Thread by @brianweeden

1/ (THREAD) Ok, short thread rounding up what we know so far on the #Cosmos1408 breakup, potentially as a result of a Russian ASAT test

2/ A breakup event for Cosmos 1408, a derelict Russian ELINT satellite, was initially reported by @US_SpaceCom in @HoustonChron

3/ Breakup was confirmed by @LeoLabs_Space, and at this point is only a few to couple dozen objects

https://twitter.com/LeoLabs_Space/status/1460295107152949256

4/ Cosmos 1408 was a Tselina-D, which doesn't have a known history of spontaneous fragmentation (from fuel or batteries): ntrs.nasa.gov/citations/2018…

5/ It was also a LARGE spacecraft (~ 2,000 kg) so if it was a hypervelocity collision (large debris or ASAT KKV), we'd expect hundreds to thousands of resulting debris space.skyrocket.de/doc_sdat/tseli…

6/ The ISS will keep passing through the Cosmos 1408 debris field every ~90 min or so for the next day, which is why they've been directed to prep for potential collisions:

https://twitter.com/SpaceflightNow/status/1460302832398123008

7/ It seems Russia posted a NOTAM for a missile launch from 0200-0500Z on 15-17 Nov, which roughly corresponded to a flight test of a Nudol DA-ASAT out of Plesetsk

https://twitter.com/brianweeden/status/1460285435880615937

8/ Russia has tested the Nudol ten or so times since 2014, although to date not attempted an actual intercept that we know of

9/ @planet4589 has lined up the NOTAM with the orbit of Cosmos 1408 to show that it was possible to do the intercept

https://twitter.com/planet4589/status/1460305735317868545

10/ So, to sum up, we know there was a debris event and its PLAUSIBLE it was caused by an ASAT test but do not yet have confirmation. If we get reports of a much larger debris cloud, then that will be a big sign...

11/ ADDENDUM - The US has confirmed it was an ASAT test that created thousands of pieces of debris

https://twitter.com/thesheetztweetz/status/1460330386085531649?t=rVcoic3V_7nPeXs3N6tGAA&s=19