Northrop Grumman is recognized across the universe as a leader in space technology. We’ve been Defining Possible above the atmosphere for over 60 years and we’re still leading the way today Designed to provide responsive and low-cost access to space, the Antares rocket is a two-stage vehicle (with optional third stage) that provides low-Earth orbit (LEO) launch capability for payloads weighing up to 8,000 kg. The rocket’s design has been upgraded with newly-built RD-181 first stage engines to provide greater payload performance and increased reliability.