Space Domain Awareness

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Space Domain Awareness

Space Domain Awareness

@shell_jim

Space surveillance, SSA/SDA, orbital debris expert. Retired USAF with 30+ years of space experience. Physics (M.S.) and Imaging Science (PhD). USAFA '92.

Joined Şubat 2012
261 Following1.9K Followers
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Space Domain Awareness
Space Domain Awareness@shell_jim·
3/n This animated plot illustrates the evolution of the orbit plane of the debris field, with the color coded to the area/mass of the objects. Only objects with an accuracy < 1000 km at epoch are shown (677 as of 2025-02-24).
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Dr Marco Langbroek 🇬🇱 🇩🇰
Dr Marco Langbroek 🇬🇱 🇩🇰@Marco_Langbroek·
AROUND THE MOON: #Artemis/Orion is rounding the moon and about half an hour away from being farthest from the Earth. It will loose radio contact for about 40 minutes around that moment.
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Merkouris SV2HWM
Merkouris SV2HWM@SV2HWM·
Another 🛰️ broadcasting Beethoven's "Ode to Joy". It appears to have been deployed with SpaceX Transporter-16 Rideshare. Tlm was successfully demodulated, but apart from some frames containing the manufacturer's name @EnduroSat, nothing else was useful for identifying the bird.
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Okuyama Lab
Okuyama Lab@LabOkuyama·
[Ten-Koh2 Has Been Deployed!!] We are pleased to report that the 6U CubeSat “Ten-Koh2,” developed by our lab, has been deployed from the H-SSOD on HTV-X1 🛰️ Further updates on the satellite status will be posted on this X account and our lab website 📢 #TenKoh2 #HTVX #CubeSat
Okuyama Lab tweet media
Okuyama Lab@LabOkuyama

【てんこう2放出のお知らせ】 先程、弊研究室で開発された6U衛星「てんこう2」がHTV-X1のH-SSODより無事放出されたことをご報告いたします🛰️ 本衛星の状態等については、本Xアカウント及び弊研究室HPにて随時お知らせいたします✨ #TenKoh2 #てんこう2 #HTVX #CubeSat #日大理工

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HEO
HEO@heospace·
In-space view of the largest commercial communications array antenna in low-Earth orbit, fully unfolded. Congrats on the successful launch of BlueBird 6 @AST_SpaceMobile! Image taken from 106 km away at a 16 cm/px resolution.
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Dr. John Barentine FRAS
Dr. John Barentine FRAS@JohnBarentine·
I’m told by those in a position to know that some (currently small) fraction of these are satellites and/or space debris.
U.S. National Science Foundation@NSF

NSF-DOE @VRubinObs has released its first alerts documenting astronomical events spotted by the observatory. The alerts call scientists' attention to new asteroids, exploding stars and other changes in the night sky. 🌌 bit.ly/4aCSANT

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Mickey
Mickey@mickeywzx·
Correction! By newly published TLE, these are Russian GSO mission on the same day, deployed weather sat Elektro-L No.5 with secondary payload Iran-DBS. The venting and debris are from Blok-DM-03 upper stage.
Mickey@mickeywzx

3hrs time lapse for USSF-87 Centaur V upper stage post separation action on Feb 12th, including fuel dumping and possible disposal maneuver. They are all inserted into a sub GEO orbit. In the end, Centaur V appears to drift eastward faster than the two spotted payloads.

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Paul Montagne
Paul Montagne@AstroPolo_Space·
Hello @planet4589, do we have a more precise estimation than "from few years to 4 decades" about the inaugural Ariane 6' second stage reentry due to failed deorbit burn please ? 🙂
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Space Domain Awareness
Space Domain Awareness@shell_jim·
@astro_Pettit @Starlink These images are fantastic. Appreciate the continued posting! The Starlink flashes are not from the solar arrays, but rather the nadir-facing deck which has a mirrored surface. This reduces their brightness for earth-based viewing (attempting to be dark skies compliant).
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Don Pettit
Don Pettit@astro_Pettit·
SpaceX @Starlink satellites flashing like shooting stars with time exposure. Dozens could be seen in rapid succession near our orbital dawn and dusk, when their solar panels reflected sunlight at the proper angles!
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Space Domain Awareness
Space Domain Awareness@shell_jim·
*** Yaogan-50 - China's First Retrograde LEO Satellite *** On 13 Jan 2026 China launched Yaogan-50-01, its first LEO satellite in a highly retrograde orbit (ref graphic). While the payload is unknown, a probable contender is a synthetic aperture radar (SAR) system as the higher velocity relative to the earth's surface also serves to increase the spatial resolution(?). Such a high inclination also provides improved revisit times time for lower latitude locations--such as the South China Sea. (Orbit data from U.S. Space Forces – Space (S4S) via space-track.org, used with permission per ODR 24-002-4).
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Stephen Clark
Stephen Clark@StephenClark1·
Another clean sweep for SpaceX with these NSSL Phase 3 Lane 1 awards.
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Space Domain Awareness
Space Domain Awareness@shell_jim·
Starlink's first space debris event occurred on December 17, 2025. A remarkable response by commercial SSA companies--but a misstep by not acknowledging PRC crewed flight concerns which will only fuel Chinese rhetoric. Event summary -> spacedomain.substack.com/p/starlinks-fi…
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Space Domain Awareness
Space Domain Awareness@shell_jim·
@planet4589 As always - very much appreciate your annual summary and ongoing GCAT data curation! Happy new year.
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CNSPACE
CNSPACE@CNSpaceflight·
China's representative criticized the 'reckless expansion' of LEO constellations, citing specific security threats. Claims Starlink forced the China Space Station into emergency avoidance maneuvers twice. Accuses the network of ignoring local laws to activate service in unauthorized zones. Claims the network being used as a tool for interfering in internal affairs and aiding separatist/terrorist groups and fraud groups in the Sahel and SE Asia. China is urging relevant countries to strictly abide by their obligations under the Outer Space Treaty to regulate their domestic commercial space activities.
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Jonathan McDowell
Jonathan McDowell@planet4589·
Several days since apogee/perigee for the 2025-311 objects appeared on Space-Track catalog page, but still no GP data (TLEs). I don't understand this new @S4S_SDA habit of not releasing the TLEs till long afer the peri/apo are available, it's happened several times lately
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Discover

@s2a_systems @Marco_Langbroek @SV2HWM @EnduroSat @grok @FutureJurvetson @SpaceX @K2SpaceCo