'No one thought it was going to be possible.' A space telescope is falling out of space. This is NASA's daring plan to save it. (video)

A split image of NASA's Swift observatory in orbit and the Katalyst spacecraft that will save it from falling out of space.

WALLOPS ISLAND, Va. — For over 20 years, NASA's Swift space observatory has been conducting prolific science in orbit, hunting for signs of gamma-ray bursts — the most powerful explosions in the universe. Now, it's falling to Earth, doomed to a fiery death by the end of the year as its orbit decays.