Results of the Optical Link Study Group

Abstract

The Inter-agency Operations Advisory Group (IOAG) established an Optical Link Study Group (OLSG) at its meeting in 2010 to investigate the business case for cross support of spacecraft that may utilize optical communications in the future. This paper addresses the work that was done by the seven international space agency members of the OLSG. It was found that since clouds make optical communications through the Earth atmosphere impossible, in order to maintain high availability of spacecraft communications it is necessary to have weather de-coupling of individual ground stations. Other issues such as aircraft intrusion, atmospheric turbulence, and atmospheric aerosol considerations are also important factors in choosing which optical ground station to use for spacecraft data downlinking. In order to maintain high levels of optical communication capability it was found that numerous ground stations are required. Based on specific mission scenarios from low earth orbit to deep space, and Earth relay inter-satellite links, the feasibility of optical space communication solutions will be discussed and critically assessed for their maturity of being considered for implementation. Due to the cost of establishing optical communication ground stations with appropriate weather diversity around the globe, or to deploy earth relay satellites, the OLSG concluded that cross support based on interoperable solutions implementing international standards is an essential requirement to advancing this new method of spacecraft communication. The OLSG also identified the need to develop a detailed standardisation roadmap in order to enable an efficient standardisation process.

NASA’s current activities in free space optical communications

“…The OLSG completed its Final Report in 2012, with an official addendum with more details added in 2013, stating that a business case had been found for optical communication cross support. [10] Having a worldwide standard for optical communications would enable cross support by other space agencies, thereby increasing the number of communication paths available to a given mission. The OLSG recommended that the IOAG ask CCSDS to form an Optical Communications Working Group to develop an international standard for optical communications to facilitate the worldwide deployment of this technology.…”