Space Station Applications Research Articles

Design and Implementation of a Generalized Safety Fault Diagnosis System for China Space Station Scientific Experimental Rack.

As astronauts stay in the China Space Station for a long time during the operation phase, how to ensure the long-term safety of the scientific experimental rack (SER) in the field of space application is a problem that needs to be solved urgently. Each SER in the field of space station applications is a complex system that faces risks from different hazards. At present, there is no generalized monitoring and diagnosis system for the common risks faced by the SER. In this paper, a generalized safety fault diagnosis system is proposed to ensure the long-term safe and stable work of SERs in orbit, considering the actual risks faced by the SER. With the design of a generalized main control board, a measurement and control board, and an SSPC (solid-state power controller) board, the software and hardware cooperate to realize the acquisition of various physical quantities, data processing, power supply and distribution management, and other functions. Combined with relevant fault detection algorithms, the real-time detection and diagnosis of the relevant risks, abnormality warnings, and fault disposal operations are realized, which can effectively ensure the safety of the payloads in the field of space application, astronauts, and the space-station system.

Progress and Development Trend of Space Intelligent Robot Technology

Since space intelligent robots are not restricted by physiological conditions, it is an attractive choice for the development of automation technology to use them for space exploration and utilization. It is currently the key development direction of the major space powers over the world. This paper first investigates the robotic manipulators and humanoid robot systems for space station applications and reviews theories and methods for robots to achieve large-range stable motion and intelligent dexterous manipulation. Then, the intelligent robot systems for on-orbit satellite maintenance are reviewed, and the related technologies of multirobot collaboration are analyzed. Finally, we investigate the intelligent robot systems for on-orbit assembly of large-scale spatial structures and summarize the technologies of modular assembly and on-orbit manufacture. Overall, this paper reviews the technological progress and development trends of space robots, which provides a good reference for further technical research in this field.

Progress of Space Medicine Research in China

With the approaching of the Chinese Space Station (CSS) era, the focus of space medicine applications and related research has shifted to addressing the astronauts' health support in long-duration spaceflights, including nutrition, countermeasure against the physiological effects of weightlessness, medical monitoring and support, psychology status, <i>etc</i>., and accordingly the human experiments to simulate long-duration weightlessness have been carried out. Increasingly, basic research has been put forward in the key areas, such as space bone loss, cardiovascular dysfunction and the molecular mechanisms underlying radiobiological effects. Moreover, specific novel research fields, such as hypometabolism technology, were explored. The research projects in the field of space medicine experiment, as an important aspect of the Chinese Space Station's application, have been officially approved and launched.

Weight-Reduction Design Based on Integrated Radial-Axial Magnetic Bearing of a Large-Scale MSCMG for Space Station Application

For space application, weight and power consumption are the key parameters of an actuator for attitude control of spacecraft. In this paper, weight-reduction design based on a novel combined radial-axial magnetic bearing (CRAMB) in a large-scale magnetically suspended control moment gyro (MSCMG) for space station application is proposed. The CRAMB consists of a radial magnetic bearing (RMB) unit and an axial magnetic bearing (AMB) unit. Two CRAMBs can control the 5-degrees of freedom of the high-speed magnetically suspended rotor. According to the requirement of a large MSCMG for a space station, the CRAMB with permanent magnet bias is modeled (based on an equivalent magnetic circuit method), designed, and tested. Compared with the original magnetic bearings in MSCMG fabricated, the number of magnetic pole is reduced from eight to four for RMB unit based on the CRAMB, the weight of magnetic bearings can be reduced from 35.4 to 30.8 kg (reduced by 4.6 kg), and the volume is reduced from $\text{0.00456}$ to $\text{0.00394}\; \text{m}^{3}$ (reduced by 16.3%), when the MSCMG outputs the same angular momentum of 1200 N · m · s and the same torque of 209 N·m. The maximum power consumption of the proposed CRAMB system is decreased by 15.6%.

Ground-Based Durability Projection of ePTFE on ISS Based on Hubble Space Telescope Degradation Data

Ground-based environmental durability tests have indicated that exposing materials in accelerated tests to environmental model predicted spacecraft mission exposures of known degradation sources does not simulate the extent of damage that occurs in the space environment. One approach to overcoming the difficulties in simulating the space environment using ground-based testing is to calibrate the facility using data from actual space-exposed materials to determine exposure levels required to replicate degraded properties observed in space. This paper describes a ground-to-space correlation method that uses a multiple step process to determine the durability of expanded-polytetrafluoroethylene (ePTFE) for International Space Station (ISS) applications based on ground-based X-ray irradiation and heating exposure that simulates bulk embrittlement as occurs in fluorinated ethylene propylene (FEP) thermal insulation covering the Hubble Space Telescope (HST). This method was designed to damage the back surface of equivalent thickness ePTFE to the same amount of scission damage as occurred in HST FEP (based on elongation data) and then correct for differences in ground test ionizing radiation versus space radiation effects, temperature variations, space ionizing radiation environment variations (spacecraft altitude, inclination and duration), and thickness variations. The analysis indicates that after a 10-year mission, the ISS ePTFE will have an extremely embrittled front surface, with surface cracks induced under any given strain, and a very ductile back surface. This study also found that a thermal induced strain of 0.1 will develop in the ePTFE, and under this strain condition, microscopic cracks will start developing very early in the mission at the exposed surface and develop to a depth of approximately 300 am after 10 years.

Multimedial maintenance manuals: International space station applications for on-orbit maintenance support

Maintenance operations related to the elements of the ISS are very complex operations that have to take into account several aspects: the configuration of the elements, the operational capabilities, the timeline of the maintenance task, the tools and support equipment that has to be used and in general all the constraints induced by the on-orbit environment. In this sense, one of the most important aspects of the maintenance operations on ISS is the availability of all the different data related to the on-going task applied on very complex systems like the on-orbit modules are. Most of this data are contained in different databases related to different working groups and many times the essential data are scattered and must be retrieved from all these different sources. The utilization of a Multimedia Maintenance Manual can significantly improve the execution and the efficiency of the maintenance tasks on the ISS when these data are collected on a multimedial support and presented in conjunction with animated video sequences showing the task to be performed. The ISS Node 2&3 Program will be used as reference for the development of the Multimedia Maintenance Manual.

Nonsteady behaviour of solar dynamic power systems with Stirling cycle for space stations

In the first part of this paper, a solar dynamic power system with a Stirling engine for space station application is described. Its unsteady behaviour is theoretically modelled and numerically simulated for four representative orbit configurations. The results are compared to that of a solar dynamic power module with a Brayton gas turbine. In the second part, it is shown that the complex nonsteady behaviour of solar dynamic power modules with either the Brayton cycle or Stirling cycle can be analysed in a simplified way with sufficient accuracy for practical purposes on the basis of parametrizations and simple energy balances.

Identification and status of design improvements to the NASA shuttle EMU for International Space Station application

To meet the significant increase in EVA demand to support assembly and operations of the International Space Station (ISS), NASA and industry have improved the current Shuttle Extravehicular Mobility Unit (EMU), or “space suit”, configuration to meet the unique and specific requirements of an orbital-based system. The current Shuttle EMU was designed to be maintained and serviced on the ground between frequent Shuttle flights. ISS will require the EMUs to meet increased EVAs out of the Shuttle Orbiter and to remain on orbit for up to 180 days without need for regular return to Earth for scheduled maintenance or refurbishment. Ongoing Shuttle EMU improvements have increased reliability, operational life and performance while minimizing ground and on-orbit maintenance cost and expendable inventory. Modification to both the anthropomorphic mobility elements of the Space Suit Assembly (SSA) as well as to the Primary Life Support System (PLSS) are identified and discussed. This paper also addresses the status of on-going Shuttle EMU improvements and summarizes the approach for increasing interoperability of the U.S. and Russian space suits to be utilized aboard the ISS.

EVA suit 2000: A joint European/Russian space suit design

A feasibility study in 1992 showed the benefits of a common European/Russian space suit development, EVA Suit 2000, replacing the Russian space suit Orlan-DMA and the planned European Hermes EVA space suit at the turn of the century. This EVA Suit 2000 is a joint development initiated by the European Space Agency (ESA) and the Russian Space Agency (RKA). The main objectives of this development program are: • • first utilization aboard the Russian Space Station MIR-2 • • performance improvement with respect to current operational suits • • development cost reduction. Russian experience gained with the present extravehicular activity (EVA) suit on the MIR Space Station and extensive application of European Technologies will be needed to achieve these ambitious goals. This paper presents the current status of the development activities, the space suit system design and concentrates in more detail on life support aspects. Specific subjects addressed will include the overall life support conceptual architecture, design features, crew comfort and operational considerations.

Robotic vision technology for space station and satellite applications

This paper presents the robotic vision technologies newly developed for satellites and space station robotic applications at the Pattern Analysis and Machine Intelligence (PAMI) Laboratory of the University of Waterloo and at the Vision, Intelligence and Robotics Technologies Corp. (VIRTEK). The first part of the paper presents how the PAMI-VIRTEK Vision technologies are engineered to support the STEAR (Space Station, Strategic Technologies in Automation and Robotics Program) sponsored by the Canadian Space Agency. The second describes the use of stereo CCD camera for sensing the deformed shape of a third generation satellite. It addresses the notion of shape interpolation and error reduction.

High-Efficiency Solar Dynamic Space Power Generation System

Space power technologies have undergone significant advances over the past few years, and great emphasis is being placed on the development of dynamic power systems at this time. A design study has been conducted to evaluate the applicability of a combined cycle concept—closed Brayton cycle and organic Rankine cycle coupling—for solar dynamic space power generation systems. In the concept presented here (solar dynamic combined cycle), the waste heat rejected by the closed Brayton cycle working fluid is utilized to heat the organic working fluid of an organic Rankine cycle system. This allows the solar dynamic combined cycle efficiency to be increased compared to the efficiencies of two subsystems (closed Brayton cycle and organic fluid cycle). Also, for small-size space power systems (up to 50 kW), the efficiency of the solar dynamic combined cycle can be comparable with Stirling engine performance. The closed Brayton cycle and organic Rankine cycle designs are based on a great deal of maturity assessed in much previous work on terrestrial and solar dynamic power systems. This is not yet true for the Stirling cycles. The purpose of this paper is to analyze the performance of the new space power generation system (solar dynamic combined cycle). The significant benefits of the solar dynamic combined cycle concept such as efficiency increase, mass reduction, specific area—collector and radiator—reduction, are presented and discussed for a low earth orbit space station application.

THE SALISBURY HAND

In the early 1980s, mechanical hands were little more than two‐fingered grippers, or quick‐disconnect wrists with different tools for each job. Today, thanks to engineering ingenuity, shrinking components and government funding for space station and other applications, they are becoming much more. One example of such evolving technology is the Salisbury Hand.

Gram staining apparatus for space station applications

A self-contained, portable Gram staining apparatus (GSA) has been developed for use in the microgravity environment on board the Space Station Freedom. Accuracy and reproducibility of this apparatus compared with the conventional Gram staining method were evaluated by using gram-negative and gram-positive controls and different species of bacteria grown in pure cultures. A subsequent study was designed to assess the performance of the GSA with actual specimens. A set of 60 human and environmental specimens was evaluated with the GSA and the conventional Gram staining procedure. Data obtained from these studies indicated that the GSA will provide the Gram staining capability needed for the microgravity environment of space.

Spacecraft mass property identification with torque-generating control

Previous studies indicated that an applied force was necessary to perform in-flight identification of the mass and center of mass of a spacecraft. This paper shows that the mass and center of mass of a rigid spacecraft can be determined using only torque-producing actuators such as control-moment gyros or reaction wheels, and commonly available sensors, e.g., rate gyros and accelerometers. A space-station application is presented.

New generation optical star trackers for scientific payloads

The paper represents new generation of star trackers for astroorientation of satellites of the SPECTR series, i.e. the carriers of scientific payloads within the framework of the Intercosmos program. The system is designed for the new X-ray orbiting observatory SPECTR - RENTGEN - GAMMA. The architecture and the implementation of certain blocks of the intelligent astronavigation system are described. It is based on CCD sensors for obtaining images from point and extended optical sources. The implementation of digital image processing and the identification of observed stellar configuration into the onboard stellar catalog make the system entirely autonomous. The automatic identification and the flexible system control ensure work without preliminary instructions and refer the system to new generation sensors with artificial intelligence. The system works in the following modes: • — tracking of point sorces; • — tracking of extended sources; • — optical navigation. This system can be used for both three axial stabilization and spinrotating satellites. The modular principle of the system, the availability of image processing and recognition, the onboard catalog memory and the operational modes of the system define it as multifunctional one and enable its adaptation to robotic identification and positioning vision technology for space station applications.

Simulation of a flexible arm robot for space station applications

A Flexible Arm Robot (FAR), which could be attached to the Space Station, could be used for reaching many locations in the vicinity of the Space Station without the need for astronauts in space suits to perform extravehicu lar activity. FAR is a tube-shaped robot consisting of many stacked segments which are individually controllable. Each segment has six degrees of freedom. Because this robot has many degrees of freedom, new algorithms were needed to control it. A graphical model and a mathe matical model (direct and inverse kinematics) of FAR have been developed. Based on these two models, a software package for simulating this Flexible Arm Robot on a computer system has been made. FAR and the two models are briefly described in this paper.

New group advices on Space Station

Scientific uses o f the proposed space station will be reviewed periodically by a new committee appointed by the National Aeronautics and Space Administration (NASA) in February. The Space Station Science and Applications Advisory Subcommittee will channel to NASA's Office of Space Science and Applications (OSSA) views of the scientific community on how the station can be used for scientific research and applications. The focus is equipment development, as well as operational procedures and capabilities.

Current military/government applications for speech recognition

This paper presents an overview of several military/government programs in which SCI Technology, Inc. has implemented and tested its speech recognition system. Included are: (1) the Speckled Trout (U.S. Air Force), (2) LHX (Light Helicopter Experimental, U.S. Army), (3) Space Shuttle (NASA), (4) Space Station, (5) AFTI F‐16, and (6) Advanced Tactical Fighter (ATF). Some programs consist of technology demonstrations, while others involve flight testing, and one, Speckled Trout, operationally installing and utilizing a system on a continual basis. In some cases, the hardware consists of a SCI Voice Control Unit (VCU‐5137) and others, a Voice Development System (VDS‐7001). For example, the Space Station application consisted of implementing a VDS in a power system monitoring and switching network in which power switches and loads could be controlled by verbal commands. In another application, two VCUs have been delivered to NASA for future Shuttle flights in which the remote controlled cameras on board will be manipulated (switched, positioned, and focused) using speech, freeing the astronauts' hands for more manually oriented tasks such as controlling the mechanical arm in the cargo bay. The LHX applications included interrogating various on‐board systems (e.g., electrical, hydraulic, transmission) by speech commands and having the system status appear on video monitors. The Speckled Trout program is the first operational speech recognition system to be installed in an aircraft as an integral component of the aircraft's systems. Three VCUs are part of an integrated radio and navigational aides control system in which the system control can be either manual or by voice commands. However, since installation several months ago, the crew reports that radio control has been carried out almost exclusively by verbal commands. The AFTI F‐16 program includes integrating a VDS as part of a flight simulator for testing and evaluation. The ATF program has only recently started and will involve integration as part of an advanced cockpit. This paper will also discuss the evolutionary process that has proven essential to the successful application of speech recognition technology into military and governmental systems of the future.

Conceptual fluid-dynamic heat rejection system for Space Station application

A new type of fluid dynamic heat rejecting system employing heat pump heat rejectors is proposed for a future large scale space station in which more than a hundred kilowatts of heat energy will be dissipated in space. One of the significant features of this new system is that it works both as a radiator and as a refrigerator depending on the thermal environment of the spacecraft. Another feature is that the system can operate at relatively low pressure ranges (less than 1 MPa) by selecting a suitable working fluid, since its thermodynamic cycle consists of two adiabatic and two constant-volume changes under a vapor-liquid coexistent condition. This will lead to a high coefficient of performance and a simplicity of structural design. To verify the validity of this concept, a simple laboratory model of this system was manufactured and its cooling capability demonstrated.

Evaluating space station applications of automation and robotics

A methodology for evaluating and ranking different approaches to automating the functions and tasks planned for a space station is presented. Special attention is given to the impact of advanced automation on human productivity. The methodology is based on the analytic hierarchy process, which permits the introduction of individual judgments to resolve the conflict that arises when incomparable criteria underly the selection process. The overall problem is decomposed into four subproblems focusing on human productivity, economics, design, and operations, respectively. The results from each are then combined to yield the final rankings. To demonstrate the methodology, an example is developed based on the selection of an on-orbit assembly system. Five alternatives for performing this task are identified. Computational results are presented along with their implications. A final parametric analysis shows that the outcome is locally insensitive to all but complete reversals in performance.