Subject: NanoFF-A (ILRS ID 2318518): Close-Proximity Notification with NanoFF-B (ILRS ID 2318517) From: Carabajal, Claudia C. (GSFC-61A.0)[SCIENCE SYSTEMS AND APPLICATIONS INC] Dear ILRS colleagues, Please see the message from the NanoFF mission colleagues regarding close-proximity of NanoFF-A and NanoFF-B, and tracking support of the mission. We appreciate your support. Regards, Claudia, ILRS CB Secretary ------------------------ Author: Debdeep Roychowdhury, TU Berlin Dear ILRS colleagues, We would like to inform you that NanoFF-A (NORAD ID 58810, ILRS ID 2318518) is currently predicted to approach NanoFF-B (NORAD ID 58755, ILRS ID 2318517) to within 1 km during 26–30 July 2026. This close approach is intentional and forms part of the mission’s formation-flying and proximity-operations objectives. As of 24 July 2026, the estimated relative separation is approximately 9 km and is decreasing by approximately 2.3 km per day. The mission team will continue monitoring the relative trajectory throughout the approach. 1. The mission will continue providing daily orbit predictions for NanoFF-A based on available onboard GNSS measurements. 2. Stations are kindly requested to continue attempting to track NanoFF-A whenever operationally convenient. 3. The mission currently has no access to GNSS measurements from NanoFF-B. Therefore, the latest Space-Track TLEs are the only available source for estimating NanoFF-B’s orbit. 4. No propulsive maneuvers are planned for either satellite during this interval. 5. Updated predictions and further notifications will be provided to the network as needed. Thank you very much for your continued support. Regards, Debdeep Roychowdhury -- Formation Flight Engineer Technische Universität Berlin Institut für Luft- und Raumfahrt | Institute of Aeronautics and Astronautics Fachgebiet Raumfahrttechnik (F6) | Chair of Space Technology (F6) Room 411, Marchstraße 12, 10587 Berlin Ph: +49 30 314-22345 | Fax: +49 30 314-21306 | LinkedIn: https://www.linkedin.com/in/debdeeprc/ | Email: roychowdhury@tu-berlin.de [cid:image001.png@01DB8E97.5E4A11C0] Claudia C. Carabajal Research Scientist SME HBG Geodesy & Geophysics Group Lead Secretary, ILRS Central Bureau Geodesy and Geophysics Laboratory, 61A NASA Goddard Space Flight Center 8800 Greenbelt Rd., Greenbelt, MD 20770 Claudia.C.Carabajal@nasa.gov