3. Structure static test. 4. Solar Sail Material Test. 5. Conclusion

Transcription

1 Ground Testing of Solar Sail Huang Xiaoqi, Liu Yufei Qian Xuesen Laboratory of Space Technology

2 Contents m 8m Solar Sail Prototype 2. Ground Deployment Demonstration 3. Structure static test 4. Solar Sail Material Test 5. Conclusion 2

3 1. 8 8m 8m Solar Sail Prototype Four booms : inflatable boom, fixed to the center structure Position restrict mechanism: restrict the deploy path Four sails: polyimide membrane, rolled on scrolls,8m 8m Limited mechanism: avoid theenwinding. enwinding. 3

4 2. Ground Deployment Demonstration Sail Folding Process Thickness:12.5μm Membrane: Kapton Folding method: skew leaf-out Folding width:25cm L-shape folding Fix the Middle Point Spool to Drum Install to Compact Structure 4

5 2. Ground Deployment Demonstration Fold deployment deployment Ground Test kg 2.0kg kg 1.0kg 25 Time/s Deployment process under 2.5kg loads Vertex position/m The four time displacement curves are close to straight lines, deployment speed is uniform. Deployment process is almost proportioned without serious heap. Sail membrane folded by the skew leaf out method can deploy in a quick and stabilized state. 5

6 2. Ground Deployment Demonstration Fold deployment deployment Ground Test 6

7 3. Structure static test Experimental Apparatus & Procedures Thickness: 12.5 micron Suspended horizontally Tensions from 1~5KGF Tensions act on the acute angle vertexes 3D laser scanner Surphaser25HSX Resolution: distance 0.001mm & angle 1 Fast: 0.5h / test a thin layer of DPT-5 developer 7

8 3. Structure static test Sail Deflection Sail size(%) Deflection / Tension(kgf) Deflection decreases as an exponential curve with the increasing tensile force Tends to stabilize when the tension exceeds 4kgf Considering the planeness of the sail & the buckling of the boom, 4kgf is proper for the scalable solar sail suspended horizontally 8

9 3. Structure static test Membrane Wrinkle The wrinkles emanate from three vertexes, extend to the middle region. Wavelength is short and the peak peakvalley value is high near the vertexes, and the wavelength becomes longer and the p p-vv value becomes smaller toward the middle region. Long and large wrinkles occur along the three sides of the sail. The number of wrinkles and the half wavelength almost keep constant and the peakvalleyy value decreases slightly g y when the tension increases. 9

10 4. Solar Sail Material Test PI Membrane Electron Irradiation 10

11 4. Solar Sail Material Test Test Results The color, transparence and uniformity of the samples do not change obviously. Tensile strength and elongation at break increase first and then decrease, and the peak appears at cm -2. Mechanical property decreases slightly after the irradiation test. 11

12 5. Conclusion The skew leaf out folding is a good method for the large-area sail membrane. The sail can deploy uniformly, rapidly and well-organized without twining. Sail deflection decreases as an exponential curve with the increasing tensile force and tends to stabilize when the tension exceeds to a value. The peak-valley value decreases slightly when the tension increases. Mechanical properties of the polyimide film decrease slightly after the whole test. 12

13 Thank you.