Page 28 - test

Ref : CM-DFH4-2014-1
BEAZLEY Issue : 1

DFH 4 Series Spacecraft Date : 28 Sept 2014
Page 26 of 38

CHINASAT 16 Observation Comment /Assessment Cri
isolate the defective thruster.
 LAE failure back-up provided by 10 N  Analysis needed to support this statement.
thrusters
 Page 114. It seems that most of the items are in 
cold redundancy, what about the OBC ? This is
a concern in case of failure on the nominal
path; The redundant configuration will not
know the context at switch ON. What about the
AOCS  patches loaded ? Implication of the FDIR.
Subsystem  Page 124, How all units are powered ? what is See comment on the left.
the redundancy level for DC/DC converters ? ?

Page 121.Operations mode and algorithm.  Explain the difference with The ECM mode and the
FDIR.
 Is there an EDAC protection to correct soft  See comment on the left.
errors and prevent SEU effects?
Avionics  Same question as above for the avionic CMU  See comment on the left.
Subsystem processor/

CHINASAT 16 Observation Comment /Assessment Cri
Avionics  Same question as above for for the avionic  See comment on the left.
Subsystem CMU processor/
 Page 131-135. If we trust all the good wording  To substantiate the heritage, it will be interesting
on these pages, one can conclude that the solar to get feedback for the in-orbit satellites
array is in good shape. (operational performances versus predictions)..

 It will be good to know which cell type they  See comment on the left.
are using, thickness of the cover glass
Solar Array minimum distance between cells and max
voltage between adjacent cells. How the inner
panel is populated.
 The BPBTA is not described.  See comment on the left.
 Deployment mechanism not described.  See comment on the left.
 
 Which units need to be modified to  Is there a need to review unit categorization?
accommodate a 100 Volt bus?

Li-Ion batteries page 143. Some accelerated Qualification status? Are the life test
life test are still on going representative of a GEO mission? Who is the
manufacturer,? Is the production stable?
EPS  What is the fusing strategy ? where the fuses  See comment on the left.
Subsystem are located (hopefully not inside each unit).
 Are the units and spacecraft subject to ESD  See comment on the left.
testing.
 Is the EPS and entire spacecraft tested for 
TDMA mode if applicable?
 Who is in charge of the PCU (is it 
subcontracted?) is it really qualified ?
TC & R  Three command receivers. Three TLM TX  .No major comment at this stage..
Subsystem followed by for SSPA in redundancy (hot or
cold ?).TLM bit rate 4096 bps.
This IPS seems very new and at the top of the
 Used for N & S station keeping. (1250 W). Isp
IPS Subsystem technology.
3000 s. 4 thrusters with a thruster switch unit
It is difficult to understand how they can claim

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