NASA has broken new ground by adding UAVs to its fleet of Earth observation platforms


On 5 March, a large container ship is due to set sail from the West Coast of the USA bound for the Hawaiian Islands with an unusual cargo. On board, carefully packed away in sections, will be the enormous 75m- (250ft) span Helios Prototype unmanned air vehicle (UAV), which will be put together on the island of Kuaui in May before an attempt is made to fly it to a record altitude of 100,000ft (30,500m).

Helios Prototype, built by AeroVironment of California, is the latest variant of a solar-powered UAV family which has been nurtured under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. This kicked off in 1993 with the aim of developing aeronautical technologies for a suite of long-endurance remotely piloted vehicles or UAVs that could be used in upper atmospheric science missions to collect, identify and monitor environmental data to assess global change. As a secondary target, ERAST aircraft were also seen as potential "atmospheric satellites" for future telecommunications systems.

Helios Prototype is one of the fruits of the ERAST effort which is provisionally scheduled to end next year. The attempt to reach 100,000ft is a key target which will help convince the sceptics that the concept of a high-altitude surrogate satellite is real and very much within reach.

To continue the process and convert the ERAST UAV family and other UAVs into working systems, NASA's Office of Earth Science in Washington DC has opened a competition, the winners of which will pioneer use of UAVs for actual operational science missions.

John Hicks, ERAST project manager at NASA Dryden Flight Research Center, California, heralds the move as "an historical first for NASA Earth Sciences in adding UAVs to its operational class of Earth observation platforms that have included satellites, manned aircraft and balloons. This is a real catalyst to the technologies and operational capabilities we are developing in ERAST."

NASA has shortlisted 11 potential proposed demonstration missions, eight of which are derived from the ERAST project. The General Atomics Altus provides the basis for five of these proposed studies into hurricane monitoring, cirrus cloud research, thunderstorm studies and two atmospheric chemistry studies.

Three are based on Pathfinder, a progenitor of Helios, and include a disaster management study, a coffee harvest optimisation study and an atmospheric water and climate change study. Other non-ERAST UAVs included in the proposals are the Northrop Grumman Global Hawk, which has been put forward as the platform for an atmospheric chemistry study; an agricultural study of vineyards using the Vindicator; and a hurricane and storm study using the Aerosonde aircraft.

NASA hoped to make its final downselect to as many as three finalists in March, but the process of submitting detailed proposals has taken longer than expected and a final decision is now not due until April at the earliest says the agency. The focus of the programme, however remains tight, and is expected to lead to the first missions taking flight next year.

Unlike some other technology-based NASA activities which are in search of applications, Hicks believes the sheer utility of UAVs and the range of potential applications turns this on its head: "In NASA we're often pushing technology and looking for applications. This time it's the other way around - there are more than we can handle," he says.

Apart from the science-based missions already slated for UAVs under the NASA effort, several other applications "from the mundane to the exotic" are being considered, says Hicks. "Disaster management is a big one. We have people looking at using them to help co-ordinate quick response to earthquakes, volcanic eruptions, tornados and particularly forest fires. The forest fire application would include things like tracking the flame front in real time and deploying ground crews where they will make the biggest impact."

Another application closer than most to UAV use is resource monitoring, particularly mapping. The state of California, for example, is actively seeking a low-cost, airborne platform to perform a detailed mapping project of the state. The project will involve covering the entire state in north-to-south 15km- (10 mile) wide photographic swathes which will later provide information for city planning, forestry management and other aspects of resource management.

Helios Prototype flight tests, which are scheduled to be completed by late July, are also expected to provide the foundation for other non-ERAST applications such as AeroVironment's proposed Skytower programme, an airborne telecommunications relay project. Given the level of activity surrounding NASA's Office of Earth Sciences and ERAST projects, it seems the age of UAV utility is truly about to begin.

Source: Flight International