Not a good story. Over the past year, China continues to abandon numerous upper stages in long-lived low earth orbit,* counter to best practices for the long term sustainment of space. I initially sounded the alarm on this issue in April 2025, and further highlighted the issue in an August 2025 article and...the update is that things only continue to get worse. For those not familiar, the total orbital debris mass is a key variable for the long term sustainment of space. There is broad agreement that abandoning rocket body upper stages in long-lived orbits is NOT a best practice. In fact, all the major space-faring nations have acknowledged this (e.g., IADC signatories). However, as China's "mega constellations" launch rate increases, so does the number of abandoned rocket bodies in long-lived high LEO orbits. Russia and the US dominate the number of rocket bodies remaining in such long-lived orbits, rooted in historical practices from decades ago with minimal orbital debris concerns (graphic, bottom panel). HOWEVER, China's upper stages are estimated to have much higher masses on average. Although the US has almost double such objects, China's total mass of such objects is 252 metric tons and increasingly rapidly vs the US total of 57 metric tons (and holding steady). It's acknowledged there are some uncertainties in PRC upper stage dry mass values (Graphic, top panel). No matter, things are not going well. * "Long-lived LEO" is defined here as having a min perigee height of 600 km and an orbit height less than 2000 km (to preclude HEO rocket bodies) ** Object mass estimate use @planet4589 's dry mass from the GCAT *** Orbit data from U.S. Space Forces – Space (S4S) via space-track.org, used with permission per ODR 24-002-4.

1/n Thank you @heospace for facilitating "Positive ID" of a Chinese payload (OBJECT A - 57424) from this 2023 PRC launch with multiple payloads (launch 2023-104). x.com/heospace/status/205724…

2/n It's constructive to examine the optical signatures of all PRC objects associated with this launch (2023-104), simply identified as Objects A-F in the US public catalog (space-track.org). A total of 6 objects have been cataloged from the launch; however, none of the objects are identified by name (SATNOs 57424-47529). Given HEO's NEI image of an object from the launch, it's constructive to examine the optical signatures of all objects associated with the launch. "OBJECT A" has a median optical cross section (OCS) of 13.9 dBsm, or ~24 m^2 (derived via a diffuse sphere model with albedo of 0.2). OBJECT A's optical cross section (OCS) is significantly larger than all of the objects from this launch for which optical signature data are available* (ref graphic). * Optical signature data is open source courtesy of the Russian MMT system.

Military Space History #18: 1976: @NRO_gov Satellite Survivability Mandatory reading for all @USSpaceForce Guardians, and my reminder that space was "born contested!" It's been a while since my last "Military Space History" installment. This highlight comes courtesy of the NRO's annual "Sunshine Week" declassification and public release of historical documents, with this trove largely consisting of documents hitting the 50 year declassification milestone. 1/2

On July 7, 1976, President Ford issued National Security Decision Memorandum 333 (NSDM 333) "Enhance Survivability of Critical U.S. Military and Intelligence Space Systems." The growing dependence of the U.S. on satellite reconnaissance coupled with the growing Soviet ASAT threat prompted NSDM 333. NSDM called for the SecDef and DCI to balance the level of survivability of satellite systems commensurate with their mission importance. The NRO's response was quantified via the NRO's "Survivability Enhancement Action Plan," with the study completed in October 1976. The declassified study is a treasure of information regarding the assessed Soviet counterspace threats at the time, and an assortment of options to "Protect and Defend" (today's vernacular) against these threats. The full document in it's entirety may be downloaded here: nro.gov/Portals/135/document… (nro.gov URL) 2/2 #SpaceDomainAwareness #MilitarySpaceHistory #AlwaysContested #OurGrandparentsHaveBeenThereAndDoneThat! #ASAT

Questions on China's new Feng Yun 4C (FY-4C) meteorological satellite launched on 2025-12-26. Looking for answers.... A post by @SegerYU indicates robotic arms? I have not seen this elsewhere? Presumably this may facilitate on-orbit servicing? (Also wondering now if there is a designation for this SAST bus)? x.com/SegerYU/status/2004250…

OK, seems I should have just read @PhazzeeYeehaw's article on the launch first! So, the robotic arms have electric thrusters on the end of them, which apparently facilitates an ability to dial in a thrust direction without having to change the satellite attitude-which is honestly pretty innovative. x.com/PhazzeeYeehaw/status/2…