NASA Scientific and Technical Aerospace Reports

20040121082 Ball Aerospace and Technologies Corp., Boulder, CO, USA
Final Results of the Ball AMSD Beryllium Mirror
Chaney, David M.; [2004]; 1 pp.; In English; Technology Days in the Government, 17-19 Aug. 2004, Huntsville, AL, USA;
No Copyright; Avail: Other Sources; Abstract Only
The 1.4-meter semi-rigid, beryllium Advanced Mirror System Demonstrator (AMSD) mirror completed initial cryogenic
testing at Marshall’s X-ray Calibration Facility (XRCF) in August of 2003. Results of this testing show the mirror to have very
low cryogenic surface deformation and possess exceptional figure stability. Subsequent to this cryogenic testing beryllium was
selected as the material of choice for the James Webb Space Telescope (JWST) multi-segment primary mirror. Therefore, the
AMSD mirror was sent back to SSG-Tinsley for additional ambient polishing to JWST requirements. The mirror was
successfully polished to less than 22nm rms of low frequency error. Those additional results are presented with comparisons
to the JWST requirements.
Author
Beryllium; Cryogenics; Segmented Mirrors; James Webb Space Telescope
20040121099 South Dakota State Univ., Brookings, SD, USA
Development of a Hydrazine/Nitrogen Dioxide Fiber Optic Sensor
Andrawis, Alfred S.; Santiago, Josephine; 2003 Research Reports: NASA/ASEE Fellowship Program; December 15, 2003,
pp. A-1 - A-12; In English; See also 20040121096; No Copyright; Avail: CASI; A03, Hardcopy
Bromothymol Blue (BT)/Bromocresol Green (BG) mixture (1/1) in hydrogel (l/l), produces a blue-green indicator for HZ
and/or NO2. The stability over a two months period of this BT/BG (1/1) indicator solution was tested and no evidence of
performance deterioration was detected. A dual HZ/NO2 prototype sensor utilizing an acid-base indicator was previously
constructed. A monitor and control circuit are also designed, built d tested during the course of this project. The circuit is
controlled with Motorola MC68HC II microcontroller evaluation board to monitor the voltage level out of the photodetector.
Low-pass filter and amplifier are used to interface the sensor’s small voltage with the microcontroller’s AD input. The sensor,
interface circuit and the microcontroller board are then all placed in one unit and powered with a single power supply. The
unit is then tested several times and the response was consistent and proved the feasibility of dual ‘J@ leak detection. Other
sensor types, suitable for silica glass fiber, smaller in size, more rugged and suitable for use on board of the Space Shuttle and
missile canisters, are then proposed.
Author
Detection; Fiber Optics; Gas Detectors; Glass Fibers; Nitrogen Dioxide; Hydrazines
20040121106 Oklahoma Baptist Univ., Shawnee, OK, USA
Development of Charge to Mass Ratio Microdetector for Future Mars Mission
Chen, Yuan-Lian Albert; 2003 Research Reports: NASA/ASEE Fellowship Program; December 15, 2003, pp. B-1 - B-9; In
English; See also 20040121096; No Copyright; Avail: CASI; A02, Hardcopy
The Mars environment comprises a dry, cold and low air pressure atmosphere with low gravity (0.38g) and high resistivity
soil. The global dust storms that cover a large portion of Mars are observed often from Earth. This environment provides an
ideal condition for turboelectric charging. The extremely dry conditions on the Martian surface have raised concerns that
electrostatic charge buildup will not be dissipated easily. If turboelectrically generated charge cannot be dissipated or avoided,
then dust will accumulate on charged surfaces and electrostatic discharge may cause hazards for future exploration missions.
The low surface on Mars helps to prolong the charge decay on the dust particles and soil. To better understanding the physics
of Martian charged dust particles is essential to future Mars missions. We research and design two sensors, velocity/charge
sensor and PZT momentum sensors, to measure the velocity distribution, charge distribution and mass distribution of Martian
wed dust particles. These sensors are fabricated at NASA Kenney Space Center, Electrostatic and Surface Physics Laboratory.
The sensors are calibrated. The momentum sensor is capable to measure 45 pan size particles. The designed detector is very
simple, robust, without moving parts, and does not require a high voltage power supply. Two sensors are combined to form
the Dust Microdetector - CHAL.
Author
Charge Distribution; Charged Particles; Electrical Resistivity; Electrostatics; Fabrication; Dust Storms; Sensors
20040121125 NASA Langley Research Center, Hampton, VA, USA
Single-element Electron-transfer Optical Detector System
Jordan, Jeffrey D., Inventor; June 15, 2004; 12 pp.; In English; Original contains black and white illustrations
Patent Info.: Filed 13 Mar. 2002; US-Patent-6,750,438; US-Patent-Appl-SN-097702; US-Patent-Appl-SN-276568;
NASA-Case-LAR-16279-1; No Copyright; Avail: CASI; A03, Hardcopy
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