NASA Scientific and Technical Aerospace Reports

network. To achieve these goals, a robust and agile communications system is needed. Advancements in field programmable
gate array (FPGA) technology have made it possible to incorporate major communication and network functionalities in
FPGA chips; thus this technology has great potential as the basis for a reconfigurable communications system. This report
discusses the requirements of future space communications, reviews relevant issues, and proposes a methodology to design
and construct a reconfigurable communications system for small scientific spacecraft.
Author
Communication Networks; Field-Programmable Gate Arrays; Space Communication; Trends
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SPACECRAFT DESIGN, TESTING AND PERFORMANCE
Includes satellites; space platforms; space stations; spacecraft systems and components such as thermal and environmental controls;
and spacecraft control and stability characteristics. For life support systems see 54 Man/System Technology and Life Support. For
related information see also 05 Aircraft Design, Testing and Performance; 39 Structural Mechanics; and 16 Space Transportation and
Safety.
20040068192 Fraunhofer-Inst. fuer Mikrostrukturtechnik, Germany
High Aspect Ratio Hole Array Filters for a Wide Range of Wavelength
Fettig, R. K.; Hein, H.; Schulz, J.; International Thermal Detectors Workshop (TDW 2003); February 2004, pp. P3; In
English; See also 20040068186; No Copyright; Abstract Only; Available from CASI only as part of the entire parent document
Metal mesh filters are used as cutoff and band pass filters for radiation from the infrared to microwaves. Usually they are
constructed of metal films where the thickness is much thinner than the size of the structures. In some instances films thicker
than the size of the apertures are of advantage. Simple theoretical models predict that thick metal films with densely packed
circular or hexagonal holes act as high pass filters. They should exhibit a sharp cutoff and an out of band rejection which is
the better, the larger the aspect ratio of film thickness to hole diameter. The cutoff wavelength is about twice the hole diameter.
The LIGA process that combines E-beam or x-ray lithography with electroplating is well suited to produce filters with the
favorable aspect ratios of > 2:1. With this process filters were produced for the Isophot instrument onboard ESAs ISO
satellite. The filters had hexagonal holes of 80 micron width in a 180-micron thick film. The rejection of radiation of
wavelength > 150 micron is excellent. Recently filters have been produced using E-beam lithography and electroplating
with hole diameters of 1 micron in a 2.5-micron thick gold film with a similarly good rejection for wavelengths > 2 micron.
With these filters the suitability of layout and processes is demonstrated for the entire range from 2 micron to the microwave
region.
Author
Bandpass Filters; Infrared Space Observatory (Iso)
20040070737 Space Systems/Loral, Palo Alto, CA, USA
Sodium Sulfur Cell Technology Flight Experiment
Chang, Rebecca R.; Space Electrochemical Research and Technology: Abstracts; [1991], pp. 45; In English; See also
20040070726; No Copyright; Available from CASI only as part of the entire parent document
A practical and technically low risk sodium sulfur (Na-S) cell experiment has been identified to address all critical issues
related to Na-S battery operation under microgravity conditions. This work was performed by Space Systems/Loral (SS/L)
formerly known as Ford Aerospace Corporation’s Space Systems Division, Sodium Sulfur Battery Flight Experiment
Definition Study (Phase A), and documented in the Phase A final report. The advantage of the Na-S battery for space
applications, and the benefits, justifications, and objectives of the flight experiment were also presented at the IN-STEP 88 and
previous SERT conference. The development of a detailed experiment concept will be performed in the Concept Development
Phase (Phase B); and the final design, fabrication, testing, flight, and data analysis of the experiment will be performed in the
Flight Development and Operations Phase (Phase C/D). This paper summarizes the current status and update of the flight
experiment.
Author
Fabrication; Technology Utilization; Sodium Sulfur Batteries; Aerospace Engineering; Flight Tests
20040070775 NASA Langley Research Center, Hampton, VA, USA
One Idea for a Next Generation Shuttle
MacConochie, Ian O.; Cerro, Jeffrey A.; [2004]; 8 pp.; In English; 63rd Annual Conference of Society of Allied Weight
Engineers, Inc., 17-19 May 2004, Newport Beach, CA, USA
Report No.(s): SAWE Paper-3324; Copyright; Avail: CASI; A02, Hardcopy
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