Amazon plans to launch two test satellites for its Kuiper broadband network late next month, on a United Launch Alliance Atlas V rocket.

The company had originally planned to be on the inaugural flight of ULA's new Vulcan rocket, but the vehicle has been delayed.

Amazon delivered the satellites to the Vulcan test site back in March, and they have since been in storage. Vulcan was first set to fly in early 2023, before being delayed to this summer. It has now been pushed back again to the fourth quarter, following a giant hydrogen explosion during testing of the rocket's upper stage and other issues.

While that initial launch was set to see Amazon share the rocket with NASA and Astrobotic, it will now solely use the Atlas V rocket - with a target date of September 26. Amazon has a 2026 regulatory deadline to launch the 3,200 satellites that will make up the Internet constellation. It eventually hopes to field more than 7,700 satellites.

Last year, Amazon signed a deal with three rocket providers for 83 launches in the sector's largest-ever procurement deal. It has pledged more than $10 billion to the effort, but remains behind rival SpaceX.

The Elon Musk company already operates a fleet of more than 4,000 satellites and claims to have more than 1.5 million active subscribers. However, governments have become increasingly concerned about Musk's public comments and business entanglements.