For the first time in more than 30 years, the United States Air Force is unveiling a new stealth bomber. The B-21 Raider is expected to be shown to the world Friday.

The next-generation stealthy long-range strategic bomber is designed to eventually replace the ageing B-1 Lancer and B-2 Spirit aircraft and become the backbone of the US Air Force’s bomber fleet.

Remarkably for a large weapons programme, the B-21 has come in on time and reportedly within the $25.1bn budget the US Air Force allocated it in 2010. Northrop Grumman, which has been developing the bomber, appears to have learned from lessons that befell previous high-profile programmes like the F-35 and the B-2 bombers.

The 34-year-old B-2 Spirit was a generation ahead of its time. The advanced materials coating the aircraft, combined with the shape of the airframe and engine inlets, meant its radar signature was minute, rendering it virtually “invisible” to radar.

This allowed the aircraft to conduct long-range strike missions in highly-defended areas with a good chance of surviving the mission, something other bombers, like the B-1 and the venerable B-52 would have little chance of succeeding at.

Undetected, the B-2 can already destroy high-value targets deep in enemy territory with little to no warning.

So what makes its successor, the B-21, so special?

More of the same?

The programme has been highly classified and Northrop Grumman has released few details about the project, but some information has trickled out in published reports.

The B-21 Raider clearly draws a lot of its designs from its predecessor, such as the flying wing concept with its engines embedded and configured to efficiently reduce its radar signature.

The airframe is slightly smaller than the B-2: its payload – the amount of ordinance, bombs and missiles it can carry – is almost halved.

It is not particularly fast – designed to fly at high subsonic speeds – and it is not the quantum leap the B-2 stealth bomber was when it was first introduced in 1988.

It is, however, significantly cheaper, both to buy and maintain. The B-2 was horrendously expensive to keep airworthy and the B-21 will greatly lower the toll in money and man-hours needed in its upkeep. Cheaper planes are more likely to be bought in higher numbers. A hundred aircraft have initially been slated for production with that figure likely to rise if costs can be kept down.

What’s new?

While stealth is a chief attribute, it is by no means the B-21’s only quality. What the Air Force, and the US military as a whole, have been working to build is a powerful, distributed network of long-range sensors and strike platforms that transmit and share vast amounts of data about the enemy they are fighting.

The B-21 fits into this new strategy network perfectly, able to gather intelligence about a potential enemy or area and to carry out a strike. In other words, it can gather and relay information to friendly aircraft, satellites, radars and more, and it is also an offensive weapon, able to destroy targets within its range.

Long-range strikes may be its primary mission but the B-21 bomber will be able to gather and share intelligence, helping direct its own fleet of weapons that can in turn destroy multiple targets. In short, its “brain” is its most valuable asset and the use of open-source software will allow the aircraft to be easily upgraded – ensuring it remains flexible and cutting-edge while seriously extending its useful life.

The aircraft can be flown in a manned and unmanned configuration and its internal weapons bays will allow it to carry the latest long-range stealth missiles like the JASSM (Joint Air to Surface Stand-off Missile) as well as other conventional and nuclear payloads.

Stealth under threat?

These attributes are all vital if the aircraft is going to survive. There are already reports that advances in quantum radar may allow stealth aircraft to be detected. China claims to have fielded a radar its military says can detect the stealthiest aircraft, an assertion rejected by Western experts.

Still, this is an area of intense focus especially given the obvious military applications. For decades, stealth aircraft have dominated the skies, so with a quantum radar that actually worked, the significant advantages US stealth aircraft have enjoyed would disappear overnight. Normally unseen and invulnerable aircraft could be detected and shot down.

Even without stealth, the B-21s’ other attributes are what makes it such a deadly aircraft. It can absorb information at a far greater rate than its rivals – meaning it will know where the enemy is and where its own assets are – fitting into a vast framework of deadly platforms that will be able to destroy their targets from a long way off.

This ability to gather, absorb and assimilate vast amounts of data, the B-21’s extended means to keep being updated, and its every sensor being the latest and most powerful is what will make the Raider the potent weapon it has been designed to be.

The B-21’s rollout on Friday means the start of years of development, tweaking, refining and fine-tuning as the bomber undergoes constant tests, first on the ground and then in the air under a vast variety of conditions (before it will be finally inducted into the US Air Force).

But it is already under way to being one of the weapons any potential adversary will fear most as there would be little to no warning of its arrival deep inside an enemy’s air space. It is this deterrent factor that will be part of the thought calculus of any near competitor when considering military action.

China, having seen the United Stated field stealth bombers for decades, has now sped up research into building its own, the Xian H-20 stealth deep-penetration bomber. The B-21 Raider will have its challengers.