Amazon's Project Kuiper launches 27 satellites on cryogenic-powered Atlas V

In the final hours ahead of launch, around 66,000 gallons of liquid oxygen and liquid hydrogen were loaded into the Atlas V rocket and its Centaur upper stage at Cape Canaveral Space Force Station in Florida, US.

The fuelling operation was carried out over a tightly controlled 90-minute window, with propulsion console operators commanding pad systems from ULA's Launch Control Center.

ULA is a US launch provider formed as a joint venture between Lockheed Martin Space and Boeing Defense, Space & Security.

The company confirmed on its official X account that the Atlas V flight carried "another batch of 27 satellites" for the Amazon LEO 4 mission, continuing the phased deployment of Amazon's Kuiper constellation.

Amazon's Project Kuiper is a low Earth orbit satellite programme designed to provide global broadband connectivity.

The initiative aims to deploy a constellation of more than 3,000 satellites to deliver high-speed, low-latency internet access, particularly to underserved and remote regions.

Cryogenic propellants are crucial. The rocket's first stage uses liquid oxygen and RP-1 kerosene, while the Centaur upper stage is powered by liquid hydrogen and liquid oxygen.

Liquid hydrogen must be stored and transferred at around -253°C, placing stringent requirements on insulation, transfer systems, and timing to manage boil-off ahead of launch.

The use of cryogenic fuels allows for high propulsion efficiency and accurate orbital placement, while also highlighting the need for dependable cryogenic gas supply and launch-site infrastructure.

Space launch remains one of the most demanding end-uses for liquid oxygen and liquid hydrogen, with strict requirements around purity, delivery reliability, and handling.

Beyond launch, cryogenic gases are also increasingly being explored for in-space operations.

Companies such as Eta Space are developing cryogenic storage, transfer, and ground-support technologies aimed at enabling orbital refuelling and long-duration missions.

Our website spoke with Eta Space CEO William Notardonato earlier this year. Read more here.