NASA has moved to replace the long-planned Exploration Upper Stage for its Space Launch System rocket with United Launch Alliance’s Vulcan Centaur 5 upper stage, a shift that could reshape the Artemis lunar program’s trajectory for years to come.

NASA is reportedly seeking rocket components from Boeing Co. and Lockheed Martin Corp's joint venture, the United Launch Alliance (ULA). Costs Ballooned In a report by Bloomberg on Wednesday, it was said that the Exploration Upper Stage of the agency's Space Launch System,

At the core of Isaacman’s concerns is the low flight rate of the SLS rocket and Artemis missions. During past exploration missions, from Mercury through Gemini, Apollo, and the Space Shuttle program, NASA has launched humans on average about once every three months. It has been nearly 3.5 years since Artemis I launched.

NASA made major changes to its Artemis lunar architecture, adding a test flight of lunar landers in Earth orbit while canceling planned upgrades to the SLS.

NASA is shaking up its Artemis mission to the moon, canceling a multibillion-dollar Boeing Co. upgrade to the centerpiece SLS rocket and adding another test flight to a program beset by delays and cost overruns.

NASA on Friday announced an abrupt change to its pathway to getting astronauts back on the lunar surface, opting to add in an additional crewed test flight before attempting to land.