FIGURE S.1 Overhead photo of the High Frequency Active Auroral Research Program Gakona Facility. SOURCE: McCarrick, M., et. al., Marsh Creek LLC, “HAARP Facility Status,” presentation to the Committee on the Role of High-Power, High-Frequency-Band Transmitters in Advancing Ionospheric/Thermospheric Research: A Workshop, April 2013. Courtesy of M. McCarrick. Available at

ionosphere, and the magnetosphere. These regions form a coupled system whose nonlinear response to variable and wide-ranging energy and momentum sources have important influences on those of us living on the surface of Earth; for example, radio and satellite communications, global navigation, and the lifetime of space assets limited by atmospheric drag. Many participants in the workshop, even some who were familiar with experiments at heater facilities, said they came away with an increased appreciation for the breadth of phenomena that are addressed by the HAARP facility.

Historically, military applications have been a major motivation for studies at HAARP. At the workshop, the Navy’s interest in HAARP was attributed to the prospects to use the ionosphere as an antenna to generate extremely low-frequency (ELF) waves for global submarine communication, while the Air Force interest included applications such as over-the-horizon radar and attempts to study the effects of injecting ULF, ELF, and VLF waves into the radiation belts in order to affect the lifetimes of “killer” million-electron-volt electrons that would otherwise disable low Earth orbit satellites.6 Those applications were not widely discussed in this unclassified workshop, although some of them are mentioned in Chapter 4.

Some participants at the workshop cited the unusual history of the HAARP facility as a contributor to its underutilization by a broader community of researchers. In particular, they noted that initial funding for HAARP


6 ELF and VLF refer to extremely low frequency and very low frequency, respectively. This part of the electromagnetic spectrum is commonly said to range from 300 Hz to 30 kHz.

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