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Jonathan McDowell

@planet4589.bsky.social

Astrophysicist

18,607 Followers  |  1,949 Following  |  2,775 Posts  |  Joined: 12.05.2023  |  1.9613

Latest posts by planet4589.bsky.social on Bluesky

Alternatively, you could go up two floors from your office and ask your colleague who is moderately well informed on such things if your back of the envelope numbers have any obvious mistakes in them, before bothering the PI

04.08.2025 02:30 β€” πŸ‘ 14    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Well, there's also 2a): first do the best possible assessment based on public info, spending at leat the 20 minutes it took me, and if it's already clear that the answer is 'not feasible', you don't need to do steps 3 onwards.

04.08.2025 02:28 β€” πŸ‘ 13    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Sorry for typo, "Lionel Pitchford" of course

03.08.2025 13:23 β€” πŸ‘ 15    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

NS-34 carried J.D. Russell (space traveler 713), Lionel Pitchfrod (753), Gokhan Erdem (754), Sun Yuchen (Justin Sun; 755), Arvinder Bahal (756) and Deborah Martorell (757) to an apogee of around 106 km. Russell also flew on NS-28 in 2024.

03.08.2025 13:16 β€” πŸ‘ 35    πŸ” 4    πŸ’¬ 1    πŸ“Œ 0

LAUNCH on suborbital tourist mission at about 1243 UTC Aug 3 of Blue Origin's New Shepard flight NS-34.

03.08.2025 12:43 β€” πŸ‘ 35    πŸ” 2    πŸ’¬ 0    πŸ“Œ 0

Great work!

02.08.2025 19:21 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

TLE orbit data now available for the cubesats from the Jul 25 Soyuz launch- 8 days after launch so that's an improvement over recent similar launches. All 18 objects in a 494 x 503 km x 97.4 deg orbit. One of them is Iran's Nahid-2 and the rest are from Russian companies

02.08.2025 15:17 β€” πŸ‘ 31    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

Dragon Endeavour docked with ISS IDA-3 at about 0626:56 UTC Aug 2.

02.08.2025 06:28 β€” πŸ‘ 48    πŸ” 1    πŸ’¬ 1    πŸ“Œ 0

Hard to tell - maybe a bolt came loose or something

02.08.2025 00:39 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

This is already on my website
planet4589.org/space/stats/...

02.08.2025 00:36 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Two catalog numbers extra in the gap between 2025-164A (PRSC-S1) and 2025-166A (Endeavour), providing circumstantial evidence in favor of the theory that there were two Starshield sats, USA 549 and USA 550, aboard the Starlink 13-4 launch.

01.08.2025 17:06 β€” πŸ‘ 31    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

Endeavour (Crew-11) cataloged as 65077, in a 192 x 214 km x 51.6 deg initial orbit

01.08.2025 17:05 β€” πŸ‘ 28    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

LAUNCH at 1543:42 UTC Aug 1 of Dragon Crew 11 from Kennedy Space Center with astronauts Cardman, Fincke, Yui and Platonov

01.08.2025 15:46 β€” πŸ‘ 35    πŸ” 2    πŸ’¬ 1    πŸ“Œ 0

OK, must be one of 2024 Mar 19, 2024 Nov 30 or 2025 Jan 21.

01.08.2025 15:23 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Which launch is that image from?

01.08.2025 15:09 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

LAUNCH at 1835 UTC Jul 31 of Starlink Group 13-4 from Vandenberg. 19 Starlinks aboard; speculation (but no definite evidence yet) that the launch may also have carried some NRO Starshields

01.08.2025 01:38 β€” πŸ‘ 27    πŸ” 1    πŸ’¬ 3    πŸ“Œ 0

Oh c'mon, any self-respecting hostile alien starship would have water reservoirs to dispense a camouflage coma to fool us into thinking it's only a comet...

31.07.2025 20:35 β€” πŸ‘ 33    πŸ” 0    πŸ’¬ 4    πŸ“Œ 0

The China-launched Pakistan Remote Sensing Satellite launched from Xichang is being tracked in a 544 x 555 km x 41.1 deg orbit.

31.07.2025 13:16 β€” πŸ‘ 30    πŸ” 5    πŸ’¬ 1    πŸ“Œ 1

LAUNCH at 0200 UTC Jul 31 of Pakistan Remote Sensing Satellite by KZ-1A from Xichang, China

31.07.2025 03:15 β€” πŸ‘ 26    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

That's great to hear. (About Michele, not about the crap you had to go through)

30.07.2025 19:56 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
Preview
Avi and 3I/ATLAS Avi Loeb has gained a reputation for suggesting and outright claiming things could be alien spacecraft even when there’s little to no objective reason to think so. So when the third interstellar objec...

Just to reiterate for the curious:

While there's *nothing wrong* with thinking about whether some interstellar objects could be alien technology, 3I/ATLAS has had its coma clearly detected since July 3. It's very clearly, *unambiguously*, a comet.

sites.psu.edu/astrowright/...

30.07.2025 18:38 β€” πŸ‘ 135    πŸ” 28    πŸ’¬ 10    πŸ“Œ 2

I mean, JRRT was very much academia! But I get your point. I would rather say: the leadership of modern academia is deeply broken.

30.07.2025 18:56 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

PS Hope to run into you in Bromley when I move there in the new year.

30.07.2025 18:50 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Maybe wait to mock them when you have successfully developed an orbital rocket yourself.

30.07.2025 18:13 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

The Weixing Hulianwang Digui 06 internet satellites cataloged in an 866 x 879 km x 50.0 deg orbit; CZ-8A upper stage in 713 x 865 km. NISAR cataloged in a 734 x 749 km x 98.4 deg sun-sync orbit with 1800 LTDN orbit plane; GSLV upper stage in a similar orbit.

30.07.2025 17:38 β€” πŸ‘ 22    πŸ” 0    πŸ’¬ 0    πŸ“Œ 1

LAUNCH at 1210 UTC Jul 30 of a GSLV Mk II from Satish Dhawan spaceport with the NISAR radar satellite

30.07.2025 13:07 β€” πŸ‘ 34    πŸ” 2    πŸ’¬ 1    πŸ“Œ 0

LAUNCH at 0749 UTC Jul 30 of Weixing Hulianwang Digui 06 zu weixing (Satellite Internet LEO Group 06 Satellites), nine more sats for the Guowang/Xingwang constellation, by CZ-8A from Hainan

30.07.2025 13:03 β€” πŸ‘ 26    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Also I realize that you and Michele are the first ARs that I haven't known personally (at least face-to-face) since Woolley and Bruck, so it's a good thing I'm coming back to the UK so I can fix that..

30.07.2025 06:41 β€” πŸ‘ 5    πŸ” 0    πŸ’¬ 2    πŸ“Œ 0

Congratulations to Prof Dougherty! That is great news.
But I also have to salute Martin Rees' remarkable career and wish him well, he was an important mentor to me in my grad school days.

30.07.2025 06:33 β€” πŸ‘ 9    πŸ” 0    πŸ’¬ 2    πŸ“Œ 0

LAUNCH at 0337 UTC Jul 30 of Starlink Group 10-29 from Canaveral

30.07.2025 03:39 β€” πŸ‘ 25    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

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