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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link="#0563C1" vlink="#954F72" style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal>Hi,<o:p></o:p></p><p class=MsoNormal>I submitted a paper, but I got a strange message so I will paste the paper into this email.<o:p></o:p></p><p class=MsoNormal>Farzana Khatri<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=Style1 align=center style='text-align:center'><span style='font-family:"Times New Roman",serif;font-style:normal'>Lunar Optical Communications<a style='mso-footnote-id:ftn1' href="#_ftn1" name="_ftnref1" title=""><span class=MsoFootnoteReference><span class=MsoFootnoteReference><span style='font-size:16.0pt;font-family:"Times New Roman",serif;mso-fareast-language:EN-US'>[1]</span></span></span></a><o:p></o:p></span></p><p class=Style1 align=center style='text-align:center'><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>Farzana I. Khatri and Bryan S. Robinson<o:p></o:p></span></p><p class=Style1 align=center style='text-align:center'><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>MIT Lincoln Laboratory, Lexington, MA, USA, </span><a href="mailto:farzana@ll.mit.edu"><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>farzana@ll.mit.edu</span></a><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'><o:p></o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'><o:p> </o:p></span></p><p class=Style1><u><span style='font-size:12.0pt;font-family:"Times New Roman",serif;font-style:normal'>Summary<o:p></o:p></span></u></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>Numerous studies have shown that NASA’s Deep Space Network (DSN) is woefully inadequate to support the current pace of space exploration [1]. Proposals are on the table for extensive infrastructure build-out using RF communications, which is ultimately bandwidth constrained. Optical communication offers unregulated, near-infinite bandwidth that can easily support the needs of humans at the Moon and beyond. Although not part of the proposed lunar network architecture, optical communication systems should be considered; these systems are operational now, quickly proliferating near earth space (e.g. StarLink), and offer very high bandwidths.<o:p></o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'><o:p> </o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>Lunar optical communication was first successfully demonstrated in 2013 by NASA’s Lunar Laser Communications Demonstration (LLCD) between the LADEE satellite orbiting the moon and three earth-based ground stations [2]. This demo heavily leveraged Commercial Off The Shelf (COTS) 1.5 </span><span style='font-size:11.0pt;font-family:Symbol;font-weight:normal;font-style:normal'>m</span><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>m optical components that are widely-available from telecom suppliers. The comm signal format used for LLCD was Pulse Position Modulation (PPM) with a ½-rate convolutional code and it operated error-free at up to 622 Mbps for the return link and 20 Mbps for the forward link. One of the ground stations, White Sands Test Facility (WSTF) in New Mexico, achieved a real-time comm link with better than 1 photon per bit efficiency. The physical link was also closed by ground stations with at JPL’s Table Mountain Facility (TMF) in California and ESA’s Optical Ground Station (OGS) at Tenerife. <o:p></o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'><o:p> </o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>After this demonstration, NASA and other non-U.S. space agencies embarked on deploying optical comm systems for near-earth. Several such systems, such as NASA’s Laser Communications Relay Demonstration (LCRD) [3] and ESA’s European Data Relay System (EDRS) [4], are operating today. Industry has also caught on and there are several near-earth optical comm systems in service, including SpaceX’s StarLink. Optical comm standards have also emerged, including some proposed by the Consultative Committee for Space Data Systems (CCSDS). CCSDS optical comm standards include a high photon efficiency standard using PPM [5] for Lunar and deep space applications, which has been successfully used for the Deep Space Optical Communications (DSOC) program [6]. <o:p></o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'><o:p> </o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>The upcoming Orion Artemis II Optical Communications (O2O) system will provide operational 1.5 </span><span style='font-size:11.0pt;font-family:Symbol;font-weight:normal;font-style:normal'>m</span><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>m optical comm using CCSDS-compatible PPM waveforms for the first crewed Artemis mission [7]. The system will provide up to 250 Mbps return link and 20 Mbps forward link from/to the Moon next year and will support live video during the mission as well as other applications. O2O will employ optical ground stations located at WSTF and TMF to form the Earth end of the link. Additional ground stations are being considered to support this mission and build out the optical ground station infrastructure.<o:p></o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'><o:p> </o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>Optical comm is technologically ready to make a huge impact on deep space comm networks, offering a way to aggregate local RF data over high bandwidth optical trunks and provide high data rate services for humans in deep space. Demonstrations are behind us and operational syste4ms are here now. The terrestrial telecom sector provides a pipeline of COTS components and sub-systems from which to build systems. Industry is now offering off-the-shelf, space-qualified optical comm terminals for near earth systems, some of which could be leveraged or modified to be compatible with longer range links. It is time that this technology be considered as a part of the Lunar and deep space comm architectures. <o:p></o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'><o:p> </o:p></span></p><p class=Style1><u><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-style:normal'>References<o:p></o:p></span></u></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>[1] “Audit of NASA’s Deep Space Network,” IG-23-016, Released July 12, 2023.<o:p></o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>[2] Boroson, D.M., Robinson, B.S., Murphy, D.V., Burianek, D.A., Khatri, F., Kovalik, J.M., Sodnik, Z. and Cornwell, D.M., 2014, March. Overview and results of the lunar laser communication demonstration. In Free-Space Laser Communication and Atmospheric Propagation XXVI (Vol. 8971, pp. 213-223). SPIE.<o:p></o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>[3] Israel, D.J., Edwards, B.L. and Staren, J.W., 2017, March. Laser Communications Relay Demonstration (LCRD) update and the path towards optical relay operations. In 2017 IEEE Aerospace Conference (pp. 1-6). IEEE.<o:p></o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>[4] Gregory, M., Heine, F., Brzoska, A., Oestreich, K., Mahn, R., Pimentel, P.M. and Zech, H., 2024, March. Status on laser communication activities at Tesat-Spacecom. In Free-Space Laser Communications XXXVI (Vol. 12877, p. 1287704). SPIE.<o:p></o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>[5] Optical Communications Physical Layer, CCSDS Blue Book, August 2019<o:p></o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>[6] Velasco, A.E., Allmaras, J., Kovalik, J., Garkanian, V., Douglas, B., Alerstam, E., Wright, M., Haque, S., Van Rhein, V., Macdonald, D. and Zhu, D., 2024, March. Deep space optical communications technology demonstration pre-launch validation and performance tests with the laser test evaluation station (LTES). In Free-Space Laser Communications XXXVI (Vol. 12877, pp. 44-58). SPIE.<o:p></o:p></span></p><p class=Style1><span style='font-size:11.0pt;font-family:"Times New Roman",serif;font-weight:normal;font-style:normal'>[7] Robinson, B.S., Khatri, F., Padula, M., Horowitz S., Bay, M., and King, J., Optical Communcations for Human Space Exploration – Status of Space Terminal Development for the Artemis II Crewed Mission to the Moon. In 2022 ICSOS Conference. IEEE.<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div><div style='mso-element:footnote-list'><br clear=all><hr align=left size=1 width="33%"><div style='mso-element:footnote' id=ftn1><p class=MsoFootnoteText style='line-height:10.0pt;mso-line-height-rule:exactly'><a style='mso-footnote-id:ftn1' href="#_ftnref1" name="_ftn1" title=""><span class=MsoFootnoteReference><span style='font-size:9.0pt;font-family:"Times New Roman",serif'><span class=MsoFootnoteReference><span style='font-size:9.0pt;font-family:"Times New Roman",serif;mso-fareast-language:JA'>[1]</span></span></span></span></a><span style='font-size:9.0pt;font-family:"Times New Roman",serif'> DISTRIBUTION STATEMENT A. Approved for public release. Distribution is unlimited. This material is based upon work supported by the National Aeronautics and Space Administration under Air Force Contract No. FA8702-15-D-0001. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Aeronautics and Space Administration.<o:p></o:p></span></p><p class=MsoFootnoteText style='line-height:10.0pt;mso-line-height-rule:exactly'><o:p> </o:p></p></div></div></body></html>