There has been a lot of talk about government partnerships with commercial entities at the 33rd annual Space Symposium in Colorado over the last two days, not least of which was the announcement that Orbital ATK is in major standing to compete for a US Air Force contract for a new rocket system to deliver payloads to space. New Atlas was on hand to talk to the company to get more of the story.

The program for which Orbital ATK will be building its largest rocket ever, dubbed the Next Generation Launch system (NGL), was initiated by the Air Force to replace the Russian-built RD-180 rocket for the delivery of national security payloads such as GPS satellites and missile-warning systems to outer space. In the first phase of the project, the Air Force requested a new rocket-propulsion system, and Orbital ATK obliged by developing a solid-fuel-based system. According to Mike Laidley, vice president of Space Launch Programs, the company leveraged its experience building propulsion systems for the space shuttle to achieve success.

"We've taken those designs which were steel-case segmented section and we've updated the design and the manufacturing processes to be a composite-segmented case that's wound on a mandrel," he told us, adding that the material used was be a carbon-fiber composite. "It will be poured and built up, and the segments will be assembled at the field site to create a rocket that will support our launch vehicle." By "poured," Laidley is referring to the insertion of the fuel – which he describes as a thick cake batter consisting of ammonium perchlorate and other binders – into the segments.

The solid-fuel rocket motor case from Orbital ATK Orbital ATK

The first two stages of the rocket will consist of the solid fuel, while the third-stage will use liquid hydrogen.

Laidley said the case thickness varies in length from about a half inch to an inch thick (about 1.2-2.5 cm) and that the first one was just cured about a week ago. It will be used to qualify the design. "In other words, we're going to take it and we're going to bend it, and we're going to break it and pressurize it and do all kinds of things to verify that its integrity meets the design we expect it to," he said.

Orbital ATK is planning on producing two rockets: a 500 series, which will have a payload fairing of 5 x 15 m (16 x 49) and will measure 73 m (239 ft) long, and a 500XL series, which will have a fairing of up to 5 x 20 m. The rockets will be able to carry between 5,500 to 8,500 kg (12,125 - 18,739 lb) of cargo into geosynchronous orbit, and the engines will measure 3.7 m (12 ft) in diameter and 12 m (40 ft) long. Laidley says the engines, known as CASTOR 300 and 600, fit nicely on a basketball court.

As the next step in the process, the Air Force will select three companies to move forward next year, and then in 2019, the list will be whittled down to two companies capable of meeting all of its needs.

The next phase in the development of the rockets for Orbital ATK is a static fire test in 2019, followed by certification flights in 2021, if the company is chosen.