Share this page!

Enter URL or ID to Unroll

You can paste full URL like: https://x.com/threadreaderapp/status/1644127596119195649
or just the ID like: 1644127596119195649

How to get URL link on X (Twitter) App

  1. On the Twitter thread, click on or icon on the bottom
  2. Click again on or Share Via icon
  3. Click on Copy Link to Tweet
  4. Paste it above and click "Unroll Thread"!
  5. More info at Twitter Help
Dr Marco Langbroek Profile picture
Dr Marco Langbroek
@Marco_Langbroek
Lecturer optical Space Situational Awareness @AETUDelft. Spy sats, missiles, meteorites, asteroids. Asteroid (183294). Former archaeologist. Opinions my own
Aviva Gabriel Profile picture 1 subscribed
Nov 18, 2023 • 7 tweets • 2 min read
So, I did some simulations with GMAT.
Assumptions:
- For totally arbitrary drag area of 1 m^2;
- Near-orbital speed at disintegration;
- disintegration at 148 km;
labels are mass in kg of fragment.
@planet4589 @DJSnM @Ian_Benecken Image 2/x
 additional info: no mass loss due to ablation upon reentry (this is important: if they do loose mass 9and they will), they come down earlier than in the map)
Oct 25, 2023 • 8 tweets • 4 min read
1/x
 The very successful @AETUDelft-built 3U cubesat Delfi-C3, launched 15 yrs ago, is near the end of its life. It will probably reenter into the atmosphere next month.
Yesterday evening, I managed to image it with my tracking camera from Leiden, the Netherlands: Image 2/x
 Here is the video footage (it is very faint, being a 3U cubesat, i.e. 10 x 10 x 30 cm large). Footage was shot at 25 fps with a WATEC 902H2 Supreme and Samyang 2.0/135 mm lens.
Feb 18, 2023 • 9 tweets • 4 min read
Approximate trajectory flown by the #ICBM that #NorthKorea tested today. A highly lofted trajectory.
(reconstruction based on Japanese DoD info).

When launched on a 'normal', non-lofted trajectory, the range would be 18000+ km, i.e. capable of reaching any place on Earth Trajectory is based on rough information on apogee, range, and map with approximate impact point provided by Japanese DoD here:
mod.go.jp/j/press/news/2…
Aug 1, 2022 • 6 tweets • 2 min read
Rumour has it that thisd might be another inspector satellite.
The orbital plane of USA 326 passes over Plesetsk at 20:25 UT USA 326 (2022-009A) was launched on February 2 this year and is believed to be a new generation of electro-optical reconnaissance satellite:
sattrackcam.blogspot.com/2022/02/the-up…
It is in a 97.4 deg inclined, 518 x 488 km orbit.
Feb 26, 2022 • 8 tweets • 4 min read
1/x
 Navigational Warnings have appeared that suggest a #test launch of a #Minuteman #ICBM from Vandenberg on March 3 - 4.

(I suspect 1 or 2 more NavWarnings to appear for areas around Kwajalein, based on previous tests)
@nukestrat @mhanham @wslafoy @ArmsControlWonk ImageImage 2/x
 To be clear (as such suggestions always arrise):
This has *nothing* to do with the Ukraine crisis. Tests like these are scheduled months in advance.
They are regular tests to ascertain the readiness and training of missile crews.
Oct 17, 2021 • 26 tweets • 5 min read
1/x
 (lange) draad:
Het gaat véél verder dan een "hypersonische raket": de Fin. Times claimt dat de Chinese test een test voor FOBS betrof...

FOBS staat voor "Fractional Orbital Bormbardment System". FOBS lanceer je niet op een ballistisch traject zoals een normale ICBM, (cont.) 2/x
 ...maar worden echt in een baan om de aarde gebracht, zoals een satelliet. Waarna op een gegeven moment met een deorbit burn door een retroraket, de lading weer omlaag wordt gebracht, boven het doelwit.
Welnu: waarom zou je dit zo doen in plaats van een normale ICBM lanceren?
Oct 16, 2021 • 6 tweets • 3 min read
1/x
 It is with great pleasure that I can announce that the Working Group on Small Body Nomenclature of @IAU_org has decided that asteroid (563318) will henceforth be named:

(563318) ten Kate

After the Dutch @UniUtrecht astrobiologist/planetary scientist Dr @ingeloes ten Kate 2/x
 The naming citation for (563318) ten Kate was published yesterday in IAU-WGSBN Bulletin vol 1. nr 10, p 7:
wgsbn-iau.org/files/Bulletin…
Aug 6, 2021 • 6 tweets • 3 min read
1/x
 A curious Navigational Warning has appeared for what appears to be a series of Space Debris deorbits.
The areas point to deorbit from a ~51-53 degree inclined set of orbits.
#Starlink mass #deorbit?
Some areas line up with ISS passes in the two time windows given, but (cont.) 2/x
 (cont.) but AFAIK nothing will leave the ISS between now and August 10. And the areas south of Alaska do not line up with ISS groumndtracks in the given two time windows.
So my guess is multiple #Starlink deorbits (but I might be wrong).
Aug 4, 2021 • 10 tweets • 9 min read
The #Proton-M third stage from the #Nauka launch is now coming down faster and faster.
Current prediction models place reentry within 2 days from now, either late August 5 or early August 6, with the trend in predictions tending towards August 5.
@SSC_NL ImageImage These reentry forecasts are also on my blog:
sattrackcam.blogspot.com/2021/08/proton…
Jun 27, 2021 • 5 tweets • 4 min read
1/x
 Navigational Warnings have appeared for the @VirginOrbit "Tubular Bells part I" launch on June 30 (a LauncherOne rocket launched from the 'Cosmic Girl' aircraft).
This launch includes #BRIK-II, the first Dutch military satellite, launched for the Royal Netherlands Air Force. ImageImageImageImage 2/x
 "BRIK-II" is a 6U cubesat (about 60 x 30 x 20 cm, 10 kg).
It is named after the very first aircraft, named 'Brik', of the RNLAF predecessor in 1913-1916. It is also the name for a brick, hence the mission patch
(photo of original Brik aircraft: NL Inst. for Military History) ImageImage
May 8, 2021 • 5 tweets • 2 min read
1/x
 Updated map, showing the trajectory of the Chinese #CZ5B rocket (blue lines) over the uncertainty interval in the latest TIP of CSpOC, the US military tracking network.
Within the 12 hr wide uncertainty window, it can fall anywhere on these blue lines. 2/x
 Also shown are cities with populations of 1 million or more in the relevant area between 41.5 N and 41.5 S
May 8, 2021 • 7 tweets • 2 min read
1/x
 Update: de lichtblauwe lijnen tonen waar de Chinese CZ-5B raket mogelijk kan neerkomen: de lijn geeft het traject van de raket over het nog steeds 12 uur grote (!) onzekerheids-interval in tijdstip van de laatste TIP van CSpOC (het Amerikaanse militaire trackingnetwerk). 2/x
 het onzekerheidsinterval loopt van ongeveer 22u NL tijd op de 8e tot ongeveer 11u NL tijd op de 9e.
May 5, 2021 • 5 tweets • 1 min read
Mei 1945: mijn opa en oma (links) na vijf jaar weer herenigd. Vijf jaar waarin mijn opa vanuit Engeland in de Brits/Nederlandse Marine diende terwijl oma en de kinderen in bezet Nederland waren achtergebleven. Image 2/x
 Mijn opa was visser en op zee met de IJmuidense trawler Vikingbank toen de oorlog uitbrak. Noodgedwongen in Aberdeen aangemeerd, om zoals de meeste ontheemde vissers deden, vervolgens in de Kon. Marine de hele oorlog op mijnenvegers gediend.
Sep 27, 2020 • 4 tweets • 1 min read
Dat moet hij wijlen mijn opa en oma eens vertellen, die 5 jaar zonder elkaar doorbrachten, opa in de Britse Marine en oma + kinders in bezet Nederland. Of mijn schoonvader, die in een Jappenkamp zat terwijl zijn vader 1000 km verderop gedwongen aan de Pakanbaru spoorweg werkte. Of aan diegenen die op een gegeven moment in een veewagon voor het laatst mochten knuffelen.
Serieus, als je nu vergelijkt met WO II en stelt dat het nu door corona-maatregelen "erger" is, dan zit er een steekje bij je los. Toondoof en volledig gespeend van beoordelingsvermogen.
Sep 23, 2020 • 6 tweets • 4 min read
Some preliminary results on the earthgrazing #fireball of yesterday morning, from Dutch all-sky #meteor camera images.
Rare case of a meteor that definitely went in and out of the atmosphere again! Just like the famous 1972 Grand Tetons fireball
@MVerstraaten @cgbassa @Doenker Image Even the meteors try to avoid our planet in 2020...
Sep 17, 2020 • 5 tweets • 3 min read
1/4
 Vanavond (do 17e) om 20:19 NL tijd lanceert @SpaceX mogelijk weer een serie van 60 #Starlink-satellieten.
23 minuten later, rond 20:42 NL tijd, is in de avondschemering de #Falcon9 raket *MAAR NOG NIET DE SATELLIETEN* vanuit NL te zien, met het blote oog.
Kaartjes: ImageImageImageImage 2/4
 Waarom alleen de raket en nog niet de satellieten? Dat is omdat de satellieten dit keer pas één uur na de lancering van de bovenste trap van de #Falcon9 worden losgelaten. Als het spul 23 minuten na de lancering over ons komt, zijn ze dus nog niet los van de raket!
Sep 15, 2020 • 4 tweets • 3 min read
Did you know that Geosynchronous #satellites do THE WAVE each day?
I created this animation of movement over a full day to show you.
(dots: satellites. colours: kernel density of that part of the geosynchronous belt)
@drspacejunk @RainerKresken @planet4589 Now you also know why the @SpaceForceDoD wants Navy ranks...it's an ocean out there.... ;-)
Sep 6, 2020 • 4 tweets • 2 min read
And it's back.... Based on when the Chinese 'reusable' spacecraft passed over two potential landing sites, the landing potentially happened either near:
* 1:55 UT on an airfield in the Taklamakan desert;
* 6:45 UT at Dingxin Airbase.
Sep 4, 2020 • 4 tweets • 2 min read
No word on a Chinese launch yet....: And a spaceplane it is!!!!!
xinhuanet.com/tech/2020-09/0…
(HT to @Cosmic_Penguin )
Can't wait to see the first orbital elements.
Sep 3, 2020 • 5 tweets • 3 min read
China might launch an experimental space plane tomorrow, see Cosmic Penguin's thread Based on the NOTAM's, I calculate that tomorrow's mystery Chinese CZ-2F #launch that at the suggestion of @Cosmic_Penguin might be a Chinese #Spaceplane, will go into a ~45 degree inclined orbit (give or take a degree or so):
Aug 29, 2020 • 4 tweets • 4 min read
Looks like there will be another #Minuteman-III #ICBM test from Vandenberg towards Kwajalein in the first week of September, with a ~8100 km range. Navigational Warnings, and a plot of these (with ballistic trajectory)
@wslafoy @ISNJH @mhanham @planet4589 @ArmsControlWonk Navigational WarningsPlot of navigational Warnings 2/2
 The trajectory and stage splashdown zones of this upcoming #Minuteman-III ICBM test launch are comparable to that of the recent August 4 test launch, but with the RV('s) targetting an ~800-900 km longer range, it seems: Image