Enlarge / Artist’s illustration of the OSAM-1 spacecraft (bottom) linking up with the Landsat 7 satellite (top) in orbit. (credit: NASA)

NASA has canceled an over-budget, behind-schedule mission to demonstrate robotic satellite servicing technology in orbit, pulling the plug on a project that has cost $1.5 billion and probably would have cost nearly $1 billion more to get to the launch pad.

The On-orbit Servicing, Assembly, and Manufacturing 1 mission, known as OSAM-1, would have grappled an aging Landsat satellite in orbit and attempted to refuel it, while also demonstrating how a robotic arm could construct an antenna in space. The spacecraft for the OSAM-1 mission is partially built, but NASA announced Friday that officials decided to cancel the project “following an in-depth, independent project review.”

The space agency cited “continued technical, cost, and schedule challenges” for the decision to cancel OSAM-1.