The spacecraft had been released from the orbiting lab on Friday at 6:40 am (local time), and then stayed in independent orbit for two days, before firing its engines and pushing into Earth's atmosphere.
The de-orbit burn had been scheduled to take just under 30 minutes.
The crew on board the space station watched and documented the spacecraft's plasma trail, posting pictures of the comet-like streak to Twitter.
Cygnus launched July 13 and arrived at the ISS three days later, bearing a load of 1,657 kilograms of gear, food and science experiments.