The Pentagon is, once again, reversing its own position on which platform to use for its high-altitude reconnaissance mission – the venerable U-2 or Global Hawk unmanned aircraft.

The Office of the Secretary of Defense (OSD) has directed the U.S. Air Force to restart modest funding not only for operations of the high-flying U-2, but also to invest some funding in research and development and procurement, according to industry sources. The funding is coming from a topline increase for the service, meaning OSD has provided the cash to pay for it, and is slated for inclusion in the fiscal 2016 budget request going to Congress next month.

The roughly $150 million in investment spending over three years is a signal that last year’s proposal to retire the U-2 fleet and quickly transfer the high-altitude collection mission to the unmanned Northrop Grumman RQ-4B Global Hawk was a bridge too far. It shows that the service will not only operate the fleet it has, but pay for upgrades to keep the U-2 relevant. In addition, funding for U-2 operations will be restored for three more years – fiscal 2016-18, the sources say. Though operations at the height of the Iraq and Afghanistan wars ran about $400 million annually, the service is now targeting about $350 million a year to operate the U-2 globally.

A congressional staffer says keeping the U-2 and Global Hawk will "please everyone" on Capitol Hill. So this move is, perhaps, a concession to lawmakers on one of the less contentious proposals being reviewed now in the fiscal 2015 budget request. Among the other unpopular pitches by the Air Force last year was a plan to retire the A-10, for example.

The Air Force declined to provide a rationale for the move. "All this is pre-decisional until the president’s budget is signed," a service spokeswoman says.

This is the latest twist in 15 years of tit-for-tat funding raids between the Lockheed Martin U-2 and the Global Hawk. Less than three years ago, the Air Force offered up Global Hawk for termination; the plan was to kill the Block 30 version of the aircraft. This is the variant capable of collecting imagery as well as conducting radar and signals intelligence. The Block 40 aircraft, outfitted with a large radar to monitor ground traffic, was expected to be next up for the ax once the Block 30 termination was approved.

Northrop Grumman lobbied hard for the aircraft; the Air Force Global Hawk is the foundation for the U.S. Navy’s Triton program as well as for international pursuits. And, Pentagon officials said last year that the company substantially improved its Global Hawk operating cost, convincing them that the system should be retained over the U-2.

The decision to keep the U-2 appears to be a last-minute shift in the budget. Only last November, Pentagon procurement chief Frank Kendall said the debate between the two was settled. "It was settled by Northrop Grumman getting the sustainment costs of the Global Hawk below what some people thought they were going to be. And that made Global Hawk a better business case than the U-2," he told Aviation Week in an interview. The Air Force is facing a bill of $1-3 billion, however, for Global Hawk improvements designed to reach U-2 parity. These include adding an all-weather capability and improvements to the ground station and addressing obsolescence issues.

When the Pentagon decided last year to mothball the U-2 in favor of transferring the high-altitude mission to the Global Hawk, combatant commanders raised a stink. The Global Hawk is the only UAV specifically assigned to take over the role of a manned aircraft, and this waffling at such senior levels of the Pentagon shows that while leaders want to embrace the persistence of a UAV, it comes at a cost of unpopular operational drawbacks.

Though a capable platform, the Global Hawk carries 3,000 lb. of sensor payload compared to the U-2’s 5,000 lb. The Global Hawk typically flies at 55,000 ft.; the U-2, by contrast, flies well above 70,000 ft., offering a substantially better look angle. And despite substantial improvement in processing the imagery from the Raytheon Enhanced Integrated Sensor Suite on the Global Hawk, some intelligence officials say commanders still prefer U-2 products.

The infusion of research and development and procurement products – even with a modest amount – will likely be earmarked largely for sensor work. U-2 advocates hope to improve the Advanced Synthetic Aperture Radar System (Asars), made by Raytheon. Though updated, program supporters hope to add an improved ground moving target indication capability.

Additionally, the program is using two new Senior Year Electro-Optical Reconnaissance Systems (Syers) among the fleet; these offer improved spectral diversity by collecting imagery in 10 bands rather than six. Syers is produced by United Technologies Aerospace Systems, formerly known as Goodrich, and the additional collection bands are optimized for use in the maritime environment. The hope is to buy six more upgraded Syers, the industry source says.

The U-2 has also been used to carry the "Dragon Fly" communication gateway to relay full-motion video out of Syria and Northern Iraq. A more advanced version of this system has been developed by L3 Communications and could be added to the platform, the source says. The U-2 can combine this communication gateway mission using Dragon Fly and imagery collection with the same platform. These missions are done on separate Global Hawk aircraft – the Block 20 carrying its communications gateway and the Block 30 collecting imagery.

Work could also restart on upgrades for the U-2’s defensive suite, which is developed by BAE. The Global Hawk lacks its own defensive system.

This waffling between the two platforms is happening in public, while privately the Air Force is planning to field the RQ-180, a stealthy, penetrating intelligence collection platform. Developed under a secret contract with Northrop Grumman, the RQ-180 could be operational as soon as this year. It is possible that once the RQ-180 is fielded, the service might have a better argument to mothball the U-2 or Global Hawk.