LUCAS: The second-generation GEO satellite-based space data-relay system using optical link

Research and development of key technologies for cislunar optical communication systems in Japan

“…Actually, ground-to-satellite optical link has still been studied worldwide [7] [8]. In contrast, since inter-satellite optical links utilizing optical data relay satellite has practically been operated such as European Data Relay System (EDRS) [9], Laser Communications Relay Demonstration (LCRD) [10] and Laser Utilizing Communication System (LUCAS) [11], we assume that (1) is currently desirable for cislunar optical communication system. Meanwhile, regarding (3) and ( 4), since HPE method utilizing Pulse Position Modulation (PPM) and Super-conducting Single Photon Detector (SSPD) can realize ultra-high receiver sensitivity, this method is also potential for cislunar optical communication system [12][13].…”

High power wavelength division multiplexing (HP-WDM) for high-speed space optical communication

“…Free-space optical communication, enabling us to achieve high-speed data transmission superior to conventional radio frequency (RF) communications, has the potential to fulfill the expanding communication needs as we continue our space activities. For example, Earth observation satellites require a wideband optical channel for data transfer along with an evolution of precise image sensors [1] . Moreover, free-space optical communication is expected to increase communication distances, which is essential for cislunar space networks and deep space exploration missions [2] .…”

Characterization of Mega-Constellation Links for LEO Missions With Applications to EO and ISS Use Cases

“…In recent years, data relay constellations (typically in GEO, but some in LEO, too) [12], [13] have been envisioned to address such a need through radiofrequency (RF) and optical interfaces, being proposed by academia [14] and industry [15]- [17] alike. Furthermore, recent developments in optical terminal capabilities promise a great increase in capacity and efficiency so far unachievable by most space users, including remote sensing and Earth observation satellites.…”