Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: BeiDou-G2: Past and Present   In January 2022, the defunct satellite BeiDou-G2 was pulled out of
geostationary orbit by Shijian-21 to a graveyard orbit. For safe docking and
operation, it was necessary to determine the rotation state in advance. In this
paper, we show the evolution of the rotation of the BeiDou-G2 satellite based
on the photometry observation data for the past 10 years. The rotational speed
of BeiDou-G2 was found to be annual oscillation, mainly due to the solar
radiation. Based on the evolution of BeiDou-G2's rotation speed and its orbit,
we confirmed that in the last 10 years, the satellite had six abnormal events.
These abnormal events were mainly due to the increase in the rotation speed
caused by suspected fuel leakages. Additionally, the abnormal events included
one collision in 2012, which was inferred to be the trigger of the fuel
leakages in the following years. No rotational speed abnormalities occurred
again after 2017, probably due to the complete release of the residual fuel.
The parameters and the propagating models after one incidence of solar panel
damage in 2014 and one fragment in 2016, with the standard errors for
propagating over 1 year of the rotational axis less than 3{\deg} and rotational
speed being 0.11{\deg}/s, were believed to be able to satisfy the accuracy
requirements of the rotation state well at the moment of docking.

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The categories of this paper are: hep-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
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The categories of this paper are: q-fin
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The categories of this paper are: comp-gas
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-th
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
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The categories of this paper are: adap-org
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The categories of this paper are: nlin
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The categories of this paper are: atom-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: q-alg