NASA STTR 2005 Solicitation


RESEARCH SUBTOPIC TITLE:Space Power and Propulsion
PROPOSAL TITLE:600 Volt Stretched Lens Array for Solar Electric Propulsion

NAME: ENTECH, Inc. NAME:Auburn University
ADDRESS:1077 Chisolm Trail ADDRESS:231 Leach Center
CITY:Keller CITY:Auburn University
STATE/ZIP:TX  76248-7000 STATE/ZIP:AL  36849-5320
PHONE: (817) 379-0100 PHONE: (334) 844-5894

Mark   O'Neill

TECHNICAL ABSTRACT ( Limit 2000 characters, approximately 200 words)
ENTECH, Auburn, NASA, and others have recently developed a new space photovoltaic array called the Stretched Lens Array (SLA), offering unprecedented performance (>80 kW/cu.m. stowed power, >300 W/sq.m. areal power, and >300 W/kg specific power) and cost-effectiveness (>75% savings in $/W compared to planar arrays). SLA achieves these outstanding attributes by employing flexible Fresnel lenses for optical concentration (e.g., 8X), thereby minimizing solar cell area, mass, and cost. SLA's small cell size (85% less cell area than planar high-efficiency arrays) also allows super-insulation and super-shielding of the solar cells to enable high-voltage operation and radiation hardness in the space environment. Recent studies show that SLA offers a 3-4X advantage over competing arrays in specific power for many NASA Exploration missions, and that SLA is ideally matched to Solar Electric Propulsion (SEP) applications, which can save NASA >$10 billion for lunar exploration cargo transportation. In Phase II, ENTECH and Auburn will perform critical ground tests, including an advanced solar concentrator (1 kW, 600 V, color-mixing lenses, multi-junction cells) direct-driving a Hall-effect electric thruster, and SLA/thruster plume interaction tests. After Phase II, SLA for SEP technology will be ready for flight testing in preparation for many NASA, DOD, and commercial missions.

POTENTIAL NASA COMMERCIAL APPLICATIONS ( Limit 1500 characters, approximately 150 words)
The 600 V Stretched Lens Array (SLA) for Solar Electric Propulsion (SEP) technology being developed under this STTR program will have major applications for near-term and far-term NASA Exploration Missions. One major NASA application is SLA for SEP technology applied to reusable cargo tugs, not only for near-term robotic and human missions to the moon, but also for longer term missions to Mars and beyond. One reusable cargo tug using SLA for SEP technology can save NASA over $3 Billion in launch costs alone, compared to conventional chemical propulsion delivery of 110 metric tons of cargo to the lunar surface over a five year period. Other NASA applications of SLA for SEP technology include orbit maintenance for the International Space Station, orbit raising or lowering of spacecraft for science missions in orbit about the earth, moon, planets, or asteroids, and primary propulsion for large-scale deep space science missions.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS ( Limit 1500 characters, approximately 150 words)
Many additional non-NASA applications for the proposed SLA for SEP technology also exist, from LEO to GEO orbit raising for commercial communication satellites to repositioning of DOD space assets to meet specific mission requirements. In addition, several of the new entrepreneurial space and near-space companies are working with our SLA team on near-term large-scale commercial applications of the high-voltage radiation-tolerant SLA for both their SEP and their non-SEP missions. Finally, the Missile Defense Agency (MDA) is also funding development of the radiation-hardened SLA for critical National security applications in space, including DOD spacecraft capable of withstanding the effects of man-made threats, including ground-based lasers or nuclear detonations in low earth orbit. SLA offers unique and substantial survivability benefits over all competing solar array technologies for critical future National security space missions.

NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.

Electromagnetic Thrusters
Electrostatic Thrusters
In-situ Resource Utilization
Launch and Flight Vehicle
Micro Thrusters
Optical & Photonic Materials
Photovoltaic Conversion
Power Management and Distribution
Propellant Storage
Radiation-Hard/Resistant Electronics
Renewable Energy
Semi-Conductors/Solid State Device Materials
Structural Modeling and Tools
Testing Facilities
Testing Requirements and Architectures

Form Printed on 01-23-07 12:19