U.S. AIR FORCE IS PLANNING SOMETHING BIG IN THE NEVADA DESERT: Unusually worded, multi-billion dollar drone services contract possibly points to a new, shadowy unmanned aircraft—and a lot of them.

This contract with URS Federal Services is worth $3.6 billion, but the program, whatever it is, isn’t expected to end until the spring of 2034. That’s 17 years for those keeping score. The math works out to more than $210 million per year, on average, over that period or $17.5 million every month.

That’s a big price tag for services. In 2013, the RAND Corporation estimated that it cost $435 million a year for the Air Force’s 20th Fighter Wing at Shaw Air Force Base in South Carolina to operate three squadrons of F-16C/D Vipers. This calculation included everything associated with flying the fighter jets, such as pay checks for military personnel and supporting contractors, fuel, depot-level repairs, as well as indirect support from the Wing’s other elements, including security forces guarding the flight line, civil engineers maintaining facilities, and basic utilities and supplies, such as electricity in the barracks and food in the chow halls. A similar analysis of the 187th Fighter Wing, a unit in the Alabama Air National Guard with just one squadron of Vipers, produced a final price tag of just $63.6 million.

In short, the URS Federal Services’ contract could potentially cover the full costs of running multiple squadrons of pilotless planes for nearly two decades. And remember that this deal likely only pays for just a portion of the total cost of this project. So, while we don’t know what unmanned aircraft—singular or plural—the Maryland-based company will be helping test, the money involved here suggests there are quite a few of them.

The Air Force has since backtracked on exactly what kind of contract was awarded to URS, but not the total amount. Given the long history of secret USAF activities in and above the Nevada desert, there’s no telling what’s URS has been hired to do.