WASHINGTON – Tory Bruno, the president and chief executive officer of United Launch Alliance, the government’s primary launch services provider, has been dribbling out details on the company’s next-generation rocket for weeks.

A formal unveiling of the rocket concept that will eventually replace ULA’s Atlas 5 and Delta 4 launchers is planned for mid-April at the annual Space Symposium in Colorado Springs, Colorado.

In the meantime, Bruno will be taking questions from Reddit users at 7:00 p.m. EDT Thursday as part of the website’s Ask Me Anything series. SpaceX CEO Elon Musk did Ask Me Anything in January.

Below is a primer of what we already know about the new system.

What will the new system be called?

Bruno refers to the new rocket as the Next Generation Launch System or NGLS, but the formal name of the rocket has not yet been decided. The company has received about 300 suggestions for names from ULA employees. That list will be winnowed down and users online will be able to vote for a winner, which will be announced at Space Symposium the week of April 13.

What engines will NGLS use?

Bruno has said ULA is planning on using the BE-4, which is being developed by Blue Origin of Kent, Washington, in partnership with ULA, as the main engine.

If that engine falls behind in development, ULA has a backup plan and could use the AR-1 proposed by Aerojet Rocketdyne. ULA expects to decide in 2016 or 2017 which of the two engines to continue to develop, Bruno has said.

What’s the latest on the BE-4?

Blue Origin, founded by Jeff Bezos, is notoriously secretive. In January, Bruno tweeted that “Blue Origin just finished a very successful powerpack test series at subscale.”

What’s the latest on the upper stage?

This is one area Bruno has kept close to the vest. “We have very exciting plans for the upper stage,” he said on Twitter. ULA has long worked with XCOR on a liquid-hydrogen concept. ULA is also working with Aerojet on an upper stage engine, Bruno confirmed. But in a recent interview with SpaceNews he also said other companies are involved in upper stage work.

What about the rest of the rocket?

Bruno told spaceflightinsider.com that ULA is developing the first stage, followed by the upper stage and then other subystems. “We have just started wrapping up some of those trades,” he said.

When will NGLS launch?

Bruno has said repeatedly the first flight is expected in 2019 if all goes as planned. The certification necessary to launch Air Force satellites would take several years.

Where will NGLS launch?

ULA’s plan is to downsize from the five launch pads it maintains between Cape Canaveral Air Force Station in Florida and Vandenberg Air Force Base in California to just one pad at each location. Bruno said the company is still completing the trade studies on the infrastructure it would need, but has informed the Air Force of its long term plans.

Where will ULA build NGLS?

Not clear. But Bruno told the Decatur Daily that “Blue Origin is off right now with our team doing studies … on where that facility should be, and I can tell you that Alabama and certainly the Decatur area is within the (area) that’s being looked at right now. But I don’t know what the answer will be.”

Who is paying for NGLS-related development activities?

Bruno told SpaceNews that between Aerojet-Rocketdyne, Blue Origin and ULA, the three companies have “identified” $1 billion in private investment.

Will NGLS replace the company’s current rockets, the Atlas 5 and Delta 4?

Eventually, yes. ULA hopes to phase out the Atlas 5, in large part, because of a Russian engine known as the RD-180 that powers the rocket’s first stage.

The company also has told the Air Force it plans to phase out all but the heavy-lift version of its Delta 4 rocket as early as 2018 and will continue building the Delta 4 Heavy as long as its Air Force customer desires.