Falcon 9 ushered in a new age in space tech: reusablity. The ability for the Falcon 9 rocket to reliably land ensures cheaper and reusable rockets, and allows for cheaper space flights in general. Can it get any better than that?

As it turns out, it can—with the reusable space plane.

DARPA is pushing development of its Experimental Spaceplane (XS-1) spacecraft to Phase 2. While Phase 1 was focused on presentation and selection of designs, Phase 2 will be centered around building prototypes. As of now, there are three companies in the running to build XS-1 for DARPA: Boeing, Masten Space Systems, and Northrop Grumman.

XS-1 will reportedly utilize a spaceplane-based launch system. Once airborne, the XS-1 would gain altitude and accelerate to near escape velocity. An expendable upper stage would separate and boost up into orbit to deliver its cargo. The other stage—the actual spaceplane—will do all the heavy lifting. This stage will glide down for a soft landing after the upper stage detaches.

With such a system, DARPA hopes to dramatically cut down the cost of traveling into space. The system even has the potential to make daily launches possible, a milestone that would capture the interest of military and commercial space players alike.

Take a glimpse at the concept plane below.