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Japan Aerospace Exploration Agency

Long-endurance UAS technology


March 25, 2015
Operating tests on a high-altitude, turbocharged engine for a high-altitude, long-endurance aircraft performed

In March 2015, JAXA performed operating tests on a high-altitude, turbocharged engine at its Chofu Aerospace Center.
While the most common type of aircraft engine is the gas turbine type, with its compact size and high levels of output, JAXA is exploring the idea of using reciprocating engines (diesel engines) in unmanned aircraft with long-endurance capabilities...[more]

In the event of a disaster, JAXA observes the afflicted area from space using its Advanced Land Observing Satellite "DAICHI" and makes that data available. Although DAICHI is capable of observing a very wide area at a time, there are issues with its observation frequency and readiness because any given point is visible only when the satellite is passing over it. On the other hand, manned aircraft can observe the situation on the ground in detail, but there are times when they cannot fly due to inclement weather.

Capable of staying in the high altitude without being affected by inclement weather, the high-altitude long-endurance unmanned aircraft system (UAS) enables continuous monitoring of a disaster situation that may be changing from moment to moment. And such long- endurance UASs are expected to contribute to the safety and security of society as they complement and reinforce the mission capabilities of satellites and manned aircraft.

High-altitude long-endurance technology

JAXA is also conducting research and development on high-efficiency airframe and engine technologies needed to implement 24/7 continuous missions all year round by rotation of two unmanned aircraft for observing Japan’s land areas and the nation’s exclusive economic zone (EEZ). JAXA carries out this R&D assuming that these technologies are used for such purposes as weather observation or maritime surveillance, in addition to disaster monitoring.

Airframe specifications
Wing span 46 m
Maximum weight 3.7 t
Payload Higher than 200 kg
Cruising altitude Higher than 16.5 km
Cruising speed Higher than 280 km/h
Endurance 72 hours

UAS operation technology

Currently, unmanned and manned aircraft do not share the same airspace, but with a view toward enabling more flexible operations for unmanned aircraft, international discussion is underway about integrating unmanned aircraft into existing air traffic systems. The International Civil Aviation Organization (ICAO) has a policy that calls for enacting a general framework of such flight rules by around 2018, and in response to this, ICAO member states may be expected to enact their own national legislations to suit the circumstances of their own countries.

For the technological and industrial development of the field of unmanned aircraft in Japan, it is important to accurately grasp international trends and, with respect to the technical challenges of standards that might be set in the future, in particular for specific challenges that Japan might face, to clearly describe, address and resolve such issues early on. In addition, with an international perspective, given the crowded airspace that surrounds Japan, being able to develop technologies that can guarantee the safety and efficiency of flights even in such a harsh environment will give Japan a highly competitive advantage internationally.

This research will clarify the technical problems to be solved for integrating unmanned aircraft into air traffic systems, while sharing that recognition with related organizations, and solve such technical problems through research and development initiatives that will build a foundation for achieving early mission utilization of unmanned aircraft systems.

Schematic diagram of operation