Micro-Accelerations on Manned Space Complexes
Development and Manufacturing of the Automatic System for the Measurement of Micro-Accelerations on Manned Space Complexes
Tech Area / Field
- INF-SIG/Sensors and Signal Processing/Information and Communications
- INF-SOF/Software/Information and Communications
- INS-MEA/Measuring Instruments/Instrumentation
- SAT-AER/Aeronautics/Space, Aircraft and Surface Transportation
- SAT-MAS/Manned Space Station/Space, Aircraft and Surface Transportation
- SAT-SAF/Space Safety/Space, Aircraft and Surface Transportation
3 Approved without Funding
Central Research Institute of Machine Building (TsNIIMash), Russia, Moscow reg., Korolev
- Institute of Physics of the Earth, Russia, Moscow
- Kayser-Threde GmbH, Germany, Munich\nEuropean Space Agency / Directorate of Human Spaceflight, The Netherlands, Noordwijk\nBoeing Company, USA, CA, Long Beach\nJapanese Aerospace Exploration Agency, Japan, Ibaraki
Project summaryKnowledge of the levels of microaccelerations (µ-accelerations) on manned space-complexes (MSC), and also of their spectral as well as spatial distributions is required to ensure a successful use of MSC for scientific and applied tasks, and also to check up the residual life of MSC structure.
Valid data on actual µ-accelerations on MSC can be only obtained via their direct measurements in orbital flight conditions and following application of mathematical analysis for processing and interpretation of the measurement results.
The experience of space flights testifies to necessity of special systems application for checkup and diagnostics of µ-accelerations on MSC. French and American units for µ-acceleration measurements were used on board MIR space station. The measuring units have acceptable basic technical characteristics such as dynamic and frequency ranges, sensitivity, response speed, mass-to-volume index, power consumption. However, there are two factors, which testify to necessity of improvement and development of such systems.
First, in order to measure quasi-steady and vibratory µ-accelerations there are (as a rule) used sensors of perse types with their special electronic units. Second, in such systems the signal-conditioning circuit (only) undergoes self-diagnostic tests before measurements while the sensor mechanism is not tested.
In this project, it is proposed to develop a universal Measurement and Information System (MIS) including:
- a typical line of units for µ-acceleration measurement in the dynamic range of (10-5 ÷ 10-1) g and frequency range of (0.01 ÷ 50) Hz; the units shall use an inertial element on pendulum suspension and electro-dynamic balancing (i.e., electro-dynamic compensation of the pendulum suspension deviation);
- ground measurement assurance for examination of basic characteristics of a unit for µ-acceleration measurement (Microacceleration Measurement Unit, MMU), including tests under conditions of µ-gravity environment simulation;
- on-board measurement assurance for testing the functionality of the entire measuring channel at its initial switch on and also for periodic testing of changes in its metrological characteristics during further operation.
The proposed system can be used for diagnostics and monitoring of acting µ-accelerations during initial inspection of MSC on-board equipment in perse dynamic ranges, during configuration changes and/or new systems installation, after maintenance actions accomplishment. The proposed IMS can be also used to support scientific and applied research, including:
- convection and heat-mass transfer in a transcritical liquid, self-spreading high-temperature synthesis;
- production of materials for electronic technology;
- biological and biotechnological studies.
Along with the said applications on MSC, the proposed MIS can be used on small Earth satellites, platforms and other unmanned spacecraft in order to ensure current orientation relative to the velocity of movement as well as for study of the conditions of free-molecular flowing round by rarefied gas.
A wide range of MMU modifications allows also its ground application as:
- a inclination sensor in geological exploration and mining industry - to observe the slope of a bore hole axis from the vertical and to determine horizontal displacements of the segments of a hole;
- a inclination sensor in engineering–geological survey of foundation soil for civil, industrial and hydraulic structures; in designing of anti-landslides/slips means etc. - to record angular displacements in man-made constructions;
- as a horizon scanner sensor in navigation (aviation, navy) and geodesic instruments;
- as a sensor of horizontal accelerations – to record seismic vibrations.
All participants of the proposed project are experienced in development and application of scientific equipment on MSC (including micro-acceleration measurement onboard Mir space station and the ISS), in development testing and metrological studies, in development of methodical base and software for micro-accelerations measurement. Their qualification is quite sufficient for fulfillment of the tasks specified by the project.
Accomplishment of the project is important in view of meeting of the following ISTC goals and objectives:
- give the scientists and experts employed in defence industry an opportunity to apply their knowledge and experience to development of equipment for civil industry and scientific research;
- support applied research and elaboration of some appointed technologies for civil purposes; in particular, the proposed techniques and means can be used for monitoring of dynamic situation on orbital space complexes, for research of weightlessness physics, and also in seismology;
- promote integration of scientists and experts from institutions-collaborators into the world scientific community, encourage participation in international mutually beneficial co-operation.
The scope of activities includes:
- development of recommendations to define the requirements to a measurement & information system for micro-accelerations monitoring (MAMMIS) on board the ISS;
- development of a typical line of µ-acceleration measuring units (MMUs) with a power supply unit and electronic unit for data processing in the ranges: dynamic - (10-5 … 10-1) g, frequency - (0.01 … 50) Hz;
- modernization of existing test stands to ensure determination of basic metrological characteristics of MMU;
- creation of a “free-fall” test stand in order to imitate micro-gravity environment;
- development of software and hardware tools to analyse microacceleration root-mean-square (RMS) spectral distributions for measurement results processing;
- development of structural (block) scheme, principle circuit of and specification requirements to an on-board autonomous MAMMIS;
- development and stand testing of a model on-board device dedicated to MMU calibration.
Cooperation with foreign institutes (collaborators) includes:
- information interchange during the project implementation;
- comments on the annual and final technical reports to be submitted by the participants of the project to ISTC;
- cross checks of the results obtained during the project realization.
A typical line of MMU shall be based on an existing measurement unit designed and being in use for quasi-steady acceleration measurements. Achievement of the threshold sensitivity increase up to 1.0 × 10-9 g to measure quasi-steady micro-accelerations, and extension of the frequency range to 50 Hz for measuring vibratory micro-accelerations is proposed by means of both a sensor mechanism modernization and improvement of the feedback and the amplifier of electronic unit.
The tasks of MMU calibration and the MMU technical performances study are supposed to be accomplished by means of the test facilities of UIPE RAS dedicated to development testing of infra-low frequency gravimeters; creation of a "free-fall" test stand imitating the micro-gravity conditions; development of test methods for sensor calibration.
An on-board autonomous MIS structural scheme, principle circuit and specification requirements shall be developed on the basis of the participants’ wide experience in the field of scientific equipment studies, improvement and testing (in ground and space complexes’ environment).
The proposed system will be able to perform in-flight verification of the sensitivity of the entire measuring channel. The system shall have an electronic device integrated in an MMU. The electronic device shall periodically, during micro-acceleration measurements, create a calibration disturbance w.r.t. pendulum suspension. The disturbance magnitude shall be equivalent to the impact of reference acceleration at calibration under ground gravity conditions.
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