Northrop Grumman’s B-21 bomber program has, in many ways, proven to be quite stealthy already. As development has progressed in recent years, Air Force officials have paraded out the same artist’s rendering of the aircraft to accompany statements about its progress, offering little in the way of details beyond the fact that it is indeed progressing, and if we’re to take them at their word, it’s progressing on time and on budget—a relative rarity among such large-scale defense undertakings.

In the most recent go-round with Air Force officials, however, the news was a bit more interesting: Not only is the B-21 progressing, but according to recent statements made by Lt. Gen. Arnold Bunch, the Air Force’s military deputy to the Office of the Assistant Secretary for Acquisition at the Pentagon, the “next major milestone is first flight” for the secretive bomber.

“We’re still in our acquisition thresholds and baselines, and [the B-21] is executing the way we want. We got past critical design review,” he told a Senate Armed Services subcommittee on Tuesday, according to Business Insider.

The last we heard about the B-21 program, it had passed the critical design review milestone in December of last year, the last major hurdle between what some call a “paper plane” (or an aircraft that exists in design only) and an aircraft that can be built for testing.

“The Air Force is pleased with how the program is moving forward,” said Air Force Secretary Heather Wilson in December. “The B-21 Raider program is on the right track to make continued progress over the next few years as it now transitions from the design phase into a robust manufacturing phase that will ultimately produce our first B-21 test aircraft.”

Beyond reports of steady progress, however, little is known for certain about what promises to be America’s deep-penetration bomber throughout much of the 21st century. Thus far, we know the Air Force intends to procure at least 100 of these bombers, which are slated to replace both the B-2 Spirit (sometimes known colloquially as the “Stealth Bomber”) and America’s only supersonic-capable heavy payload bomber, the B-1B Lancer. Despite that, it seems unlikely that the flying wing design of the B-21 will be a supersonic-capable platform.

The Air Force has consistently said that they expect the B-21 to enter initial combat operations as soon as the mid-2020s, meaning they expect to be through the majority of testing within the next six years—a lofty goal for a program that, at least officially, has yet to produce a single airframe for actual testing.

The question is, with the B-21’s first flight expected sometime in the near future, will the public get its first glimpse of the new bomber? Edwards Air Force Base in California has been chosen as the site to support testing of the B-21 Raider, though it’s unclear if that means the Air Force expects to use that base for the bomber’s first flights. The airstrip in the dry lake bed of Groom Lake, located on the Nevada Test and Training Range and commonly referred to as Area 51, has also had a large new hangar built along its airstrip within the past two years, suggesting the B-21 may join the likes of the F-117 Nighthawk and SR-71 Blackbird on the list of advanced aircraft tested at the secretive installation.