Deployable Sunshield & LAD Deployment Mechanism

Li Xiao, Wang Haowei, Zhang Xiaoli

Institute of Spacecraft System Engineering,CAST

2015.10.27

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After the meeting in Rome, What we did: Deployable sunshield; LAD panels with 40 modules in eXTP.

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Two solutions: Type 1: deployable sleeve framework with multi-layer

thin film

1 、 Deployable Sunshield Mechanism

1 、 Deployable Sunshield Mechanism

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Type 1: deployable sleeve framework with multi-layer thin film

1 ） This sunshield mechanism can make sure both LAD 、 HFA and LFA in the shadow.

in Z, ±15 degree ；in Y,±30 degree ；2 ） Thin film area: 40m2

Increasing air resistance,influence on the satellite life.

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Type 2: sunshield panel using hinges

1 、 Deployable Sunshield Mechanism

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Type 2: sunshield panel using hinges1 ） This sunshield panel can only make sure LAD in the shadow, leaving some gaps uncovered.

2 ） The HFA and LFA are uncovered.

3 ） Panel area in all: 13m2

4 ） Using the same HDRMs with LAD , additional HDRM for controlling the deployment sequence between the sunshield and LAD.

1 、 Deployable Sunshield Mechanism

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Trade-off

Item Type1:sleeve framework with thin film

Type2:panel using hinges

Area 40 m2

which will result in more air resistance

13 m2

Complexity ComplexAdditional HDRMs for mask, and mechanisms for shape control.

simple

Mass About 50Kg About 25Kg

Drive unit Motor+controller Spring

No sunshine gap, covered fully

Not fully covered, the edge of LAD will be uncoverd

1 、 Deployable Sunshield Mechanism

Type 2 is better.

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Similar products we have designed:

1 、 Deployable Sunshield Mechanism

Solar wing with sleeve framework Deployable panel with thin film

2 、 LAD Deployment Mechanism2.1 、 Design Description-LAD

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2 wings with 4 panels: >3 m2 effective area;each panel: 10 modules.

2 、 LAD Deployment Mechanism2.1 、 Design Description-LAD

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within the envelope of launcher （ Φ3800mm)

2 、 LAD Deployment Mechanism2.2 Design Description-Deployment Hinge(DM)

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Bending stiffness: 3E4Nm/rad;Driving torque: 50Nm(Each wing using one drive unit);Accuracy: 0.5arcmin.

At present, the hinge’s precision is 0.02°(with 40℃ thermal deformation), the repeat accuracy is 0.005°.If necessary, in-orbit trimming device and in-orbit precision measuring device, should be provided in order to achieve higher accuracy.

2 、 LAD Deployment Mechanism2.3 Design Description-HDRM

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Each HDRM uses one separation nut. Two LAD panels in one sides shared four separation point, The load capability of a single separation point is about 25000N 。

Configuration

4 Panels, 40 Modules

Each Panel assembled 10 Modules

Type 1:A-frame connection

2 、 LAD Deployment Mechanism2.4 Design Description- LAD panel structure

Four Joints:One 0 DOF Joint Two 1 DOF JointsOne 2 DOF Joint

2 、 LAD Deployment Mechanism2.4 Design Description- LAD panel structure

Type 2:Kevin connection

Three Joints

V Block + Ball Valve

With Different Angle

2 、 LAD Deployment Mechanism2.4 Design Description- LAD panel structure

Type 3:Boyes connection

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Trade-off(After discussion with Berend)

Item Type1:A-framework

Type2: Kevin

Type3:Boyers

Load capablity 5 4 2

Floating capablity

4 4 4

Accuracy 3 4 4

Manufacture 4 2 3

Integration difficulty

4 2 3

Sum 20 16 16

2 、 LAD Deployment Mechanism2.4 Design Description- LAD panel structure

1:Don’t use, 2:Not good, 3:Good, 4:Nice, 5:Excellent

Type 1 is best.

Thanks