What is EUS? The EUS-enabled Space Launch System (SLS) rocket is the foundational capability for future deep space missions.
Starting with Artemis IV, the Exploration Upper Stage (EUS) will replace the Interim Cryogenic Propulsion Stage (ICPS) on NASA’s SLS rocket as it evolves to its Block 1B configuration, allowing NASA to send both astronauts and large payloads to the deep space destinations in a single mission. It’s expected to carry 40% more payload than the initial Block I configuration that features ICPS as the upper stage.
What makes EUS different? EUS implements innovative capabilities to enable NASA’s Moon to Mars objectives.
“EUS is designed from the ground up for its mission,” said James Savage, Boeing’s EUS chief engineer. “We are designing EUS for missions that require more capability and payload, which leads us to prioritize safety and functionality in the development and build process.”
One example of a new functionality leveraged by EUS is its “uplink” capability. While EUS can complete mission tasks autonomously, the upper stage can also be commanded by the ground crews or the human capsule via the uplink capability.
“For instance, when EUS is functioning in proximity operations – or in other words when the spacecraft has separated from EUS but is still within proximity – the crew in the spacecraft can command EUS to perform certain actions to help them with the task at hand, like extracting payloads from EUS,” Savage explained.