31 Dec 2020
Now orbiting is the Optical Data Relay Satellite – part of Japan’s new inter-satellite network.Japan Aerospace Exploration Agency (JAXA) and NEC recently announced the launch of LUCAS on board the Optical Data Relay Satellite, which was sent into or orbit last month from JAXA’s Tanegashima Space Center in Kagoshima, Japan, using an H-IIA rocket.
Photonics technology from diverse optical systems developer G&H is playing an important role in the communication system known as LUCAS (Laser Utilising Communication System), which employs hardware developed by NEC for JAXA.
The LUCAS system pushes the performance envelope in terms of data rates and latency, with the aim of offering near real-time availability of satellite data. G&H says the use of its “pioneering” system will show how laser communications can be a viable solution for future high-speed and scalable space communications.
Based on G&H’s undersea terrestrial communications capabilities as its starting point, the LUCAS system takes the company’s fiber optic systems and photonic technologies into space. Two types of laser communication systems have been developed: one for geostationary satellites and one for earth observation satellites deployed on a low Earth orbit (LEO).
LUCAS relies on power-efficient fibre optic and semiconductor laser technology operating at 1.55 µm. The laser communication equipment has been designed to withstand the challenging phase of launch, as well as long term radiation exposure whilst in orbit. LUCAS photonics technology deployed on-board the Optical Data Relay Satellite will be also used on JAXA’s future advanced earth observation satellites named DAICHI 3 (ALOS-3) and DAICHI 4 (ALOS-4).
Two two optical amplifiers
The LUCAS system has two optical amplifier systems, designed and manufactured by G&H, which create an all-optical bidirectional link between geosynchronous orbit and LEO satellites. A high-power amplifier system boosts the optical signal level before it goes out into space. A low-noise amplifier is used at the receiver side to amplify the very weak signals after having propagated in space across tens of thousands of kilometers.
Both optical amplifier systems are manufactured in G&H Torquay and include novel fiber-optics, space-grade laser electronics in addition to NEC-manufactured digital electronic boards for telemetry/tele-command.
Fully-hermetic, space-grade semiconductor laser modules manufactured in G&H Boston are also used in both the transmitter and amplifier systems. The amplifier flight models delivered passed system-level acceptance testing, including mechanical shock, vibration and operation in vacuum.
Stratos Kehayas, G&H Chief Technology Officer, commented, “The amplifier system launched is packed with G&H technology. A testament to the power of vertical integration, we used our unique component base in Torquay, UK and Boston, USA to develop novel and high-performing space photonic systems for satellite laser communications.
“To the best of our knowledge this is the first time 1.55 µm optical fiber amplifiers have been deployed in the GEO orbit. We also created the necessary space-grade system manufacturing and assembly procedures and applied these in world-leading, purpose-built cleanroom facilities in Torquay, UK to manufacture these amplifiers.”