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

DFH 4 Series Spacecraft Date : 28 Sept 2014
Page 34 of 38

Document or Observation / Event Comment /Assessment
program

It is surprising to see that the SA has been oversized for this
program also and that they introduced an angular offset of
Chinasat 10 40°. Why a so large over performance? Is it due to the fact
Health report that they don’t want to modify the panel lay out and that
Power & Payload they prefer to introduce an offset to match the power need!
(APR 2013-  It seems that the satellite has suffered from single event
Apr 2014)
upset as well as a TWTA automatic switch off/restart. But it
seems that they accept these errors without going further in
the investigation.
Charge current on BCR A not stable. The only conclusion
given is a component Drift due to EMC environment or a
Chinasat 11 thermal effect. I will strongly insist on the fact that this
Health report failure should be analyzed more carefully. Further detailed
shall be given on the thermal aspect as it could be a thermal
(May 2013-
Marc 2014) weakness applicable to some other satellites. It is not clear if
Charge current on BCR A not stable. this is the same anomaly as described in the investigation
DFH4 report above.
Platform It seems that several questions have been raised by other
health report underwriters (Spaceeco, Scor). See DFH4 Platform Health
(July 2014) report dated July 2014.
 Again an offset of 25° on the SA like on China sat 10

10.1 DOCUMENT DFH4 ANALYSIS

This document does have a particular interest, because it summarizes the problems / anomalies on DFH3 and DFH4
series, encountered in the past missions.
 This document shows that CAST presentations for the four satellites under review for this job, are lacking to
present past history and anomalies (including DF H 3) in orbit or during launch, including corrective actions for
future launches.
 Two satellites have been lost, one with a propulsion problem, another with an identified problem and another
one which suffered an anomaly during 12 hours with a cause not disclosed (satellite or operation error?).
 On the nine DFH satellites, two are out of service (short /power subsystem, Software bug in ADCS, Solar array
not deployed, propulsion / contamination issue, SADM issue. One does have a limited life (Helium leakage),
but for four satellites there is no information disclosed.

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Contained therein, for any other purposes without BEAZLEY written consent is prohibited.