Jonathan McDowellOvjeren akaunt

@planet4589

I'm an astronomer at the Harvard-Smithsonian Center for Astrophysics, working on Chandra and quasars, and commenting on space launches and space activities.

Somerville, MA, USA
Vrijeme pridruživanja: siječanj 2009.

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  1. Do American lawyers really pronounce 'sine die' as 'sye-nee dai'? I hear my old Latin teacher rolling in his grave..

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  2. More cubesat deploys next week from . I believe the NRCSD-17 quad deployer payloads (5 sats) were launched on SpX CRS-19 and the triple deployer payloads (4 sats) were launched on NG-12

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  3. It's unclear which silo the Minuteman was launched from but the previous FTU flight went from LF-04.

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  4. Minuteman III flight FTU-2 was launched from Vandenberg AFB at 0833 UTC Feb 5; the reentry vehicle splashed down near Kwajalein. The FTU series tests replacement components retrofitted to the 1970-era missiles.

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  5. Meanwhile debris object 45181 has also been cataloged, creating a further gap of 49 objects - no idea what for.

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  6. Debris objects 45128-45132 cataloged, leaving gaps 45118-45127 in the catalog presumably reserved for more of the NG-12 cubesats in addition to 45113-17 already associated with the mission. That's 15 gaps, but current info suggests 14 cubesats, so still a mystery to solve..

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  7. The TEPCE cubesat reentered on Feb 1. It was launched last June and was meant to deploy a 1 km tether. A large change in its decay rate on Nov 17 suggests the tether was indeed deployed on that date, leading to its rapid reentry. (TEPCE in red on the plot)

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  8. proslijedio/la je Tweet
    4. velj

    The details of Shadow's epic fail keep getting worse. They deployed the Android app through a free version of TestFairy, which caps the number of users at 200.

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    4. velj

    Strange women lying in ponds distributing swords doesn't look so bad now

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  10. I redid this plot to put payloads at the top of the sandchart, I think that makes it clearer how the Cubesat Revolution in 2017 transformed the low-LEO object population. Again, this is objects < 100 kg and below 600 km.

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  11. You can see that in upper LEO the situation is reversed: small debris dominates the population, and for the massive (100 kg+) objects junk dominates active sats.

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  12. ... low mass in upper LEO

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  13. For completeness, here are corresponding plots for Upper LEO (above 600 km)

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  14. To belabor the point from the first plot, here is a histogram of the current distribution of massive objects in low orbit

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  15. Corresponding data for low mass objects. There is relatively little small debris in Low LEO, it reenters quickly, so the payload/small debris ratio is much bigger than in high orbits

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  16. Medium/high mass (100 kg and up) objects in "Low LEO" (<600 km) versus time. Note that Starlinks now dominate this category: large objects in low orbit.

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    4. velj

    The idea of a Democracy app that doesn't work and then when you call the support line you find it busy because they didn't plan for failure is not just *peak* 2020 but also an obnoxiously on-point metaphor.

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  18. Spaceway 1 continues orbit raising, now 221 km above GEO

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  19. It is now clear (as expected) that official orbit TLE data will not be made available for USA 294 and the associated Electron rocket stages. I encourage the hobbyist community to try and find them!

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  20. proslijedio/la je Tweet
    3. velj

    It looks like USA 271—an active US satellite in GEO—will go on the Lost List (no TLEs for over 30 days) tomorrow. I have marked it as NCE (No Current Elements) to make it easier to see if we ever start receiving new data on the Restricted Objects page:

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