COLORADO SPRINGS, Colo. — Orbital ATK’s entrant in the competition for national security launches has a new name: OmegA.

The project also has a new partner: Aerojet Rocketdyne, which will provide its RL10C rocket engine for OmegA’s upper stage.

Orbital ATK’s update on the rocket formerly known as the Next Generation Launch System came today at the 34th Space Symposium in Colorado Springs.

OmegA is designed to take on intermediate- to heavy-class launches by the Defense Department, civil government and commercial customers. It’s being developed jointly with the U.S. Air Force as an option for future national security launches under the Air Force’s Evolved Expendable Launch Vehicle program.

Orbital ATK and the Air Force have spent a total of $250 million on the development effort over the last three years, and the company said it’s committed to investing even more.

The rocket configuration will make use of solid rocket motors for the first and second stages, plus up to six strap-on solid boosters and Aerojet’s cryogenic hydrogen-fueled upper stage.

Orbital ATK said it’s on track to complete ground tests of the complete propulsion system in 2019, and execute the first OmegA launch in 2021. If the Air Force gives the go-ahead for the next phase of joint development, the company expects to get the rocket certified for operational EELV missions starting in 2022, with the heavy-lift configuration making its debut in 2024.

Charlie Precourt, a former NASA astronaut who now serves as Orbital ATK’s vice president and general manager for propulsion systems, said there’s a lot of commonality between the solid rocket motors used on OmegA and the motors used on boosters for NASA’s heavy-lift Space Launch System.

That could give Orbital ATK an edge when it comes to technical risk and launch cost, Precourt said. “We don’t need to sell many of these to make it work,” he told GeekWire.

Why the capital A at the end of OmegA’s name? Scott Lehr, president of Orbital ATK’s Flight Systems Group, explained the rationale at a Space Symposium gathering to mark the christening. “The O and A at the beginning and end of the name reflect the Orbital ATK name and history of innovation,” he said.

Other launch providers competing for national security launches include SpaceX and United Launch Alliance, which already have been certified by the Air Force.

ULA is working on its own next-generation launch vehicle, known as the Vulcan. Blue Origin, the space venture founded by Amazon billionaire Jeff Bezos, is currently in the lead position to provide its BE-4 rocket engines for the semi-reusable Vulcan rocket.

Blue Origin has also discussed the possibility of getting its own New Glenn rocket certified for national security missions. Both Vulcan and New Glenn are expected to take on their first launches in 2020.