A NASA spacecraft with samples from an asteroid is making its long return back to Earth.

After nearly five years in space, the OSIRIS-REx spacecraft has begun its 1.4 billion-mile trek back home, which will take about 2.5 years.

The spacecraft reached an asteroid in 2018 and spent two years flying near and around it before collecting rubble from the surface late last year.

The asteroid it collected from is estimated to be 4.5 billion years old.

It will be the biggest sample size for the U.S. since the Apollo moon rocks.

This story was originally published by Robin Dich and Alex Livingston at Newsy.