NASA/Stephanie Stoll
The launch was originally scheduled for spring, but was set back due to a potential issue with the spacecraft's software.
The crew includes astronauts from three different space agencies: NASA astronaut Kate Rubins, veteran Russian cosmonaut Anatoly Ivanishin, and former Japanese airline pilot Takuya Onishi of the Japan Aerospace Exploration Agency.
Rubins, who has a Ph.D in cancer biology, is the first female astronaut the ISS has seen since 2015. Once there, she will work on scientific research, becoming the first person to sequence DNA in space.
The astronauts will be riding in an upgraded version of Russia's Soyuz rocket. The rocket has new redundant thrusters and electrical motors for the vehicle's docking probe, NASA said. It also has extra photovoltaic cells on its solar panels and additional shielding against micrometeoroid debris. To top it off, the Soyuz has a new video transmitter, updated communications capabilities, and a better satellite navigation system.
Although Soyuz flights to the ISS usually take just six hours, this trip will take about two days - the trio isn't expected to arrive at the space station until shortly after midnight on Saturday. This extra time will allow the crew to test out some of the upgrades made to the Soyuz rocket.
The spacecraft will complete 34 orbits around Earth before docking at the ISS at 12:12 am ET. Two hours after docking, the hatch will open and the astronauts will join NASA astronaut Jeff Williams and Russian cosmonauts Oleg Skripochka and Alexey Ovchinin. They are expected to stay on board until October.
You can watch the launch live on NASA TV or below: