What winds up on the shelf is the result of constant evaluation, competing priorities and calculated decisions.

NASA’s first crewed mission around the moon since the Apollo era is underway. Follow the latest on the astronauts, milestones and mission path and the trip back to Earth.

With gas prices crossing $4 a gallon, the EPA says cheaper, more ethanol-rich fuel will ease the pain. The math doesn't ...

Four astronauts have embarked on a high-stakes flight around the moon. It's humanity’s first lunar voyage in more than half a ...