Orbital ATK’s newly redesigned Antares rocket is set to make its spaceflight debut on August 22nd. That’s when the vehicle is scheduled to take off from NASA’s Wallops Flight Facility in Virginia and carry the company’s Cygnus cargo capsule to the International Space Station. In May, Orbital said the flight would occur in July, but last month, the company said the launch had slipped to August. If all goes well, it will mark the first flight of the Antares in nearly two years. The vehicle has been grounded since October 2014, when a previous version of the rocket exploded mere seconds after launch.

The accident prompted Orbital to refurbish the Antares rocket

That accident prompted Orbital to refurbish the Antares rocket. The company conducted an investigation into the issue, concluding that the problem started in one of the rocket’s two AJ26 engines, which are made by manufacturer Aerojet Rocketdyne. There’s been some dispute over whether or not Aerojet is to blame for the explosion, but Orbital opted to replace the engines in the Antares regardless. So for the past two years, the company has been working to replace the Antares’ AJ26 engines with two RD-181 engines, which are made by Russian company NPO Energomash.

As Orbital refurbished the Antares, the company still needed a way to launch cargo into space, since it holds contracts with NASA to periodically resupply the ISS through 2024. So as a stopgap measure, Orbital turned to the United Launch Alliance for help. For the company’s last two resupply missions, Orbital launched its Cygnus cargo capsules on top of ULA’s Atlas V rockets, allowing the company to keep fulfilling its contractual obligations to the space agency.

With this upcoming launch, Orbital will be using its own rockets once again. This will mark the sixth cargo resupply mission for the company, and the fourth one with the Antares.