Aerojet, a GenCorp Inc. [GY] company, is participating in NASA’s Space Launch System (SLS) advanced booster competition as a way to evaluate some “very promising” engine architectures.

Aerojet Vice President of Space and Launch Systems Julie Van Kleeck said in an interview recently the company’s Full-Scale Combustion Stability Demonstration offering could provide savings to both NASA and international customers.

“We believe this NASA Research Agreement is a way for the evaluation of some very promising engine architectures that could provide some real affordability benefits to NASA and potentially other customers in our country,” Van Kleeck said. “We’re looking at it as a first step in a process. We’re not looking at it as an end to itself.”

Aerojet is offering a liquid propulsion device for the advanced booster. Van Kleeck said through a spokeswoman liquid devices use a set of rocket engines attached to the base of some tanks, which feed the engines and are controlled by valves commanded from the main vehicle. The propellants, kerosene and oxygen, burn in the engines’ thrust chamber, which can vary its power up and down and also be commanded off.

Van Kleeck said, in contrast, a solid engine booster is a large segmented device that is ignited and burns throughout the entire device. Van Kleeck said solid boosters cannot be actively controlled or turned off.

Van Kleeck said a liquid device is commonly used for launches, although she said the United States has been using large solid rocket motors in this function on the Space Shuttle, which flew 135 missions over 30 years.

NASA selected six proposals from four companies, including Aerojet, to help improve the affordability, reliability and performance of an advanced booster for SLS. The awardees will develop engineering demonstrations and risk reduction concepts for the SLS, which is a heavy-lift rocket that will provide a new capability for human exploration beyond low Earth orbit.

NASA is currently negotiating specific awards with offerors and may spend as much as $200 million among the six proposals. Van Kleeck said Aerojet will spend the next “several weeks” negotiating and if Aerojet is successful, she “anticipates” an award. Van Kleeck also said believes all proposals are fixed-price tasks.

“I think we’re both working toward a start in October, so it’s our hope we’ll complete negotiations over the next month and a half or so,” Van Kleeck said.

Successful offerors to this Research Agreement are not guaranteed any future advanced booster acquisition awards, NASA said.

Northrop Grumman [NOC], ATK [ATK] and Dynetics Inc., have also been selected by NASA to participate in SLS advanced booster contract negotiations.