The United States has spent years touting the Lockheed Martin sourced F-35 as the most advanced combat aircraft ever devised — which resulted in some ruffled feathers when Lockheed pitched an F-35/F-22 hybrid fighter it claimed would be superior to the incredibly expensive (and perpetually troubled) F-35 program. The thing is, despite being chock-full of new tech, the pace of advancement has already exceeded the pace of F-35 production, and it may soon find itself competing in a world full of more capable aircraft — both in terms of what they can do in the physical and digital spheres of warfare.

Here are some of the more exciting aircraft the U.S. military currently has under development, and when we can expect to see them take to the skies.

The B-21 Raider

Northrop Grumman

The B-21, originally named the Long-Range Strike Bomber (LRS-B), is slated to become America’s new go-to long-range infiltration bomber. The platform, which bares an aesthetic resemblance to the B-2 spirit, is steaming toward production rather quietly as compared to higher profile aircraft like the aforementioned F-35, especially considering it’s expected to enter operational service by the mid-2020s.

The B-21 has been developed since its very inception to evade and counter advanced anti-aircraft weapons systems. In theory, the new bomber will take off from American airstrips, fly thousands of miles to through heavily contested airspace undetected, achieve its objective, and head home; providing the United States with a means to deliver ordnance quickly, accurately, and with low likelihood of intercept. The bomber will be capable of carrying both conventional and nuclear payloads and will eventually replace both the B-2 Spirit and the supersonic B-1B Lancer.

Little more is known about the secretive bomber program, and that’s exactly how the government wants it. Even the total pricetag is currently classified for fear that a unit-price may give international opponents some idea of what capabilities are being developed.

SR-72

Lockheed Martin

Unlike the B-21, the SR-72 is still a long way off from any kind of production. Named after the legendary SR-71 Blackbird, which remains the fastest military aircraft ever built despite being retired nearly two decades ago, the SR-72 aims to use advanced scramjet propulsion to achieve hypersonic speeds — currently, only some ballistic missile platforms are capable of such a feat.