Elektra Two Solar

solar-powered Aircraft

Elektra Two Solar is the standard aircraft of the Elektra Two family for science and surveillance purposes in high altitudes

Application

The aircraft is equipped with two seats. The solar-electric aircraft is a highendurance aircraft, which has been designed to endure long distances as well as high altitudes.

Elektra Two Solar can be used as a platform for creating 3D-mapping and can be used to take various measurements, such as air pollution at high altitude. It can also fulfill other data acquisition and surveillance purposes.

Description

The two-seat tandem solar aircraft can fly only using the energy from the sun. At low altitude the aircraft can fly with only about 2 kW power. The maximum power provided from the sun is about 5 kW. In this case, very long-range and high-altitude flights are possible. The complete redundant power unit system is the best guarantee for a safe flight.

The main characteristic of the aircraft is the combination of high-end aerodynamics (glide ratio over 40) and the fact that it is as light as it can possibly be. The complete structure is built according to the latest state-ofthe- art carbon technology. Optionally, the aircraft can be equipped with a completely autonomous flight system including automatic takeoff and landing. For this reason the aircraft can be classified in the OPS class. The aircraft can fly with two passengers but also completely autonomously (UAS).

The wings and fuselage skins are made of carbon (TeXteeme) + 2/3mm Kevlar honeycomb. The wings spar cap is made of carbon pultruded bonded UD strips with 70% fiber concentration and 2000 MPA tensile stress and the main landing gear strut is made of carbon pultruded bonded UD strips.

Technical specs

Elektra TWO Solar

Available as “Unmanned Aircraft System”(UAS version) or “Optionally Piloted System” (OPS version).
Among other things, the aircraft serves as a platform for customer-specific payloads.

SPECS
OPS
(Optionally Piloted System)
UAS
(Unmanned Aircraft System)
Seats
2
no
Electric Motor
23 kW
23 kW
Propeller speed for cruise
1.250 rpm
1.250 rpm
Wingspan
24.8 m
24.8 m
Wing Area
27 m²
27 m²
Solar cells
23.5 m²
26.5 m²
Maximum weight
450 kg
400 kg
Tare w/o battery
250 kg
160 kg
Battery weight
120 kg
120kg
Maximum payload
200 kg
120 kg
Maximum flight duration*
almost unlimited
almost unlimited
Range*
almost unlimited
almost unlimited
Cruising speed
70 km/h
70 km/h
Power needed for horizontal flight
2.2 kW
1.6 kW
Max. power provided by solar cells
> 5 kW (depending on altitude)
> 5 kW (depending on altitude)
Wing aspect ratio
23
23
Maximum altitude
20 km
20 km
Max. glide ratio
> 1:40
> 1:40
Certification
LFT-UL 2003 Germany
according to country-specific regulations
*Depending on wind conditions

Optionally

PILOTED

System

Designed for optionally piloted stratospheric missions up to 70.000 ft. altitude.

Elektra Two Solar OPS (Optionally Piloted System) was designed to be used as unmanned electric-solar airplane for stratospheric missions at 70.000 ft. altitude. In direct sunlight it is possible to fly day and night, whereby of course the payload is limited. The aircraft will be delivered in optionally piloted version with the cockpit for one pilot. The autopilot can be activated and deactivated by the pilot. Having pilot inside the aircraft, the autonomous operations without special permissions for UAVs are possible.

The power is provided by combined solar and rechargeable batteries. The electrical energy is summarized at a junction point between the engine and the battery. As long as the energy consumption of the engine is higher as the energy provided by the solar cells the battery has to provide the missing additional energy. If the engine is using less energy as the solar cells provide, the batteries where charged until they are fully charged.

The electrical power unit has double redundancy and is composed of two systems working in parallel. Each of the two systems is composed of one electrical motor, motor controller and battery with battery management system. Two electrical motors are mounted on one shaft, forming a double-redundant engine unit.
The aircraft was developed for fully autonomous navigation. The control can be done either from the cockpit and / or from the ground station.

Unmanned

Aircraft System

Unmanned Aircraft System for stratospheric flight up to 70.000 ft. altitude for day-night missions like border control.

The unmanned version can be flown in countries where unmanned flights are allowed.
Elektra Two Solar UAS was designed to be used as unmanned electric-solar airplane for stratospheric missions up to 70.000 ft. altitude.

Takeoff and landing by using a variety of sensors, fly back to the point of takeoff, GPS waypoint navigation and automatic roll and yaw control while moving horizontally are only a few characteristics which distinguish this aircraft. In combination with solar cells and state-of-the-art battery technology, it is practically possible to fly day and night. The electrical power unit has double redundancy and is composed of two systems working in parallel. Each of the two systems consists of a electrical motor, motor controller and battery with battery management system. Two electrical motors are mounted on one shaft, forming a double-redundant engine unit. The whole control of the plane can also be done from a ground station.
The use of Elektra Two Solar UAS is rapidly expanding in the recent past to commercial, scientific and other applications, such as policing, peacekeeping, surveillance and aerial photography. With the aid of a laser communication system or a radio system, data can be transmitted in real time over several 100 km.