10-12 March, 200 8 Ljubljana, Slovenia

1Copyright © Lavochkin Association, March 2008

10-12 March, 2008Ljubljana, Slovenia

FEDERAL SPACE AGENCYFEDERAL SPACE AGENCY

Lavochkin AssociationLavochkin Association

CREATION OF HIGH-EFFECTIVE SOLAR POWER SYSTEMS ON

THE BASE OF RIGIDIZABLE STRUCTURES – STEP FORWARD IN

THE SPACE SOLAR ENERGY DEVELOPMENT


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


SOLAR POWER SYSTEMS (SPS)

SPACE SPS GROUND SPS

SPACE SOLAR POWER STATIONS

SOLAR POWER STATIONS

POWER SYSTEMS OF SPACECRAFT

INDUSTRIAL SPACE POWER SYSTEMS

SOLAR POWER CONCENTRATOR

COMBINED SPS


BACKGROUNDBACKGROUND

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


BACKGROUNDBACKGROUND

SPACECRAFT POWER SYSTEMS

Conceptual drawing of Champollion spacecraft intended for Deep space mission using electric propulsion (SEP mission) with deployable and rigidizable solar array


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:


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


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


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 arsenideAmorphous silicon

on the thin-film base

Array area, m2 6.06 2.74 10.00

Array mass, kg 13.58 7.59 5.1

Array specific mass, kg/m2 2.24 2.77 0.51

Specific power of photovoltaic cells, kW/m2

0.165 0.365 0.09

Specific power of 1 kg of solar array, kW/kg

0.074 0.132 0.28

Cost of 1 kW of electrical power in the near-Earth orbit, k$

200 525 56.5


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

Orbit LEO GEO

Altitude, km 800 35794

Orientation polar equatorial

Revolution period

100 min 24 h

Eclipse duration

34 min 1.2 h

Temperature limitations (C)

+100/ -130 +80/ -170


MAIN TASKS OF THE ISTC PROJECTS


ISTC PARTNER PROJECT # ISTC PARTNER PROJECT # 28352835

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



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.





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.



At the final phase of the project #2835 models of the solar array experimental panels were developed, manufactured and tested




ISTC PROJECT # ISTC PROJECT # 28328366

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



Upper Stage “FREGAT”

IRIS 2

Adapter

IRIS 1

Upper Stage “FREGAT”

IRIS 2

Adapter

IRIS 1


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



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.



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.







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.


Thank you for your kind attention

10-12 March, 200 8 Ljubljana, Slovenia

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