NASA's Swift space telescope is set to fall back to Earth on Wednesday

Risk of harm to anyone on Earth

1 in 2,100 odds, per NASA

NASA expects re-entry at about 3:30 a.m. ET, give or take 11 hours, and most of the spacecraft to burn up, though some parts will likely survive.

Background

Launched in 2004 for a two-year mission, Swift studied gamma-ray bursts for nearly 22 years and examined more than 2,000 of them.

A rescue attempt in July, using a robotic satellite built by the company Katalyst, failed after the craft malfunctioned on its way to the telescope.