Author Topic: LIVE: Zenit-3F/Fregat-SB - Angosat-1 - December 26, 2017 (19:00 UTC)  (Read 34226 times)

Offline Star One

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i'm not so sure about power supply system failture. According to quite reliable rumours, they was receiving some corrupted data from the spacecraft between official 'loss of signal' and 'connection restored' statements. According to not so reliable rumour, it was a software mishap.

So there was possible never an issue with the batteries just the software.

Offline input~2

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Quote
Devido ao processo de vaporização de gases, vacumização e uma certa inação do computador de bordo, o satélite por algumas hora deixou de enviar telemetria.
No entanto, as 15h00 de Angola do dia 28, foi restabelecido a telemetria com o Angosat.
Actualmente decorre a normalização dos seus sistemas e subsistemas e o processo de inserção em órbita. O estado do satélite é considerado óptimo.

http://www.ggpen.gov.ao/LerMais/?cd=15

Online Steven Pietrobon

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Bing Portuguese translation:

"Due to the process of vaporization of gases, vacumização and a certain inaction of the onboard computer, the satellite for a few hours stopped sending telemetry. However, at the 15th of Angola on the 28th, telemetry was reinstated with Angosat. At present the standardization of its systems and subsystems and the insertion process in orbit. Satellite status is considered optimal."
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline edkyle99

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Hmmmm.  "Vaporization of gases".  Maybe off-gassing from the satellite confused a guidance system star-tracker, causing the satellite to go into some type of safe mode?  Just a guess, and probably wrong.

 - Ed Kyle

Offline Ben the Space Brit

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I must say that the thought that a satellite's inertial platform either doesn't notice or doesn't initially take action when some factor makes the spacecraft drift off its proper attitude makes me wince.
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Offline SLC

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An update from Anatoly Zak on

http://www.russianspaceweb.com/zenit-angosat-launch.html#1228

"On December 30, Interfax reported that the problems with Angosat-1 had stemmed from incompatibility between standards used by Russian and French-built hardware aboard the satellite. The issue was resolved remotely by specialists at RKK Energia, Interfax said, quoting industry sources."

Offline input~2

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Original Interfax article: http://www.interfax.ru/russia/594045

Quote
Moscow. December 30th. INTERFAX.RU - The problems that arose after the launch of the Angolan communications satellite Angosat were related to the compatibility of Russian and French onboard equipment standards, an informed source told Interfax.
[...] After [Angosat] launch, problems arose due to "inconsistencies" between Russian and French regulations, "the source said.
He clarified that the satellite has components produced in France, whose compatibility with the Russian standards has created difficulties.
"The problem was solved remotely by a group of young Energia employees, who developed the spacecraft," the source said.
« Last Edit: 12/30/2017 09:09 PM by input~2 »

Online FutureSpaceTourist

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Unfortunately, Fregat upper stage (2017-086B) from the 26 Dec AngoSat 1 launch left in an orbit infringing upon GEO Protected Region--perigee only 92 km above GEO. #SpaceDebris (graphic-ECR frame depicting 10 days of the Fregat orbit).  lnkd.in/difEp32

https://twitter.com/shell_jim/status/947900207689338880

Offline rocket-chris

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In a German forum i found a report, that the problem occurred with a star tracker which have a to high resolution. This makes the buffer overflow....

https://www.raumfahrer.net/forum/smf/index.php?topic=14712.75
http://www.sodern.com/website/fr/ref/Optroniques_215.html

Offline input~2

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In a German forum i found a report, that the problem occurred with a star tracker which have a to high resolution. This makes the buffer overflow....

https://www.raumfahrer.net/forum/smf/index.php?topic=14712.75
http://www.sodern.com/website/fr/ref/Optroniques_215.html

I'd seen the original "rumor" reported on NK forum, however it was much criticized there so I wasn't sure how credible it is..

Offline Alter Sachse

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https://twitter.com/RussianSpaceWeb/status/949383061459914753

"...all systems aboard Angosat-1 satellite are operating well."

Offline koshvv

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I'd seen the original "rumor" reported on NK forum, however it was much criticized there so I wasn't sure how credible it is..
It was obvious mockery.

Offline nicp

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Glad to see the satellite was recovered, but does the reported incompatibility between French and Russian equipment perhaps suggest a lack of integration testing?
Where's my Guinness?

Offline smoliarm

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http://nsn.fm/aviation-and-space/istochnik-sputnik-angostat-perestal-funkcionirovat.html

Quote
Source: Angosat satellite ultimately ceased to function

I'd like to note, that I'm not sure how credible this info. The source makes strange (doubtful) statements:

1. The solar panels did not deploy
2. The communication with satellite reestablished on Dec 28 lasted only 15 minutes.

With respect to this info - couple questions:
Is it possible to tell if a satellite in GEO dead or alive - just by observation? Say, by registering its drift?

Also - is there any rule which require GEO-satellite operator report lost control of satellite ?
« Last Edit: 01/12/2018 03:53 PM by smoliarm »

Offline gwiz

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Satellite is still in its drift orbit and has drifted right past its announced location.

Offline hvdh

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I think it's true there is no control.
Looking at STK plots now, since Dec 29 not a single hint of any manoever. Drifting about 3°W/day, now near 3°E, and inclination increasing steadily.

Offline Zenit3F

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I think it's true there is no control.
Looking at STK plots now, since Dec 29 not a single hint of any manoever. Drifting about 3°W/day, now near 3°E, and inclination increasing steadily.

Can you please give me a link to the STK plots?

Offline hvdh

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Offline input~2

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So apparently the commands to the thrusters sent on January 9 to stop the drift and stabilize at 14.5°E in GEO were never received :(
« Last Edit: 01/13/2018 02:17 PM by input~2 »

Online Kosmos2001

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So apparently the commands to the thrusters sent on January 9 to stop the drift and stabilize at 14.5°E in GEO were never received :(

So is apparently lost again?

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