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#80
by
Liss
on 28 Dec, 2016 18:41
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BY70-1 - Bayi Kepu Weixing-1
Its full descriptive name is 八一学校科普小卫星 [Bāyī xuéxiào kēpǔ xiǎo wèixīng], that means August 1st School Science Small Satellite.
August 1st is usually linked to PLA
Naturally, because it's PLA birthday. In Russia, it would be School named after February 23 :-)
An its official name seems to be “八一•少年行”卫星 [“Bāyī•shàonián xíng” wèixīng].
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#81
by
edkyle99
on 28 Dec, 2016 21:43
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So this looks like a launch vehicle failure, with a possibility of the satellites salvaging themselves, though that remains to be seen. If not, they'll probably reenter in a few weeks.
I believe this is the first-ever CZ-2D launch vehicle failure since the type started flying in 1992.
Both of China's orbital launch vehicle failures this year from Taiyuan.
- Ed Kyle
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#82
by
vapour_nudge
on 28 Dec, 2016 22:41
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Spaceflightnow have posted a story on this too confirming the failure
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#83
by
baldusi
on 28 Dec, 2016 23:29
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If the satellites salvage themselves, it would be a partial failure?
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#84
by
edkyle99
on 28 Dec, 2016 23:47
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If the satellites salvage themselves, it would be a partial failure?
It all depends on the definition - and there is no common definition.
In my book it would be a
launch vehicle failure with the payloads inserted into an improper orbit. If the payloads are able to raise themselves to their planned orbits with propellant left for the mission, it would
not be a
mission failure. Similar to AV-009, CRS-1, STS-51F, etc.
- Ed Kyle
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#85
by
jcm
on 28 Dec, 2016 23:58
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If the satellites salvage themselves, it would be a partial failure?
It all depends on the definition - and there is no common definition.
In my book it would be a launch vehicle failure with the payloads inserted into an improper orbit. If the payloads are able to raise themselves to their planned orbits with propellant left for the mission, it would not be a mission failure. Similar to AV-009, CRS-1, STS-51F, etc.
- Ed Kyle
Agreed - mostly.
I am counting the launch vehicle as a 75% score (wrong but usable orbit) in my own arcane system which runs from 0% (blew up on pad) to 100% (all payloads separated in right orbit).
That does not, of course, mean that the payload customer would be 75% happy!
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#86
by
Steven Pietrobon
on 29 Dec, 2016 02:15
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I'm calling this one a partial failure, for the moment, since the satellites are in orbit. If the satellites can't get into a usable orbit, then it becomes a failure.
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#87
by
osiossim
on 29 Dec, 2016 03:51
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"usable" orbit should be typical sso for optical remote sensing, not this type of strange orbit.
Probably, the satellites are also designed to work in the typical sso, in terms of power budgets and imagery constraints. I dont know the satellite and the fuel mass but I have doubts if the onboard fuel will be enough to bring the satellites to any intended (target) sso.
Seems like he satellites are "unusable" at the moment an will not be able to return as much image as defined in their contracts.
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#88
by
jcm
on 29 Dec, 2016 03:54
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"usable" orbit should be typical sso for optical remote sensing, not this type of strange orbit.
Probably, the satellites are also designed to work in the typical sso, in terms of power budgets and imagery constraints. I dont know the satellite and the fuel mass but I have doubts if the onboard fuel will be enough to bring the satellites to any intended (target) sso.
Seems like he satellites are "unusable" at the moment an will not be able to return as much image as defined in their contracts.
My calculations indicate the sats *do* have enough prop to get to their target orbit.
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#89
by
jcm
on 29 Dec, 2016 03:55
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BY70-1 - Bayi Kepu Weixing-1
Its full descriptive name is 八一学校科普小卫星 [Bāyī xuéxiào kēpǔ xiǎo wèixīng], that means August 1st School Science Small Satellite.
August 1st is linked to PLA, that explains why the military channel (CCTV 7) had a long report earlier today on this amateur satellite (from which I extracted the picture above of ground test equipment showing amateur band frequencies)
Apparently Bayi is the school that Xi Jinping went to!
http://www.globaltimes.cn/content/1026290.shtml
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#90
by
input~2
on 29 Dec, 2016 06:10
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From the latest TLEs (epoch Dec 29, 05:20 UTC) , it appears that the perigee of Object B has been raised from 213 km to 262 km
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#91
by
input~2
on 29 Dec, 2016 08:51
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and now Object A as well:
Perigee raised from 214 km to 242 km (epoch Dec 29, 08:21 UTC)
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#92
by
Star One
on 29 Dec, 2016 12:23
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I wonder how much useful life they will lose having to achieve their orbits this way.
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#93
by
Phillip Clark
on 30 Dec, 2016 10:57
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Just a thought but I wonder whether the CZ-2D second stage was intended to de-orbit itself after the satellites deployed? If this was the case then the premature shut-down of the verniers prevented this.
Adding to the above after some more thought. Perhaps there was a programming error which led to the verniers being shut down at the same time as the main engine on the second stage? This could have prevented the verniers re-igniting to perform the de-orbit burn.
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#94
by
osiossim
on 30 Dec, 2016 11:30
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Perigee raised to 370 km and to 353 km for both satellites.
The life time increased a bit but, we do not know the configuration of the satellites. The questions remain such as;
1. How much fuel they have to correct the orbital injection error or
2. How much fuel they have to correct the LTAN or
3. How much fuel they need to get out from safe mode or escape from the sun etc.
Thus, the life time of the satellites and the concept of the mission could have been seriously degraded. Apart from that, the ground speed at this orbit is extreamly fast and the payload electronics' clock speed is slow to gather and process any usable data.
As a result, nothing could be gathered from this mission but if China will launch 24 of these satellites, it should not be a problem to lost 2 of them.
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#95
by
baldusi
on 30 Dec, 2016 13:41
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Working orbit was supposed to be a 500km SSO. They had a low perigee, but the apo was fine.
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#96
by
FutureSpaceTourist
on 30 Dec, 2016 14:50
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#97
by
input~2
on 30 Dec, 2016 14:57
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Perhaps there was a programming error which led to the verniers being shut down at the same time as the main engine on the second stage? This could have prevented the verniers re-igniting to perform the de-orbit burn.
Phillip, the verniers started as planned as can be seen in this graph from the launch video:
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#98
by
input~2
on 30 Dec, 2016 15:28
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#99
by
Phillip Clark
on 30 Dec, 2016 15:43
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Perhaps there was a programming error which led to the verniers being shut down at the same time as the main engine on the second stage? This could have prevented the verniers re-igniting to perform the de-orbit burn.
Phillip, the verniers started as planned as can be seen in this graph from the launch video:
In that case, does the video show how far into the burn the verniers shut down compared with the planned shut down?