GAO identified 15 key aerostat and airship efforts that were underway or had been initiated since 2007, and the Department of Defense (DOD) had or has primary responsibility for all of these efforts. None of the civil agency efforts met GAO's criteria for a key effort. Most of the aerostat and airship efforts have been fielded or completed, and are intended to provide intelligence, surveillance, and reconnaissance (ISR) support. The estimated total funding of these efforts was almost $7 billion from fiscal years 2007 through 2012. However, funding estimates beyond fiscal year 2012 decline precipitously for aerostat and airship efforts under development, although there is an expectation that investment in the area will continue. Three of the four aerostat and airship efforts under development, plus another airship development effort that was terminated in June 2012, have suffered from high acquisition risks because of significant technical challenges, such as overweight components, and difficulties with integration and software development, which, in turn, have driven up costs and delayed schedules. DOD has provided limited oversight to ensure coordination of its aerostat and airship development and acquisition efforts. Consequently, these efforts have not been effectively integrated into strategic frameworks, such as investment plans and roadmaps. At the time of GAO's review, DOD did not have comprehensive information on all its efforts nor its entire investment in aerostats and airships. Additionally, DOD's coordination efforts have been limited to specific technical activities, as opposed to having a higher level authority to ensure coordination is effective. DOD has recently taken steps to bolster oversight, including the appointment of a senior official responsible for the oversight and coordination of airship-related programs. However, as of August 2012, DOD has not defined the details relating to the authority, scope, and responsibilities of this new position. Whether these steps are sufficient largely depends on the direction DOD intends to take with aerostat and airship programs. If it decides to continue investing in efforts, more steps may be needed to shape these investments.