NASA's long-awaited moonshot with astronauts is off until at least March because of hydrogen fuel leaks that marred the dress rehearsal of its giant new rocket. It's the same problem that delayed the Space Launch System rocket's debut three years ago.

As NASA prepares to send astronauts around the moon, a critical dress rehearsal on Monday will reveal whether its rocket is truly ready to fly.

After a major winter storm swept across the country in late January, a prolonged surge of Arctic air tightened its grip on large areas of the U.S. pushing temperatures well below normal. From the Midwest to the South, the impacts of snow and ice became more extreme.

NASA began a two-day practice countdown Saturday leading up to the fueling of its new moon rocket, a crucial test that will determine when four astronauts blast off on a lunar flyby. Already in quarantine to avoid germs,

New simulations performed on a NASA supercomputer are providing scientists with the most comprehensive look yet into the maelstrom of interacting magnetic structures around city-sized neutron stars in the moments before they crash.