space X and United Launch Alliance are scheduled for Thursday morning from Cape Canaveral Space Force Station in Central Florida.

United Launch Alliance prepares its Atlas rocket to launch a payload of Kuiper satellites for Amazon on Thursday from Launch Complex 41 at the Cape Canaveral Space Force Station. Photo by Joe Marino/UPI UPI United Launch Alliance's Atlas rocket on Wednesday is on Launch Complex 41 at the Cape Canaveral Space Force Station. Photo by Joe Marino/UPI UPI United Launch Alliance is planning to launch another batch of satellites for Amazon aboard an Atlas rocket. Photo by Joe Marino/UPI UPI The SpaceX Falcon 9 rocket launches 28 Starlink satellites at 6:53 a.m. Sunday from Launch Complex 40 at the Cape Canaveral Space Force Station. Photo by Joe Marino/UPI UPI

Sept. 24 (UPI) -- Two rocket launches with satellites by Space X and United Launch Alliance are scheduled for Thursday morning from Cape Canaveral Space Force Station in Central Florida.

SpaceX is scheduled to lift off at 4:36 EDT with a Falcon 9 rocket taking 28 Starlink satellites into low-Earth orbit from Launch Complex 40. There is a four-hour launch window. This is the 22nd flight scheduled for the first-stage booster, which is scheduled to land on the droneship A ShortFall of Gravitas in the Atlantic Ocean, SpaceX said.

At 8:09 a.m., a United Launch Alliance Atlas V rocket is scheduled to lift from Launch Complex 41 with 27 satellites to be deployed in a low-Earth orbit. The launch window is 29 minutes, ULA said. Its satellites are for the Amazon Kuiper constellation project "to provide fast, reliable internet to customers around the world, including those in unserved and underserved communities," the company said.

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There is a 90% chance of "go for launch" for the two launches, according to the Space Force's 45th Weather Squadron.

Because of the Atlas V's 205-foot height, visibility from most of Florida and other adjacent states is possible, depending on weather.

ULA has launched two other satellite payloads for Amazon: April 28 and June 23.

The two private companies have drastically different satellites above Earth.

Starlink has 8,460 functioning satellites, according to Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics.

Project Kuiper will have 129 satellites after Thursday's deployment, though there are plans for 3,200 using eight Atlas V and 38 Vulcan rockets. ULA is joint venture with Lockheed Martin and Boeing formed in 2006.

SpaceX is also planning to launch 24 Starlink satellites from Vandenberg Space Force Base in California at 6:47 p.m. PDT Thursday

On Wednesday morning, SpaceX launched a trio of spacecraft each meant to study the sun and space weather, and their effects on Earth. The Falcon 9 rocket launched from NASA's Kennedy Space Center in Florida around 7:30 a.m. EDT.