WASHINGTON – U.S. government launch services provider United Launch Alliance has completed the conceptual trade studies for its revamped Atlas 5 rocket and plans to unveil details in April, Tory Bruno, the company’s president and chief executive said Jan. 22.

ULA is working with Blue Origin, the secretive rocket-making venture led by Amazon.com founder Jeff Bezos, to develop a new engine, dubbed the BE-4. That engine would replace the Russian-made RD-180 that powers the first stage of ULA’s Atlas 5 rocket.

The company’s announcement would come at the Space Foundation’s Space Symposium, one of the space industry’s largest trade shows, being held April 13-16 in Colorado Springs, Colorado (full disclosure: SpaceNews is a Space Symposium media partner).

@Gruss_SN Yes. The top level trades are done. Planning to roll it out at the Space Symposium — Tory Bruno (@torybruno) January 23, 2015

Bruno told SpaceNews in October that using the BE-4 engine would require significant changes to the current Atlas 5 configuration.

We’re going to have to change the booster, the first stage, to accommodate that. Because of the density difference we’re going to need a larger tank. We’re going to have a larger diameter tank that may or may not be longer.

There will be software modifications to accommodate the different performance and timing because this engine is going to produce a lot more thrust than we currently have with our RD-180.

But beyond that it’s all the same. My vision is to update the technology. The trades for what that vehicle family looks like are still underway and they’ll be completed about the end of the year.

Bruno also is scheduled to speak at the Stanford Student Space Initiative Feb. 4 and said on Twitter he would be discussing reusability, a hot topic in the industry since SpaceX has tried to land the first stage of its Falcon 9 rocket on a floating platform in the Atlantic Ocean.