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Jonathan McDowell‏Подлинная учетная запись @planet4589 32 мин назад

The Hagoromo (STARS-C) tether cubesat @stars_shizuoka from @shizuoka_univ reentered March 2. The sat was deployed from ISS in Dec 2016 and tether deploy command was sent 2017 Sep 11. Not clear if the 100m tether did deploy but there was some change in decay rate


32 мин назад

Here is the height versus time graph for STARS-C from deploy to reeentry


28 мин. назад

STARS-C consisted of two 1U cubesats, 10 cm cubes, connected by a deployable tether. But as in previous cubesat tether tests, the hard bit turned out to be reliable communications between ground and satellite

27 мин. назад

According to http://stars.eng.shizuoka.ac.jp/starsc.html  the change in decay rate is small compared to that predicted for a successful 100-meter tether extension

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Jonathan McDowell‏Подлинная учетная запись @planet4589 10 ч. назад

Two @planetlabs Flock 2e satellites (2e-11/12), deployed simultaneously on 2016 Jun 1, reentered 6.5 hours apart on Mar 3 and Mar 4.

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http://blogs.esa.int/rocketscience/2018/01/12/tiangong-1-reentry-updates/

TIANGONG-1 REENTRY UPDATES

Latest reentry forecast provided by ESA's Space Debris Office, ESOC, Darmstadt, Germany.

Update 6 March 2018

The current estimated window is ~29 March to ~9 April; this is highly variable.

Note: Read our updated FAQ

Reentry will take place anywhere between 43ºN and 43ºS (e.g. Spain, France, Portugal, Greece, etc.). Areas outside of these latitudes can be excluded. At no time will a precise time/location prediction from ESA be possible. This forecast will be updated approximately every week in January and February.

Tiangong-1 reentry window forecast as of 6 March Credit: ESA


Tiangong-1 altitude decay forecast as of 6 March Credit: ESA

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Jonathan McDowell‏Подлинная учетная запись @planet4589 6 ч. назад

Another moderately large object is approaching reentry. The Chang-Zheng-3B Y40 stage was placed in 165 x 40019 km GTO in Dec; now 106 x 4913 km, with actual perigee bouncing around 88 to 140 km range for the past month. Nice example of how elliptical orb sats can have v low peri

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Jonathan McDowell‏Подлинная учетная запись @planet4589 6 мин. назад

Just checked the orbit data, there are currently 8 objects in lower orbits than Tiangong-1. Well, 7 mabye, the Columbia cubesat was expected to reenter about 6 hours ago

4 мин. назад

We have three Flock 2e/2e' cubesats approaching reentry in the coming days and weeks; the small sat AggieSat-4 should come down in a week or so

1 мин. назад

A small piece of debris from a 1970 Agena rocket explosion is coming down soon; 442 debris objects were cataloged from that event, of which 300 are still up after 47 years in space

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Jonathan McDowell‏Подлинная учетная запись @planet4589 12 мин.назад

The 440 kg GRACE 1 science satellite is also approaching reentry in about a week;its sibling GRACE 2 came down in December. They were launched in 20

8 мин. назад

OK I miscounted, with the presumed reentry of cubesat Columbia that's 6 objects ahead of TG-1. Iriidium 23 still has a 585 km apogee but a low perigee so it will also come down this month

2 мин.назад

As Tiangong descends, confusion remains widespread about what we can predict about its reentry. Remember that a 1 hour error in our guessed reentry time corresponds to an 27000 km (17000 mile) error in the reentry position. And currently our estimate has a 2 week uncertainty

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Jonathan McDowell‏Подлинная учетная запись @planet4589 2 ч.2 часа назад

The @UniTurabo Columbia cubesat, the first sat from Puerto Rico, reentered around 1200 UTC Mar 7. It was deployed from ISS in May.

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Obj. 43168 HUMANITY STAR decay prediction: March 29, 2018 ± 7d

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Update: obj. 43040 ALCOMSAT 1 CZ-3B R/B decay prediction: March 10, 2018 UTC 05h32mn ± 2h

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Jonathan McDowell‏Подлинная учетная запись @planet4589 6 ч. назад

I reviewed what different launch providers did with the upper stages that reached orbit in 2017. Overall 36 were left in high orbit, 26 abandoned in low orbit, 26 were safely deorbited at the end of the launch process.


6 ч. назад

Slight correction, I missed two


5 ч. назад

Of the stages left in high orbit, 3 have already reentered. Of the 28 stages left in LEO, 12 have now made uncontrolled reentries.

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Китайский "засланец" 43040 ALCOMSAT 1 CZ-3B R/B несётся над бескрайними пампасами Парагвая
 сегодня в 05:30 UTC.

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Jonathan McDowell‏Подлинная учетная запись @planet4589 5 мин. назад

Object 26870, a Blok-ML rocket stage from a 2001 Molniya comm sat launch, was thought to have reentered last July, but has been rediscovered in orbit - it must have bounced off the atmosphere. Current orbit 124 x 1929 km, heading for reentry for real this time

1 мин. назад

Previous known orbit last July for 26870 was 143 x 37626 km. Sometimes such sats can break up and reenter due to low perigee, but sometimes they just undergo a large orbit change and the tracking network loses them for a while.

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Jonathan McDowell‏Подлинная учетная запись @planet4589 6 ч. назад

The GRACE 1 research satellite reentered on Mar 10, as did the third stage of the CZ-3B that launched Alcomsat 1, which had a perigee around 100 km for its last two days of flight

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Jonathan McDowell‏Подлинная учетная запись @planet4589 20 мин. назад

The USAF ORS-1 imaging satellite reentered Mar 12; it was launched in 2011 and its last orbit boost was in early 2015, with small orbit maintenance burns until late that year.

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Jonathan McDowell‏Подлинная учетная запись @planet4589 15 мин. назад

The @TAMU AggieSat-4 satellite reentered near New Zealand on Mar 12 around 0130 UTC

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Jonathan McDowell‏Подлинная учетная запись @planet4589 11 мин. назад

The @planetlabs Flock 2e-4, 2e'-9 and 2e'-11 cubesats reentered on Mar 11 and 12.

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Obj. 26870 MOLNIYA 3-51 SL-6 R/B(2) decay prediction: March 19, 2018 UTC 06h40mn ± 34h

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Dr Marco Langbroek‏ @Marco_Langbroek 2 ч. назад

My current #Tiangong1 #reentry prediction: April 4 +- 4 days @SSC_NL

Спойлер

[свернуть]

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http://blogs.esa.int/rocketscience/2018/01/12/tiangong-1-reentry-updates/

TIANGONG-1 REEN TRY UPDATES

Latest reentry forecast provided by ESA's Space Debris Office, ESOC, Darmstadt, Germany.

Update 15 March 2018

The current estimated window is ~30 March to ~6 April; this is highly variable.

Note: Read our updated FAQ

Reentry will take place anywhere between 43ºN and 43ºS (which includes, e.g. Spain, France, Portugal, Greece, etc., as well as many other regions and continents see map here). Areas above or below these latitudes can be excluded. At no time will a precise time/location prediction from ESA be possible. This forecast is being updated approximately weekly.


Tiangong-1 reentry window forecast as of 15 March Credit: ESA


Tiangong-1 altitude decay forecast as of 15 March Credit: ESA

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Update: obj. 26870 MOLNIYA 3-51 SL-6 R/B(2) decay prediction: March 17, 2018 UTC 23h13mn ± 2h

"вилка" по времени совсем узкая, сегодня-завтра "сгорит в плотных слоях атмосфэры"...
возможные места "падения":
Tolanaro (крайний юг Мадагаскара): 21h55mn, Rajkot (чуть севернее Мумбаи): 22h08mn, Cape Town: 23h20mn, Doha: 23h36mn, Pointe-Noire (Конго): 00h56mn