Gary Zhou 
Key Points
- 🚀 Northrup Grumman’s Antares 230+ rocket will launch its final resupply mission to the International Space Station at 8:31 p.m. ET.
- 🛰️ The rocket will carry the Cygnus cargo vehicle with 8,200 lbs of supplies and experiments.
- 💥 Antares previously had a failure on its 5th mission due to a liquid oxygen turbopump issue, leading to a switch to RD-181 engines.
- 🚀 Northrup Grumman is working on the Antares 330 rocket, which is expected to launch by Summer 2025.
- 🌐 The current weather outlook shows an 80% chance of acceptable conditions for lift-off, and NASA will stream the launch on YouTube.
Tonight at 8:31 p.m. ET (00:31 UTC on the 2nd), the Northrup Grumman Antares 230+ rocket is set to embark on its final resupply mission to the International Space Station (ISS).
The launch will take place from Launch Pad 0 at the Mid Atlantic Regional Spaceport located on Wallops Island, Virginia. The rocket will carry the Cygnus cargo vehicle, which will be loaded with an impressive 8,200 lbs (3,719 kg) of supplies and experiments destined for the orbiting outpost.
Since its debut in April 2013, the Ukrainian-built Antares launch vehicle has been exclusively utilized for resupply missions to the ISS. However, it encountered one failure during its missions, leading to its first upgrade.
Initially, the rocket used NK-33 engines that were originally developed by the Soviet Union in the 1970s. These engines were later acquired by Aerojet-Rocketdyne, modified, and renamed as the AJ-26 engines, which became the propulsion system for the Antares rocket.
On the rocket’s 5th mission, one of those engines failed in spectacular fashion when a liquid oxygen turbopump with manufacturing defects failed 6 seconds after liftoff, causing Antares to fall back down onto the launch pad and explode.
This set off a chain of events for U.S. launch providers as the United States banned further purchasing of Russian-made engines in December 2014, a decision that was altered just a year later to accommodate United Launch Alliance, whose Atlas V rocket uses Russian-made RD-180 engines.
Following the failure, Antares was switched over to using the RD-181 engines and thus creating the next Antares variant, the 230 series of the rocket. This version would go on to launch 12 more times before the Russian invasion of Ukraine, and the resulting sanctions against Russia forced Northrup Grumman to end its reliability on the Ukrainian-built first stage and Russian engines.
In August 2022, Northrup Grumman announced they had contracted Firefly Aerospace to produce a new medium-lift rocket for the company that will be called the Antares 330. The 330 series will use 7 Miranda engines from the company. The 330 series upper stage will be the Castor 30XL solid-fueled rocket motor, with later versions using a vacuum-optimized Miranda engine to provide extra performance.
While the Antares 330 rocket is being designed and built, Northrup Grumman has contracted SpaceX to launch 3 Cygnus resupply missions in order to fulfill their contract with NASA.
Northrup Grumman has said they expect to be able to launch the Antares 330 by Summer 2025.
The current weather outlook shows an 80% chance of acceptable conditions at lift-off. NASA will host a live stream of the launch on its YouTube page.
