NASA / TM--2002-211720

A Parametric Assessment of the Mission

Applicability of Thin-Film Solar Arrays

David J. Hoffman

Gleru_ Research Center, Cleveland, Ohio

August 2002
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NASA/TM--2002-211720

A Parametric Assessment of the Mission

Applicability of Thin-Film Solar Arrays

David J. t-toffman

Glepa_ Research Center, Cleveland, Ohio

Prepared for the

Space Power Workshop 2002

cosponsored by the Air Force Research Laboratory, USAF Space

and Missile Systems Center, and the Aerospace Corporation

Redondo Beach, California, April 22-25, 2002

National Aeronautics and

Spa ce Administration

Glelm Research Center

August 2002
This report contains preliminary

findings, subject to revision as

analysis proceeds.

NASA Center for Aerospace Information

71121Standard Drive

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Available electronically at http://gltrs.zrc.nasa.gov
A Parametric Assessment of the Mission Applicability of

Thin-Film Solar Arrays

David J. Hoffman

National Aeronautics and Space Administration

Glenn Research Center

Cleveland, Ohio 44135

Summary

Results are presented from a parametric assessment of the applicability and spacecraft-level impacts of very

lightweight thin-film solar arrays with relatively large deployed areas for representative space missions. The most

and least attractive features of thin-film solar arrays are briefly discussed. A calculation is then presented illustrating

that from a solar array alone mass perspective, larger arrays with less efficient but lighter thin-film solar cells can

weigh less than smaller arrays with more efficient but heavier crystalline cells. However, a spacecraft-level systems

assessment must take into account the additional mass associated with solar array deployed area: the propellant

needed to desaturate the momentum accumulated from area-related disturbance torques and to perform aerodynamic

drag makeup reboost. The results for such an assessment are presented for a representative low Earth orbit (LEO)

mission, as a function of altitude and mission life, and a geostationary Earth orbit (GEO) mission. Discussion of the

results includes a list of specific mission types most likely to benefit from using thin-film arrays. The presentation

concludes with a list of issues to be addressed prior to use of thin-film solar arrays in space and the observation that

with their unique characteristics, very lightweight arrays using efficient, thin-film cells on flexible substrates may

become the best array option for a subset of Earth orbiting and deep space missions.

NASA/T_2002-211720 1
Note: Specific Pow er (W/kg &W/m^2) reference

assume a 0 85 cell packing factor

15.0% "'il_ " .20.0% 2iMp, G25.0% i o

Cell Efficiency, AM0 @ 28°C

35.0 %

NASA/T_2002-211720 2
NASA/T_2002-211720 3
NASA/T_2002-211720 4
NASA/T_2002-211720 5
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August 2002 Technical Memorandum

4, TITLE AND SUBTITLE 5, FUNDING NUMBERS

A Parametric Assessment of the Mission Applicability of Thin-Fihn Solar Arrays

6, AUTHOR(S) WU-755-1A-16-00

David J. t[offman

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8, PERFORMING ORGANIZATION

REPORT NUMBER

National Aeronautics and Space Administration

John El. Glenn Research Center at Lewis Field E----13471

Cleveland, Ohio 44135 - 3191

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/MONITORING

AGENCY REPORT NUMBER

National Aeronautics and Space Administration

Washington, DC 20546-0(101 NASA TM------2002-21 1720

11. SUPPLEMENTARY NOTES

Prepared for the Space Power Workshop 2002 cosponsored by the Air Force Research Laboratory, USAF Space and

Missile Syslerns Cenler, and the Aerospace Corporation, Redondo Beach, California, April 22---25, 2002. Responsible

person, David J. Hoffman, organization code 6920, 216---433----2445.

12a, DISTRIBUTION/AVAILABILITY STATEMENT

Unclassified - Unlimited

Subject Categories: 18 and 20 Distribution: Nonstandard

Available electronicaJly at ['..ttp://glt:.-s._rc.nasa._ov

_l-his publication is ava_ilable from the NASA Center for AeroSpace In*brmadon, 301-621-0390.

12b. DISTRNBUTION CODE

13. ABSTRACT (Maximum 200 words)

Results are presented from a parametric assessment of the applicability and spacecrall-level impacts of very lightweight

thin-film solar mTays with relatively large deployed areas for representative space missions. The most and least attractive

features of thin-film solar aTays are briefly discussed. A c_culation is then presented illustrating that from a solar a'ray

_one mass perspective, larger arrays with less efficient but lighter thin-fihn solar cells can weigh less than smaller arrays

with more efficient but heavier crystalline cells. However, a spacecraft-level systems assessment must take into account the

additional mass associated with solar array deployed area: the propellant needed to desaturate the momentum accumulated

from area-related disturbance torques and to perform aerodynamic drag makeup reboost. The results for such an assessment are presented for a representative low Earth o,l?it (LEO) mission, as a function of altitude and mission life, and a

geostationary Earth orbit (GEO) mission. Discussion of the results includes a list of specific mission types most likely to

benefit from using thin-film arrays. The presentation concludes with a list of issues to be addressed prior to use of thin-film

solar arrays in space and the observation that with their unique characteristics, very lightweight arrays using efficient, thinfilm ceils on flexible substrates may become the best array option for a subset of Earth orbiting and deep space missions.

14. SUBJECT TERMS

Space power; Power generation; _ hotovoltaics; Solar array; Solar panel

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OF REPORT

Unclassified

NSN 7540-01-280-5500

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13

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OF THIS PAGE OF ABSTRACT

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