Ding-dong! The Exploration Upper Stage is dead

In his 1961 novel The Winter of Our Discontent, John Steinbeck wrote of loss, "It's so much darker when a light goes out than it would have been if it had never shone.

Contracted to Boeing more than a decade ago, the Exploration Upper Stage upgrade was intended to allow the SLS rocket to launch not just the Orion spacecraft to the Moon, but large payloads alongside it. That the development of capable rockets by SpaceX, Blue Origin, and United Launch Alliance to deliver large cargo to the Moon rendered it obsolete mattered, for a long time, not at all.

The rocket's death came via a seemingly pedestrian notice posted on a government procurement website: "NASA/MSFC intends to issue a sole source contract to acquire next-generation upper stages for use in Space Launch System (SLS) Artemis IV and Artemis V from United Launch Alliance (ULA).