1. 1 Copyright © Lavochkin Association, March 2008 10-12 March, 2008 Ljubljana, Slovenia FEDERAL SPACE AGENCY Lavochkin Association CREATION OF HIGH-EFFECTIVE SOLAR POWER SYSTEMS ON THE BASE OF RIGIDIZABLE STRUCTURES – STEP FORWARD IN THE SPACE SOLAR ENERGY DEVELOPMENT

2. 2 Copyright © Lavochkin Association, March 2008 Depletion in the nearest future of tradition power sources such as oil, gas and coal Constantly growing energy needs of the mankind Problem of new effective and available ways of power generation

3. 3 Copyright © Lavochkin Association, March 2008 SOLAR POWER SYSTEMS (SPS) SPACE SPSGROUND SPS SPACE SOLAR POWER STATIONS SOLAR POWER STATIONS POWER SYSTEMS OF SPACECRAFT INDUSTRIAL SPACE POWER SYSTEMS SOLAR POWER CONCENTRATOR COMBINED SPS

4. 4 Copyright © Lavochkin Association, March 2008 BACKGROUND BACKGROUND Scheme of deployable space structure developed in Japan Ultra-lightweight structures technology for space solar power Keith Belvin NASA Langley Sept. 10-12, 2002 Scheme of deployable structure with elliptical solar power concentrators (on the top) and space-based solar power generators for geo stationary orbits [NASA Suntower] SPACE POWER STATIONS

5. 5 Copyright © Lavochkin Association, March 2008 BACKGROUND BACKGROUND SPACECRAFT POWER SYSTEMS Conceptual drawing of Champollion spacecraft intended for Deep space mission using electric propulsion (SEP mission) with deployable and rigidizable solar array

6. 6 Copyright © Lavochkin Association, March 2008 Relatively small sizes of the modern spacecraft complicate delivery into space of large-sized constructions, first of all solar batteries, antennas, telescopes and transport systems such as solar sail with sizes of tens and hundreds of square meters. PROBLEM: On-ground manufacturing of thin-walled deployable or inflatable work pieces, that can be compactly folded, delivered into the orbit and transformed into a fixed construction POSSIBLE SOLUTION:

7. 7 Copyright © Lavochkin Association, March 2008 Main effectiveness criteria of solar power systems low cost of power supply to the consumer simplicity and reliability of operation safety of power delivery to the consumer

8. 8 Copyright © Lavochkin Association, March 2008 New light and high-effective solar arrays require application of flexible panels and new solar cell technologies, such as thin film cells. The main advantages of thin film cells: high power/mass ratio high tolerance to small damages such as micro-meteorite impacts high tolerance to the enhanced radiation substantially lower cost

9. 9 Copyright © Lavochkin Association, March 2008 Comparative technical and economical parameters of the present and prospective solar arrays providing generation of 1 kW of electrical power Type of photovoltaic cell Single-crystal silicon Single-crystal gallium arsenide Amorphous silicon on the thin-film base Array area, m26.062.7410.00 Array mass, kg13.587.595.1 Array specific mass, kg/m22.242.770.51 Specific power of photovoltaic cells, kW/m2 0.1650.3650.09 Specific power of 1 kg of solar array, kW/kg 0.0740.1320.28 Cost of 1 kW of electrical power in the near-Earth orbit, k$ 20052556.5

10. 10 Copyright © Lavochkin Association, March 2008 TECHNICAL REQUIREMENTS TO THE SPACECRAFT SOLAR POWER SYSTEMS The inflatable and rigidizable structure (IRIS) designed as a load-carrying structure of the solar power system should be compatible with thermal and mechanical environment specified for space technique. Inflatable and rigidizable structures should be designed taking into account typical satellite in-orbit environment: radiation, ultraviolet radiation, atomic oxygen debris and meteorites environment OrbitLEOGEO Altitude, km80035794 Orientationpolarequatorial Revolution period 100 min24 h Eclipse duration 34 min1.2 h Temperature limitations ( C) +100/ - 130 +80/ -170

11. 11 Copyright © Lavochkin Association, March 2008 MAIN TASKS OF THE ISTC PROJECTS

12. 12 Copyright © Lavochkin Association, March 2008 ISTC PARTNER PROJECT # 2835 MAIN TASKS OF THE PROJECT #2835 Selection of materials and technologies complying the requirements to the developed structure of the experimental solar array. Determination and experimental confirmation of the required parameters and characteristics. Development and industrial utilization of the rigidizable structure manufacturing technology. Qualification tests of the developed experimental solar array. Determination of the program of the experimental panel in- orbit qualification

13. 13 Copyright © Lavochkin Association, March 2008 ISTC PARTNER PROJECT # 2835 RESULTS OF STUDIES CARRIED OUT WITHIN THE PROJECT #2835 SELECTION OF TECHNOLOGY AND MATERIALS Methods of polymeric materials rigidization in space Chemical methods rigidization as a result of chemical reactions under influence of heating (solar IR- radiation); rigidization as a result of chemical reactions under influence of solar UV-radiation; rigidization under influence of vapours of chemical substances evaporating in space vacuum and diffusing through the wall impregnated with a polymeric binding; irreversible change of the wall's rigidity as a result of polymeric compositions foaming in vacuum, which is accompanied with chemical reactions Physical methods reversible change of the wall's rigidity as a result of physical transformations of polymer under consecutive heating/cooling; irreversible change of the wall's rigidity as a result of physical transformations during removal of low-molecular components from material composition in space vacuum.

14. 14 Copyright © Lavochkin Association, March 2008 ISTC PARTNER PROJECT # 2835 SELECTION OF TECHNOLOGY AND MATERIALS RESULTS OF STUDIES CARRIED OUT WITHIN THE PROJECT #2835 1. In the result of studies compositions of polymer composite materials were developed which can be harden due to physical transformations in polymeric matrix caused by removal of temporary plasticizer in vacuum. 2.Directive technological procedures for manufacturing of fragments of the IRIS panel load-bearing framework according to the basic and reserve variants of rigidization were developed. 3.Systematic studies of materials properties before and after hardening were carried out. 4.Carried out studies showed high reliability of developed methods of structure rigidization and confirmed the possibility of reliable deployment of hardenable structural elements without significant distortion of their shape. 5.Method of industrial producing of the composite material prepreg made of the aramid fabric and polymeric binder on the basis of the polyvinyl alcohol was developed. 6.Technology of manufacturing of the thin-wall tube from the prepreg by high- frequency and thermal pulse welding was developed, and a methodology of assembly and testing of the tubular frame was developed as well.

15. 15 Copyright © Lavochkin Association, March 2008 ISTC PARTNER PROJECT # 2835 At the final phase of the project #2835 models of the solar array experimental panels were developed, manufactured and tested SELECTION OF TECHNOLOGY AND MATERIALS RESULTS OF STUDIES CARRIED OUT WITHIN THE PROJECT #2835

16. 16 Copyright © Lavochkin Association, March 2008 ISTC PROJECT # 2836 MAIN TASKS OF THE FLIGHT QUALIFICATION OF THE EXPERIMENTAL RIGIDIZABLE SOLAR ARRAY to work out the technique of deployment of the rigidizable structures; to work out of the technique of structures rigidization in conditions of the orbital flight; to acquire the IRIS images and their transmission to the Earth; to acquire characteristics of the rigidized structures and their transmission to the Earth

17. 17 Copyright © Lavochkin Association, March 2008 ISTC PROJECT # 2836 MAIN TASKS OF THE FLIGHT QUALIFICATION OF THE EXPERIMENTAL RIGIDIZABLE SOLAR ARRAY The IRIS Demonstrator is intended for in-orbit qualification experiment with the inflatable rigidizable structures. The IRIS Demonstrator is arranged on the Fregat upper stage adapter and it is compatible with Fregat on-board housekeeping equipment

18. 18 Copyright © Lavochkin Association, March 2008 ISTC PROJECT # 2836 IRIS DEMONSTRATOR MISSION PROFILE Flight duration of the Demonstrator with inflatable rigidizable structures should be long enough for deployment of two IRIS panels, fulfillment of all necessary measurements and data transmission to the Earth. Measurements transmitted to the Earth, necessary for the mission fulfillment, should be received by two ground stations.

19. 19 Copyright © Lavochkin Association, March 2008 ISTC PROJECT # 2836 SYSTEM OF DYNAMIC PARAMETERS MEASUREMENT The flight Demonstrator and its measurements system have to correspond to the following success criteria: reception on the Earth of the flight data demonstrating safe deployment of the two IRIS panels; reception on the Earth of the flight data demonstrating the successful rigidization of the inflated rigidizable elements. MAIN TASKS OF THE FLIGHT QUALIFICATION OF THE EXPERIMENTAL RIGIDIZABLE SOLAR ARRAY

20. 20 Copyright © Lavochkin Association, March 2008 ISTC PROJECT # 2836 MAIN TASKS OF THE FLIGHT QUALIFICATION OF THE EXPERIMENTAL RIGIDIZABLE SOLAR ARRAY

21. 21 Copyright © Lavochkin Association, March 2008 ISTC PROJECT # 2836 CONCLUSION Development of solar power system is stipulated by application of new prospective technologies and materials. The qualitative level of the modern and future solar power systems is defined by the level of technical and economical perfection of the developed space technique. Application of new prospective technologies of thin-film photoelectrical converters and rigidizable structures allows to achieve significant increasing of effectiveness of modern solar power systems.

22. 22 Copyright © Lavochkin Association, March 2008 Thank you for your kind attention