1. Deployable Sunshield & LAD Deployment Mechanism Li Xiao, Wang Haowei, Zhang Xiaoli Institute of Spacecraft System Engineering,CAST 2015.10.27

2. 2 After the meeting in Rome, What we did:  Deployable sunshield;  LAD panels with 40 modules in eXTP.

3. 3 Two solutions:  Type 1: deployable sleeve framework with multi-layer thin film 1 、 Deployable Sunshield Mechanism

4. 4 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: 40m 2 Increasing air resistance,influence on the satellite life.

5. 5  Type 2: sunshield panel using hinges 1 、 Deployable Sunshield Mechanism

6. 6  Type 2: sunshield panel using hinges 1 ） 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: 13m 2 4 ） Using the same HDRMs with LAD, additional HDRM for controlling the deployment sequence between the sunshield and LAD. 1 、 Deployable Sunshield Mechanism

7. 7  Trade-off ItemType1: sleeve framework with thin film Type2: panel using hinges Area40 m 2 which will result in more air resistance 13 m 2 ComplexityComplex Additional HDRMs for mask, and mechanisms for shape control. simple MassAbout 50KgAbout 25Kg Drive unitMotor+controllerSpring No sunshine gap, covered fully Not fully covered, the edge of LAD will be uncoverd 1 、 Deployable Sunshield Mechanism Type 2 is better.

8. 8  Similar products we have designed: 1 、 Deployable Sunshield Mechanism Solar wing with sleeve framework Deployable panel with thin film

9. 2 、 LAD Deployment Mechanism 2.1 、 Design Description-LAD 9  2 wings with 4 panels: >3 m 2 effective area;  each panel: 10 modules.

10. 2 、 LAD Deployment Mechanism 2.1 、 Design Description-LAD 10 within the envelope of launcher （ Φ3800mm)

11. 2 、 LAD Deployment Mechanism 2.2 Design Description-Deployment Hinge(DM) 11  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.

12. 2 、 LAD Deployment Mechanism 2.3 Design Description-HDRM 12 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 。

13. Configuration 4 Panels, 40 Modules Each Panel assembled 10 Modules Type 1:A-frame connection 2 、 LAD Deployment Mechanism 2.4 Design Description- LAD panel structure

14. Four Joints: One 0 DOF Joint Two 1 DOF Joints One 2 DOF Joint 2 、 LAD Deployment Mechanism 2.4 Design Description- LAD panel structure Type 2:Kevin connection

15. Three Joints V Block + Ball Valve With Different Angle 2 、 LAD Deployment Mechanism 2.4 Design Description- LAD panel structure Type 3:Boyes connection

16. 16  Trade-off(After discussion with Berend) ItemType1: A-framework Type2: Kevin Type3: Boyers Load capablity542 Floating capablity 444 Accuracy344 Manufacture423 Integration difficulty 423 Sum2016 2 、 LAD Deployment Mechanism 2.4 Design Description- LAD panel structure 1:Don’t use, 2:Not good, 3:Good, 4:Nice, 5:Excellent Type 1 is best.

17. Thanks