Update May 9, 1:27 p.m. ET: Information from Wired.com aviation correspondent regarding Scaled’s first unmanned aerial vehicle was added to the bottom of the story.

Hauling tourists into space — that’s for tomorrow. Today, the legendary aerospace designers at Scaled Composites are unveiling a new spy plane that can snoop four different ways on the unsuspecting, and doesn’t need a human in the cockpit to fly.

Scaled Composites is best known for its private spacecraft, like the one Virgin Galactic plans to use to take well-heeled tourists into orbit. But Scaled is also a division of the giant defense contractor Northrop Grumman. So Richard Branson isn’t the firm’s only customer.

On Feb. 9, 2009, Northrop executive Rick Crooks called Scaled president Doug Shane with an idea for a new military surveillance aircraft: one that could swap out sensors as easily as thumb drives, and could fly with a pilot onboard — or not. Exactly one year later, that aircraft, dubbed “Firebird,” made its first test flight.

Last week, pictures of the plane were taken from Beale Air Force base in California, and then leaked online. Now, Scaled and Northrop are introducing the plane to the public, just before it takes part in a Pentagon war game, the Empire Challenge 2011.

Like many of Scaled’s designs, the 34 foot-long, 5,000-pound Firebird doesn’t look like a typical plane. It’s got these twin booms in the back, which allow sensors and antennas to be carried away from the main fuselage; they also make it easier for the plane to take off and land on the sorts of rugged runways you might find in a war zone.

But Crooks says the most interesting part about the Firebird is what’s inside. The plane can carry a bundle of up to four different electronics packages — a combination of high-resolution cameras, synthetic aperture radar (SAR), communications relays or eavesdropping gear.

Those gadgets are carried in racks inside the plane, rather than on pods hanging off of the wings. They’re joined together by a network that’s separate from the one used to fly the plane. That means the gear can be swapped out easily, rather than going through years of testing in flight certification.

“The airplane becomes a bus, providing a rise for whatever sensor,” Crooks tells Danger Room. “It takes days or weeks to get a new payload integrated, instead of years.”

The Firebird can fly at up to 30,000 feet for anywhere from 24 to 40 hours, Crooks figures. It can also turn from a standard plane to a drone, pretty much instantly. That’s useful because the federal government remains skittish about letting drones fly in American airspace unattended. Over Afghanistan, though, that’s a different story. Tricked-out executive jets join Reaper unmanned aerial vehicles and robot blimps in the skies, and they all stare down on what’s below.

The Firebird won’t be joining them anytime soon — it’s a Northrop demonstration vehicle, not a military-sponsored aircraft. But Crooks says its “ready to conduct missions” right now. Meanwhile, Scaled Composites’ SpaceShipTwo is in the middle of glide tests. If all goes well, it’ll take its first gaggle of gawkers into orbit some time in 2012.

Firebird isn’t Scaled’s first unmanned aerial vehicle, according to Wired.com’s aviation correspondent Jason Paur. That would be the Proteus, which was planned as “an ultra low-level satellite-type relay,” says Paur by e-mail. “The airplane was designed to orbit at around 65,000 feet for more than 15 hours at a time over a city with a dish that would relay communications.”

Paur adds that the antenna dish was mounted at a tilt on the fuselage so it would be level during the constant banking circle the airplane would fly, and the wing tips were dielectric to avoid any interference. The idea was that it could be higher bandwidth and cheaper than a satellite, and the technology inside could be changed whenever needed.

Three of the aircraft were to be used in rotation for 24/7 coverage. That idea was never realized, but the earlier plane has been proposed as a UAV, and Northrop has been using it extensively for testing many high-altitude observation and communication ideas.