Sometime in the next few years the world’s most sophisticated drone prototypes will likely face off in what could be a multi-billion-dollar competition to shape the future of air warfare. And now we finally know what all four contestants look like.

On Friday, number-one defense contractor Lockheed Martin released the first official teaser image of its Sea Ghost jet-powered killer drone. Along with previously disclosed unmanned aerial vehicle designs from rivals Boeing, Northrop Grumman and General Atomics, the Sea Ghost will go head-to-head for a Navy contract to put fast, stealthy, missile- and bomb-armed drones on the decks of aircraft carriers by 2018.

Plus, the Air Force is considering also buying whichever UAV the Navy picks for the so-called Unmanned Carrier Launched Airborne Surveillance and Strike requirement. The ‘bot that comes out on top in UCLASS could dominate the pilotless warplane business for a generation.

Last week’s image, featured above, is deliberately vague but seems to confirm what aerospace observers widely suspected. The Sea Ghost, in development for several years, is a tailless flying wing — similar to a miniature B-2 stealth bomber. That means it’s got radar-evading qualities but is potentially difficult to control in flight, as it lacks the vertical stabilizers most planes possess.

It also means the Sea Ghost shares engineering philosophies with Boeing’s and Northrop’s UCLASS contestants, both of which boast roughly 50-foot wingspans. Boeing hasn’t officially publicized its ‘bot, but the company has recently flown the latest version of its X-45 killer drone, a flying wing with design roots stretching into the 1990s. Most observers expect Boeing to tweak the X-45C with tougher landing gear and other special modifications for carrier ops.

Northrop, for its part, is already testing copies of its X-47B, another flying-wing design and a rough contemporary of the X-45. The X-47B has flown land-based test flights in California and, as of this weekend, in Maryland — all under a separate Navy demonstration contract. The Northrop UAV is slated to perform the first carrier launch of a jet-powered drone warplane sometime next year.

That leaves General Atomics as an outlier with its Sea Avenger, a sort of grown-up version of the MQ-9 Reaper but with a jet engine in place of the Reaper’s propeller. The Sea Avenger has swept wings and vertical tails, just like today’s manned, carrier-based fighters. General Atomics’ drone could be the conservative option. “Avenger provides the right capabilities for the right cost at the right time,” company president Frank Pace said.

The Sea Ghost’s general outline can be deduced from the teaser image. Beyond that, Lockheed’s not revealing much at the moment. “Sea Ghost … leverages … experience with the RQ-170 Sentinel Unmanned Aircraft System, the Joint Strike Fighter F-35C and other Navy program technologies,” the company said on its website.

The F-35C ties are no-brainers: the Sea Ghost could share water-resistance stealth coatings and other radar-defeating techs such as special antennas with the Navy version of the too-big-to-fail Joint Strike Fighter.

But the Sea Ghost’s connection to the marginally-stealthy RQ-170 is perhaps more surprising — as is Lockheed’s eagerness to tout the relationship. The RQ-170 is most famous for winding up in an Iranian gymnasium after one crashed mostly intact on the Iran-Afghanistan border in December, presumably while spying on Tehran’s nuclear program. Every few months since then, the Iranian government has loudly claimed to have copied some of the RQ-170′s secrets.

On the other hand, the RQ-170 is also an all-wing design and could help Lockheed refine the delicate algorithms necessary for controlling a tailless aircraft in tough flying conditions.

Amid all this speculation, it’s actually possible we’ve already seen the Sea Ghost — albeit from great distance. Last month, blogger George Kaplan highlighted a commercial satellite image, dated December, that depicted what appeared to be a new kind of flying-wing UAV at a Lockheed facility in California.

Melissa Dalton, a Lockheed spokesperson, said the thing in the photo was part of a research project looking into “different shapes and materials for both manned and unmanned vehicles.” But she didn’t specify which unmanned vehicles, leaving open the possibility that Sea Ghost’s debut actually occurred six months ago.

In any event, the lineup is complete. The four candidates for America’s future killer drone are either already flying or preparing to take to the air. Sometime in next few years, the lethal flying ‘bots will battle each other in a battery of Navy tests as the Air Force looks on. And by 2018 under current plans, the winner will takes its place on the front lines of autonomous warfare.