SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 44, ISSUE 8 - April 21, 2006

19 SPACECRAFT INSTRUMENTATION AND ASTRIONICS
Includes the design, manufacture, or use of devices for the purpose of measuring, detecting, controlling, computing, recording, or processing data related to the operation of space vehicles or platforms.

For related information see also 06 Avionics and Aircraft Instrumentation; for spaceborne instruments not integral to the vehicle itself see 35 Instrumentation and Photography; for spaceborne telescopes and other astronomical instruments see 89 Astronomy.

20060010189 Southern Univ., Baton Rouge, LA, USA

Camera Image Transformation and Registration for Safe Spacecraft Landing and Hazard Avoidance

Jones, Brandon M.; Summer Student Research Presentations; August 2005, pp. 36; In English; See also 20060010186; No Copyright; Available from CASI only as part of the entire parent document

Inherent geographical hazards of Martian terrain may impede a safe landing for science exploration spacecraft. Surface visualization software for hazard detection and avoidance may accordingly be applied in vehicles such as the Mars Exploration Rover (MER) to induce an autonomous and intelligent descent upon entering the planetary atmosphere. The focus of this project is to develop an image transformation algorithm for coordinate system matching between consecutive frames of terrain imagery taken throughout descent. The methodology involves integrating computer vision and graphics techniques, including affine transformation and projective geometry of an object, with the intrinsic parameters governing spacecraft dynamic motion and camera calibration. Author

Image Processing; Computer Vision; Cameras; Mars Exploration; Mars Surface; Planetary Atmospheres; Spacecraft Landing; Terrain

20060010217 Harvey Mudd Coll., CA, USA

Activity Scratchpad Prototype: Simplifying the Rover Activity Planning Cycle

Abramyan, Lucy; Summer Student Research Presentations; August 2005, pp. 29; In English; See also 20060010186; No Copyright; Available from CASI only as part of the entire parent document

The Mars Exploration Rover mission depends on the Science Activity Planner as its primary interface to the Spirit and Opportunity Rovers. Scientists alternate between a series of mouse clicks and keyboard inputs to create a set of instructions for the rovers. To accelerate planning by minimizing mouse usage, a rover planning editor should receive the majority of inputted commands from the keyboard. Thorough investigation of the Eclipse platform's Java editor has provided the understanding of the base model for the Activity Scratchpad. Desirable Eclipse features can be mapped to specific rover planning commands, such as auto-completion for activity titles and content assist for target names. A custom editor imitating the Java editor's features was created with an XML parser for experimenting purposes. The prototype editor minimized effort for redundant tasks and significantly improved the visual representation of XML syntax by highlighting keywords, coloring rules, folding projections, and providing hover assist, templates and an outline view of the code. Author

Roving Vehicles; Mars Exploration; Document Markup Languages; Parsing Algorithms; Syntax

20060010496 Hypersonic Technology Goettingen, Lindau, Germany

Controlled Hypersonic Flight Air Data System and Flight Instrumentation

Koppenwallner, Georg; Critical Technologies for Hypersonic Vehicle Development; December 2005, pp. 12-1 - 12-30; In English; See also 20060010486; Original contains color and black and white illustrations; Copyright; Avail.: CASI: A03, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document

The main task of an air data system, namely to deduce from measurement on the body the aerodynamic free stream conditions will be outlined. Emphasis will also be given to the limitations of aerodynamic systems. A short review of the aerodynamic probe functions relating measured quantities to the desired free stream conditions and vehicle orientation will be given. After explaining the principle elements of an air data system the design of individual components will be outlined. The design of an air data system depends strongly on the flight envelope, re-entry trajectory and vehicle structure. Flight envelope and re-entry trajectory influence primarily the sensor range and sensor head design. Vehicle structure has a strong influence on the probe installment. The principal components are: Probe heads, probe mounting elements, sensors, sensor electronics, harness and data acquisition system. In a similar way the design of calorimetric heat flux sensors will be explained. Testing and flight qualification are one of the mayor efforts during development of an air data system and flight instrumentation. Therefore the principal steps for these activities will also be outlined. Derived from text

Air Data Systems; Flight Instruments; Hypersonic Flight; Flight Tests; Flight Control; Data Acquisition

20060010497 European Space Agency. European Space Research and Technology Center, ESTEC, Noordwijk, Netherlands

Flight Experiments for Hypersonic Vehicle Development Expert

Muylaert, J.; Cipollini, F.;Walpot, L.; Ottens, H.; Critical Technologies for Hypersonic Vehicle Development; December 2005, pp. 14-1 - 14-30; In English; See also 20060010486; Original contains color and black and white illustrations; Copyright; Avail.: CASI: A03, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document

The paper addresses the ESA in flight Aerothermodynamic (ATD) research programme referred to as EXPERT: the European EXPerimental Re-entry Testbed. The objective of this in-flight research programme is to design and instrument generic configurations, for inflight measurements of critical ATD phenomena using state-of-the-art instrumentation. Hypersonic flight data are required for improved understanding of the following critical ATD phenomena : a) Transition, b) Catalicity and oxidation, c) Real gas effects on shock wave boundary layer interactions, d) Microaerothermodynamics, e) Blackout. Special attention is given to the design of the flight measurement sensors themselves, their integration into the TPS as well as to the measurement of the free stream parameters during re-entry using an Air Data System. In addition to the procurement of 'good enough' hypersonic data, the EXPERT programme includes also windtunnel testing and numerical simulations to complete the above listed critical ATD validation process including windtunnel to flight extrapolation activities. The present paper will report on: selection of reference mission profiles offered by Volna launcher, geometrical design optimisation of the configuration and elaborate on the embarked payloads for the provision of the hypersonic data associated with the above listed critical ATD phenomena. Author

In-Flight Monitoring; Aerothermodynamics; Air Data Systems; Hypersonic Vehicles; Reentry

20060010539 United Space Alliance, Houston, TX, USA

Advanced GPS Technology For Automated/Autonomous Shuttle Missions

Goodman, John L.; March 18, 2004; 31 pp.; In English; AIAA Houston Section Annual Technical Symposium, 16 Apr. 2004, Houston, TX, USA; Original contains black and white illustrations Contract(s)/Grant(s): NAS9-20000; Copyright; Avail.: CASI: A03, Hardcopy

Test flights of a GPS receiver to replace TACAN began in 1996. Each orbiter has one GPS receiver. After RTF, ramp-up to single string GPS use will commence. Endeavour is undergoing TACAN removal and upgrade to three string GPS. GPS is not used for ascent and is powered on prelaunch to support an emergency landing. GPS has limited use for orbital operations and is not used for Rendezvous and docking. GPS will supplement or replace TACAN, but cannot be used as an MLS replacement. GPS enhances Shuttle navigation and improves safety. State-of-the-art GPS receivers have capabilities that would be useful in supporting automated/autonomous missions. Derived from text

Global Positioning System; Autonomy; Ascent; Space Shuttle Missions; Receivers; Microwave Landing Systems; Flight Tests

20060011007 Indian Space Research Organization, Bangalore, India

High Solar Absorber Coating on Metallic, Semiconductor and Dielectric Surfaces for Optical Attenuation Applications in Spacecraft Systems

Kumar, S. ajith; Viswanathan, M.; Nagendra, C. L.; Sharma, A. K.; Pratap, G.; Patnaik, M. M. M.; Journal of Spacecraft Technology, Volume 16, No. 1; January 2006, pp. 1-7; In English; See also 20060011004; Copyright; Avail.: Other Sources

Multilayer optical coating consisting of metal and dielectric layers have been designed on metallic and dielectric surfaces, which have specular reflection loss less than 1.0% in the solar spectrum covering from 400 to 1100nm. These coatings have been developed using electron beam deposition technique and qualified as per space application requirements, on a wide variety of substrates. The coated stainless steel surfaces have solar absorptance \g 98% and infrared emittance \h 20% which have been successfully used in the star sensor baffles of IRS-P6 and PS. The baffles have shown a light attenuation better than 10(exp -7) over a field angle \g35deg. Author

Solar Energy Absorbers; Metal Surfaces; Dielectrics; Semiconductors (Materials); Optical Materials; Baffles; Wave Attenuation

20060011010 Indian Space Research Organization, Bangalore, India

Studies on Test and Evaluation of N(+)-P Junction Silicon Photo-Detectors for Space Qualification

Karanth, Shivaprasad; Sharma, S. V. K.; Nagendra, C. L.; Journal of Spacecraft Technology, Volume 16, No. 1; January 2006, pp. 41-45; In English; See also 20060011004; Copyright; Avail.: Other Sources

Large area N(+) -P junction Si photo-detectors are fabricated using conventional Si foundry process and opto-electronic properties namely short circuit current density J(sub SC) under AMO illumination, dark current I(sub D), and spectral responsivity are characterized at different temperatures. It is observed that the shallow junction devices whose junction depths are 0.5 and 0.7 microns have J(sub SC) equal to 36.0 and 40.0 mA/sq cm respectively, and the corresponding I(sub D) being respectively equal to or less than 44nA and 500 nA for an applied voltage of -2 V. The J(sub SC) is found to be weakly dependent on temperature, over the range from 250 to 350 K which is in agreement with theory. The dark current of the devices is seen to vary in a nonlinear way with respect to temperature which has been supported theoretically. The electron damage coefficient of minority carriers is 7.8 x 10(exp -11) for 8 MeV electrons,over a flux of 2 x 10(exp 13) electrons/sq cm. Environmental durability of the detectors is assessed as per the test conditions stipulated for space applications. It is observed that metallization bus bar arid its structure are critical to produce durable detectors against adverse environmental conditions such as high temperature, thermal shock cycling and thermo vacuum baking. Devices with a tri-layer metallization coating, consisting of titanium, palladium arid silver deposited by ion beam sputtering have been able to pass all the environmental tests specified for space qualification without any failure among the lot of devices. Author

Current Density; Dark Current; Electric Potential; Electrical Properties; Short Circuit Currents; Metallizing; Metal Ions; Silicon

Source: NASA