[SLS-OPT] Minutes of July 7 teleconference

Wed Jul 8 16:03:45 EDT 2026

Dear Jon, dear all,

I am sorry to not have been available last tuesday (due to the launch of a cubesat in which I was deeply involved in).

Please let me kindly report about the optical communications aspects addressed by last SFCG meeting, since an action item was placed on me on this issue for Tuesday's OPT WG intersessional meeting:

  1.  SFCG Liaison from CCSDS (focused on optical coms in this reporting):

  *   Dennis presented to SFCG the main body of the attached document, related to RF communications and standards issues. I presented the attachment in annex of this document (also attached separately), reporting on progress of CCSDS on optical communication standards.
  *   After this presentation, SFCG concluded that:
     *   It should be interesting to get from member agencies inputs informing SFCG about their project(s) in space optical communications.
     *   The SFCG resolution 20-2R3 on optical communication (slide number 3) may be revised at next SFCG meeting

  1.  Other issues on optical communications discussed during this SFCG meeting;

During another discussion at SFCG (another day), NASA presented the need for new lunar frequency bands for new applications, as described in the attached NASA contribution SF45-57D. NASA suggested the possibility of a new ITU agenda item to study allocation of new lunar frequency bands (with an allocation different from Space Research Service as studied by the current "lunar" ITU agenda item: A.I. 1.15). No agency contested the need for these new services; CNES recognized (like NASA) the need for these new services.

CNES however highlighted that any new wide lunar RF band which would be allocated by ITU in all the lunar region might be to the detriment of Radio Astronomy Service (RAS) in the Shielded Zone of the Moon (SZM). With the goal to minimize the impact on RAS in the SZM, CNES suggested, before freezing a new ITU agenda item, to well study if a part of the Space Research Service (SRS) lunar bands to be allocated next year by ITU (close to the "lunar freqs" of SFCG REC 32-2R7) could not be partly used for these new services, and also to well study if optical communications could deliver (or not) at least a part of the targeted services. CNES (I) added that optical communications look well suited to several cases in the lunar region, like at least:

  *   Point to point links between habitats and/or shelters (of a Moon base for instance).
  *   Communications between the lunar surface and lunar orbiters
  *   Communication between lunar orbiters and a GEO relay
  *   ...
A remark was done about a possible not-negligeable impact of the lunar dust on the optical links near the lunar surface*.

But for the moment, SFCG member agencies are invited to work and comment on the needs for new lunar communication high data rate services, regardless the related bands being RF or optical.

Do not hesitate, Dennis, to add anything on points 1) or 2), if needed.

Have a nice day; VBR

Jean-Luc

* I think that informational inputs to CCSDS and/or SFCG meetings on the issue of lunar optical communications in general (which project, which CCSDS standard, ...) and also about the impact of lunar dust on the presented optical lunar links could be very interesting in that context. I also found a paper on the impact of lunar dust on optical links:

https://arxiv.org/html/2401.17942v3

It seems that as long as the link is more than one meter above the surface, the impact of lunar dust is manageable during the lunar day (during the lunar night, the maximum data rate is higher). Anyway, the communication terminals should not be too close from the surface for the links (RF or optical) to better avoid obstacles. Another remark for RF lunar links: when RAS protection thresholds in the SZM will be established, this could mean that maximum RF data rates could be higher in the near side region compared to the SZM region. Therefore, there is a possibility that both RF and optical links could have a maximum data rate higher on one lunar hemisphere compared to the other.

De : SLS-OPT sls-opt-bounces at mailman.ccsds.org<mailto:sls-opt-bounces at mailman.ccsds.org> De la part de Hamkins, Jon (US 3611) via SLS-OPT
Envoyé : mardi 7 juillet 2026 16:54
À : sls-opt at mailman.ccsds.org
Objet : [SLS-OPT] Minutes of July 7 teleconference

Hello,

Attached are the minutes of today's meeting. If you made a presentation, please remember to put it into the meeting folder in CWE. I created folders for today's meeting, and also one for the August meeting.

Geraldine, please let us know when the time series are in place. When you are ready you can send a message to the mailing list about where they are. Thanks.

I've also sent out an invitation for the August 25 meeting. It includes an agenda. If you want anything added/adjusted to the agenda, let me know.

     ----Jon

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.ccsds.org/pipermail/sls-opt/attachments/20260708/b14b35dd/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: SF45-64I attachement CCSDS progress in optical communication standards.pptx
Type: application/vnd.openxmlformats-officedocument.presentationml.presentation
Size: 5340385 bytes
Desc: SF45-64I attachement CCSDS progress in optical communication standards.pptx
URL: <http://mailman.ccsds.org/pipermail/sls-opt/attachments/20260708/b14b35dd/attachment-0002.pptx>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: SF45-64I CCSDS Liaison Statement to SFCG - V2.docx
Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
Size: 5389799 bytes
Desc: SF45-64I CCSDS Liaison Statement to SFCG - V2.docx
URL: <http://mailman.ccsds.org/pipermail/sls-opt/attachments/20260708/b14b35dd/attachment-0001.docx>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: SF45-57D NASA SFCG Inputs to ITU-R Future PDNR on Lunar Spectrum Needs (NASA).pptx
Type: application/vnd.openxmlformats-officedocument.presentationml.presentation
Size: 1080926 bytes
Desc: SF45-57D NASA SFCG Inputs to ITU-R Future PDNR on Lunar Spectrum Needs (NASA).pptx
URL: <http://mailman.ccsds.org/pipermail/sls-opt/attachments/20260708/b14b35dd/attachment-0003.pptx>