SpaceX Dragon cargo capsule boosts ISS higher above Earth in key test

A Dragon just pushed the International Space Station a little farther away from Earth.

SpaceX’s Dragon cargo spacecraft successfully finished a test reboost of the International Space Station (ISS) on Wednesday (Sept. 3), according to NASA. The freighter fired two of its Draco engines for 5 minutes and 3 seconds during the maneuver, agency officials wrote in a Wednesday statement.

The ISS orbits roughly 250 miles (400 kilometers) above Earth on average but naturally falls back to our planet due to atmospheric drag. (There isn't much atmosphere up that high, but the few stray molecules make a difference over time.) Visiting cargo spacecraft therefore take on the job of lifting the orbiting complex higher every few months.

This job has historically been done primarily by Russian Progress spacecraft, but Russia may withdraw from the ISS program as soon as 2028. (The ISS is expected to keep operating until late 2030 or early 2031.)

NASA has therefore been asking the current U.S. ISS resupply craft — SpaceX’s Dragon and Northrop Grumman’s Cygnus vehicle — to perform reboost demonstrations in recent years. SpaceX’s first such test happened on Nov. 8, 2024.

And on Wednesday, Dragon's efforts got the station to an orbit of 260.9 by 256.3 miles (419.9 by 412 km), according to NASA.

"The new boost kit in Dragon will help sustain the orbiting lab’s altitude through a series of longer burns planned periodically throughout the fall of 2025," agency officials added in the statement.

NASA has said these tests will also be important for another SpaceX job down the road: deorbiting the ISS itself. SpaceX was tasked in July 2024 to bring the ISS down in a controlled fashion when it is time, using a monster Dragon to fulfill the duty.

This particular Dragon arrived at the ISS on Aug. 25, bearing 5,000 pounds (2,270 kilograms) of supplies and science for the orbiting complex and its crew of astronauts. The mission is part of SpaceX's 33rd mission for NASA's Commercial Resupply Services program, also known as CRS-33.

Dragon is expected to stay at the space station until late December or early January, at which point it will head back to Earth loaded with science and discarded items from the ISS. The splashdown zone will be near coastal California.