## 2 UAS Platform Types and Characteristics
### Characteristics and Examples of UAS Categories
#### 2.2.5. HALE UAS
The GRIP deployment was 15 August-30 September 2010 with the Global Hawk operating from NASA Dryden Flight Research Facility, CA, USA, flying to the Atlantic to measure and track hurricane systems while other sampling aircraft (manned) flew shorter mission legs from Florida and Texas. The 2011 Winter Storms and Pacific Atmospheric Rivers, or WISPAR campaigns, were a series of observations led by the National Oceanic and Atmospheric Administration (NOAA) during long-duration NASA Global Hawk flights over the Pacific Ocean that explored atmospheric rivers and Arctic weather and collected targeted observations designed to improve operational weather forecasts. The missions were run from February to March 2011. The airborne campaign focused on improving scientists' understanding of how atmospheric rivers form and behave and evaluating the operational use of unmanned, high-altitude aircraft for investigating these phenomena. The research was also designed to assist NOAA in conducting potential offshore monitoring of atmospheric rivers to aid in future weather predictions. Figure 11: The NASA/NOAA Global Hawk HALE UAS. Image courtesy NASA. Starting in summer 2012, the Hurricane and Severe Storm Sentinel (HS3) will be a five-year mission specifically targeted to investigate the processes that underlie hurricane formation and intensity change in the Atlantic Ocean basin. HS3 will utilize two Global Hawks, one with an instrument suite geared toward measurement of the environment and the other with instruments suited to inner-core structure and processes. Missions planned for 2013 and 2014 include the Airborne Tropical Tropopause Experiment and will employ the NASA Global Hawk to study the stratospheric humidity, ozone concentrations, and water vapor climate to improve our assessment of changing climate and feedbacks. The missions are planned for operations in Guam and Darwin, Australia. Extreme long-duration platforms, like the Qinetiq Zephyr (Figure 12), are built of carbon-fiber composites, with lithium sulfur batteries taking energy from the solar cells that compose the upper surface of the wing. These platforms will see more civilian utility in the near future, supporting regionalized, long-duration observations. The Zephyr already holds the UAS endurance record (set in July 2010) for its sustained flight of 336 h, 22 min (two weeks). Currently, the aircraft has a service ceiling of \(\sim\)21,000 m and a payload of 2.5 kg. It is envisioned that the Zephyr will provide 3-month on-station capabilities. HALE UAS platforms are primarily valuable for strategic observation of large-scale (global/continental) phenomena where other platforms do not have the flight characteristics to support extensive mission operations. Platforms like the Global Hawk and the Zephyr (and other, similar platforms currently in development) will see increased use in atmospheric studies, and there are indications that HALE platforms in the next few years could provide near-continuous coverage of the  
Figure 12: The Qinetiq Zephyr HALE UAS. Image courtesy QuinetiQ Group, PLC, Farnborough, Hampshire, England. Earth's surface through long-endurance flights lasting from one month to up to five years. These sub-orbital observations would provide a significant cost savings over satellite platforms, allowing a HALE UAS to be repeatedly returned to earth for sensor modifications/upgrades and the addition of new payloads. This is not feasible with current, costly orbital assets.