ПБС

[tnt22]

К #874

 Jonathan McDowell @planet4589 7 ч. назад

One of SpaceX's two Starlink prototype satellites, Tintin B, reentered between about 0320 and 0440 UTC Aug 8.  Tintin A will be coming down soon too, together with a number of the V0.9 satellites.

[tnt22]

К #875

 Jonathan McDowell @planet4589 8 авг.

The @AerospaceCorp Aerocube-10a cubesat carries 29 small passive high-drag subsatellites used to probe the density of the upper atmosphere. 3 have been ejected so far and the 2nd one reentered today. Aerocube-10a and 10b remain close to their deployment orbits.

[tnt22]

К #876

 Jonathan McDowell @planet4589 5 ч. назад

Starlink 41 reentered between 1014 and 1038 UTC Aug 9 somewhere on an arc over the Pacific to NW Australia, per http://space-track.org TIP message

[tnt22]

К #878

 Jonathan McDowell @planet4589 5 ч. назад

Starlink 22 reentered at 1453 UTC Aug 9 over Sichuan

[tnt22]

 Joseph Remis @jremis 11 ч. назад

Obj. 44242 STARLINK-28 decay prediction: August 15, 2020 UTC 11h48mn ± 35h.
Prediction assuming no further maneuvering until decay.

Запуск 2019-05-24, объект 2019-029H

[tnt22]

К #883

Съёмка в юго-западном Китае

 丘寒 
23:02 10.08.2020

Параметры съёмки:

Nikon D810a, Sigma 20art, 20 мм, ISO3200, F1,8, 5 секунд для одного кадра, изображение 1 представляет собой наложение 10 кадров. Время съемки было около 22:53 по пекинскому времени, 2020.8.9 (14:53 UTC).

[tnt22]

 Joseph Remis @jremis 17 ч. назад

Obj. 44274 STARLINK-62 decay prediction: August 18, 2020 UTC 05h13mn ± 34h.
Prediction assuming no further maneuvering until decay.

Запуск 2019-05-24, объект 2019-029AR

[tnt22]

 Jonathan McDowell @planet4589 6 ч. назад

Following the reentry of Starlink 22 and 41, 5 more V0.9 Starlinks continue to approach reentry

[tnt22]

 Joseph Remis @jremis 4 ч. назад

Obj. 44247 STARLINK-33 decay prediction: August 23, 2020 UTC 01h33mn ± 32h.
Prediction assuming no further maneuvering until decay.

Запуск 2019-05-24, объект 2019-029N

[tnt22]

 Joseph Remis @jremis 7 ч. назад

Obj. 44270 STARLINK-58 decay prediction: August 24, 2020 UTC 13h42mn ± 38h.




7 ч. назад

Maneuvered. Decay now predicted for September 02, 2020.

Запуск 2019-05-24, объект 2019-029AM

[tnt22]

К #879 и #884

 Jonathan McDowell @planet4589 6 ч. назад

Two more V0.9 Starlinks have reentered: Starlink 66 at about 0530 UTC over western Australia, and Starlink 28 at about 0930 UTC over the Eastern Pacific.

[tnt22]

 Joseph Remis @jremis 4 ч. назад

Obj. 43216 TINTIN A decay prediction: August 29, 2020 UTC 14h23mn ± 33h.
Prediction assuming no further maneuvering until decay.

Запуск 2018-02-22, объект 2018-020B

[tnt22]

К #889

 Jonathan McDowell @planet4589 2 ч. назад

Starlink 58 reentered between 0600 and 0720 UTC Aug 23. It is the 7th satellite from the May 2019 prototype launch batch to reenter. 

[tnt22]

 Joseph Remis @jremis 2 ч. назад

Obj. 39482 TKSAT 1 CZ-3B R/B decay prediction: August 31, 2020 UTC 19h00mn ± 36h.

Запуск 2013-12-20, объект 2013-075B

[tnt22]

 Joseph Remis @jremis 1 ч. назад

Obj. 44239 STARLINK-25 decay prediction: August 27, 2020 UTC 18h11mn ± 8h.
Prediction assuming no further maneuvering until decay.

Запуск 2019-05-24, объект 2019-029E

[tnt22]

https://skyandtelescope.org/astronomy-blogs/astronomy-space-david-dickinson/half-ton-ogo1-spacecraft-set-to-reenter/

HALF-TON OGO 1 SPACECRAFT SET TO REENTER

BY: DAVID DICKINSON | AUGUST 27, 202

OGO 1, a bus-sized relic of the early Space Age, is set to reenter in the coming week.


An artist's impression of Orbiting Geophysical Observatory 1 in orbit.
NASA / GFSC

A 56-year-old NASA spacecraft is about to burn up in Earth's atmosphere. Known as Orbiting Geophysical Observatory 1 (OGO 1), it was the first in a series of six observatories launched by NASA in the 1960s — and the last one to drop from orbit.

OGO 1's imminent demise has come to light via the Minor Planet Mailing List (MPML) online message board. Initial postings described a mysterious object listed as C1979M1, spotted by the Catalina Sky Survey (CSS) on the night of August 25–26, that was heading toward Earth. Discussion on the board soon revealed the object's true identity as OGO 1, which had been expected to reenter in August or September.


Astronomers at the University of Arizona's Catalina Sky Survey captured this image sequence revealing the OGO 1 spacecraft (circled) on the night of August 25–26.
Catalina Sky Survey / University of Arizona / NASA

OGO 1 is listed on Chris Peat's Heavens-Above as COSPAR object 1964-054A and NORAD catalog number 00879. According to spacecraft expert Jonathan McDowell, at the moment the spacecraft's wide-ranging orbit, inclined 55° to Earth's equator, carries it from a distant apogee of 83,425 miles (134,260 km) to an unsustainable perigee of just 73 miles (117 km).

The spacecraft passed through its perigee earlier today while over Bolivia, at 15:05 Universal Time (1:05 p.m. EDT). Although its low altitude would ordinarily make it easily visible among the stars, OGO 1 currently swings through perigee over Earth's daytime hemisphere, rendering it invisible in a sunlit sky.


The wide-ranging orbit of OGO 1.
Chris Peat/Heavens-Above

Dynamicist Bill Gray (Project Pluto) uses observer sightings to create orbital elements for asteroids, comets, and satellites. Now, armed with the new OGO 1 positions found by CSS, Gray predicts an atmospheric reentry at perigee over the central Pacific Ocean near French Polynesian on August 29th around 21:00 UT (11 a.m. in Tahiti).

"The perigee being on the day side put the apogee out on the night side, where we could see it," Gray explains. "If it hadn't been for that, we might have had to go with just the last data we had — which were good enough to say it'd reenter in late August, but not much more than that."

The U.S. Defense Department's Combined Space Operations Center (also a clearinghouse for reentry predictions) has yet to list OGO 1 on its Space-Track reentry forecast. This omission is not uncommon, however, for objects in higher orbits.

Gray notes that OGO 1's orbit has changed quite a bit since its launch on September 5, 1964. "This object has been observed a lot by asteroid hunters," he says, who've reported about 500 observations of it over the last five years alone. He adds that observations made after today's perigee should cinch whether reentry is probable on the upcoming August 29th daytime brush with Earth over the Pacific.

A GROUNDBREAKING MISSION

Launched September 4, 1964, from Cape Canaveral atop an Agena B rocket, OGO 1 was designed to study Earth's magnetosphere and its interaction with the Sun-Earth space-weather environment. Weighing in at 1,074 pounds (487 kilograms), OGO 1 is one of the largest artificial objects to reenter since the Chinese space station Tiangong 2 in July 2019. OGO 1 also made one of the first orbital observations of a comet, observing Comet 2P/Encke in the ultraviolet in 1970. Two booms on OGO 1 failed to deploy fully after launch, blocking a horizon sensor and limiting attitude control for the spacecraft. OGO 1 was placed in standby status in 1969 and formally deactivated in 1971.


An Orbiting Geophysical Observatory satellite getting prepped for launch.
NASA / GSFC

OGO 1 represents an era of the early Space Age, but even-older satellites are still orbiting Earth. For example, the first Canadian satellite, Alloutte 1 (ID 1962-049A/424), was launched from Vandenberg AFB in California in 1962. It's still worth tracking down with binoculars on a clear night. And the oldest satellite still in orbit? That title goes to Vanguard 1, launched from Cape Canaveral on March 17, 1958. Definitely an oldie, it's only the fifth object to orbit Earth and boasts the incredibly low NORAD catalog number of 00005! Vanguard 1 is expected to remain in orbit for another 180 years, through the end of the next century. Obviously, they built 'em to last back in the day — when mission designers didn't think much about space debris or planning for a controlled deorbit at the end of a satellite's useful life-span.

Amateur satellite-tracking is as old as the Space Age. Early volunteers for Project Moonwatchtracked and verified the very first artificial satellite (including Sputnik 1) beginning in the late 1950s. Today, satwatchers still track missions in orbit, hunt for classified satellites such as the U.S. Air Force's X-37B, and confirm (or dispute) claims of satellite launches by North Korea, Iran, and Israel. Today much of the online discussion concerning satellite tracking revolves around the SeeSat-L message board.

This bit of satellite-sleuthing by volunteer observers online and in the field for the recovery and reentry of OGO 1 shows that sky-watchers still provide a valuable service when it coming to following what's up there in orbit.

[tnt22]

К #895

Цитата  Jonathan McDowell @planet4589 2 ч. назад

The NASA scientific satellite Orbiting Geophysical Observatory 1 was launched on 1964 Sep 5 into a highly elliptical orbit with a 149385 km apogee. Initial orbital inclination was 31 degrees. The satellite stopped transmitting on 1972 Feb 15, and has been space junk since then.


1 ч. назад

It was tracked by NASA while active, but not regularly by NORAD because of its high orbit. It was lost from 1972 to 2000 and then rediscovered as space tracking improved. The orbit changes due to the Kozai effect: lunar perturbations make coupled changes in  e and i


1 ч. назад

OGO 1's orbital inclination is now 55 degrees as a result of these perturbations. The perigee dipped low enough lately for decay to take over. A few minutes ago OGO 1 passed through what is almost certainly its final apogee. It is now beginning a death plunge towards the Pacific


1 ч. назад

According to calculations by Bill Gray it wil enter the atmosphere TOMORROW, Aug 29, at 2043 UTC over 15 S 152W and burn up over French Polynesia


1 ч. назад

The satellite has a mass of half a tonne (487 kg in fact) and is a box with booms sticking out that span 12 metres.


52 мин. назад

OGO 1 orbits the Earth very fast at perigee but very slow at apogee, which leads to a really weird trajectory in a coordinate system that rotates with the Earth




51 мин. назад

Approximation to the final plunge




43 мин. назад

Here are the measured values of OGO-1's perigee, apogee, and the average of both versus time showing effects of lunisolar perturbations.  Note the average (equivalently the orbital period) is dead constant until recent months when peri got low enough that atmo sunk its teeth in




41 мин. назад

During the last low perigee phase in 2006, min peri was about 2000 km, so not much drag




40 мин. назад

This time it wasn't so lucky. The effects are complex, depends on orbit orientation rel to moon and so on, so not exactly periodic. This time peri goes negative.

[tnt22]

 Jonathan McDowell @planet4589 3 мин. назад

Object 43598, one of four small satellites ejected by hand during a Russian ISS spacewalk in Aug 2018, reentered on Aug 24. The satellite is probably Tanyusha  YuZGU No. 4 (Radioskaf RS-9) although there was some confusion about the tracking.

[tnt22]

К #886

 Jonathan McDowell @planet4589 32 мин. назад

Another of the Starlink prototypes is down: Starlink 62 reentered over the Pacific at around 0000 UTC Aug 29.

[tnt22]

 Jonathan McDowell @planet4589 2 мин. назад

OGO 1 should now have reentered the atmosphere over Polynesia after 55.98 years in space.