Space Station Payload Accommodation

The unique characteristics of the Space Station are changing the ways payloads are designed and accommodated for orbital flight. Station accommodations need to be versatile and operationally flexible to permit integration of many types of equipment in a variety of modes; and autonomous to render each payload independent or invisible to the rest of the system and other mission equipment. This paper presents the various categories of Space Station payloads, the user facilities that are being designed to accommodate them, illustrates through scientific and commercial scenarios the utilization of those facilities, and identifies the factors that must be considered to make the Space Station an effective tool for the users.     

Reducing the risks of using Ada onboard the Space Station

The Ada programming language was chosen by NASA as the primary computer programming language for the development of new software for the US Space Station. Ada was selected based on the results of investigations coordinated through Johnson Space Center (JSC) and that resulted in the identification of a set of problems and risks associated with using software developed in Ada. Some of the specific solutions to problems identified through these investigations are described. Three areas in which Ada's use poses risks are discussed: real-time process control; the testing and verification of flight software for man-rated systems; and software error detection, identification, and recovery required in safety-critical systems     

Avionics for manned spacecraft

The author describes the avionic equipment for manned spacecraft, past, present, and future. He treats the four classic avionic systems-crew interface, flight control, navigation, and communication-and adds a fifth called subsystem management which refers to the monitoring and reconfiguration of equipment when faults occur. He starts by describing the functions of spacecraft avionics in general. He then discusses what he considers to have been the first manned spacecraft, the X-15. He continues with the early US and Soviet spacecraft (including their space stations), the US shuttle, and the European Spacelab. He concludes with projections for the avionics in future manned spacecraft, such as the US Space Station, a lunar base, and planetary explorers     

The European Columbus Programme

This paper describes the current status of the COLUMBUS Programme, Europe's contribution to the U.S. Space Station, which is being studied under contract to the European Space Agency. Twelve European nations are involved in and are contributing to this new space undertaking. The elements of the COLUMBUS Space Segment presently being considered by ESA are a Pressurized Laboratory Module (4 segment), permanently attached to the U.S. Space Station, dedicated to materials science, fluid physics and compatible life sciences, and a Polar Platform, configured to accommodate Earth observation, meteorology, communications and space science payloads. The reference launch vehicles are the Space Shuttle for the attached Module and Ariane 5 for the Polar Platform. The more recently added COLUMBUS flight configuration, the Man-Tended Free Flyer (MTFF), consists of a combination of two programme elements, the Resource Module and a 2-segment Pressurized Module. It is designed to provide all required resources and services to the various payloads in a continuous microgravity environment to perform material science, fluid physics and compatible life sciences experiments. The MTFF is carried into orbit by the European launcher Ariane 5. As an option, studies of an enhanced ground based EURECA carrier as a small co-orbiting platform, launched by the Space Shuttle, will be initiated. The primary function would be to accommodate space science and/or micro-g payloads. These EURECA studies are performed currently outside the COLUMBUS programme scope, and this option is therefore not addressed in detail in this paper.     

Use of heads-up displays, speech recognition, and speech synthesisin controlling a remotely piloted space vehicle

Experiments are reported in which heads-up displays and voice input/output were implemented on an experimental pilot console. These displays and controls were developed interactively during the simulation of remotely piloted space vehicles (RPSVs) and US Space Station operations. Demonstrated and evaluated were seven heads-up reticle displays, two heads-up data displays, selection of displays by voice command, use of voice command to call for range and rate data, and the voice annunciation of alarms. The simulation laboratory architecture is described     

ASPS-American suborbital passenger system 2005

With the evaporation of funding support for the National Aero Space Plane (NASP), realization of a single stage to orbit night system has been deferred. With the resource down sizing of the NASP management and technical team, development of the NASP concept appears to be delayed beyond the year 2030. To fill this gap for shorter flight times to remote destinations over 8,000 km, it is now proposed to convert the existing NASA shuttle to a passenger configuration and air launch horizontally from a Boeing 747 aircraft as the first stage carrier after climb to launch altitude. This US Shuttle concept may permit the transport of 100 passengers to destinations 10,000 km distant during a flight duration of 90 minutes, and during flight durations of about 120 minutes to any commercial destination on the planet Earth. This long distance system takes advantage of the existing shuttle and Boeing 747 airframe and propulsion technology, and can be implemented within the next decade     

Current status, architecture, and future technologies for theInternational Space Station electric power system

The Electric Power System (EPS) being built for the International Space Station has undergone several significant changes over the last year, as major design decisions have been made for the overall station. While the basic topology and system elements have remained the same, there are important differences in connectivity, assembly sequence, and start-up. The key drivers for these changes in architecture have been the goal to simplify verification, and most significantly, the introduction of extensive Russian participation in the program. Having the Russians join the international community in this project has resulted in an expanded station size, larger crew, and almost doubled the observable surface of the Earth covered by the station. For the power system it has meant additional interfaces for power transfer, and new challenges for solar tracking at the higher inclination orbit. This paper reviews the current architecture and emphasizes the new features that have evolved, as the design for the new, larger station has developed. Additionally, the possible application of developing technology to the station, and other future missions is considered     

Multibody dynamics and robust control of flexible spacecraft

The paper focuses on an approach to the study of the dynamics and control of large flexible space structures, comprised of subassemblies, a subject of considerable contemporary interest. To begin with, a relatively general Lagrangian formulation of the problem is presented. The governing equations are nonlinear, nonautonomous, coupled, and extremely lengthy even in matrix notation. Next, an efficient computer code is developed and the versatility of the program illustrated through a dynamical study of the first element launch (FEL) configuration of the Space Station Freedom, now superseded by the International Space Station. Finally, robust control of the rigid body motion of the FEL configuration using both the linear-quadratic-Gaussian/loop transfer recovery (LQG/LTR) and H_∞ procedures is demonstrated. The controllers designed using the simplified linear models, prove to be effective in regulating librational disturbances. Such a global approach-formulation numerical code, dynamics, and control-is indeed rare. It can serve as a powerful tool to gain comprehensive understanding of dynamical interactions and thus aid in the development of an effective and efficient control system     

Channelization: the two-fault tolerant attitude control functionfor the Space Station Freedom

The Space Station Freedom was, from the mid-1980's through 1993, the design for an international orbiting laboratory facility. The Space Station Freedom was comprised of “utility” systems, such as power generation and distribution, thermal management, and data processing, and “user” systems such as communication and tracking, propulsion, payload support, and guidance, navigation, and control. These systems are required to work together to provide various station functions. To protect the lives onboard and the investment in the station, the systems and their connectivity had to be designed to continue to support critical functions after any single fault for early assembly stages, and after any two faults for later stages. Of these critical functions, attitude control was the most global, incorporating equipment from nearly all major systems. The challenge was to develop an architecture, or integration, of these systems that would achieve the specified level of fault tolerant attitude control and operate, autonomously, for the three-month unmanned periods during the assembly process. Additionally, this architecture had to maintain the desired utility of the station for each stage of the assembly process. This paper discusses the approach developed for integrating the systems such that the fault tolerance requirements were met for all stages of assembly. Some of the key integration issues are examined and the role of analysis tools are described. The resultant design was a highly channelized one, and the reasons and the benefits of this design will be explored. The final design was accepted by the Space Station Control Board as the design baseline in July 1992     

International Space Station power storage upgrade planned

As the Earth-orbit International Space Station (ISS) grows, it needs more power which is generated by solar panels. For periods in which the planet Earth occults sunlight, energy is stored in the biggest set of batteries ever flown in space. Reliability of power is important in a space station because a failure requires costly launch of replacement components. Even greater importance results when astronauts work in the station. A power failure that causes the astronauts to perish would be a very serious event. The first battery-containing "integrated equipment module" was launched November 30, 2000 and installed on port 6 of the International Space Station. Two more modules will be launched by the United States; to be launched in 2004 is the European Space Agency's "attached COLUMBUS APM laboratory," which will have its own power system. Unexpected battery-related events occurred in the integrated equipment module during its first year-and-a-half in orbit. The problems and their solutions were described in papers presented at the 37/sup th/ Intersociety Energy Conversion Engineering Conference. Since the International Space Station carries more battery cells than any other spacecraft, the in-flight performance data from its battery assembly can be useful to engineers who design power supplies for other spacecraft. We, therefore, summarize the battery development process, the adopted design, and an unexpected in-flight battery degradation and its correction.     

Optimization of the tether-assisted return mission of a guided re-entry capsule

This paper presents the mission analysis of a tether-assisted payload retrieval from the International Space Station (ISS). The objective is to assess all relevant phases of such a mission in order to allow a comparison with a conventional mission employing a propulsive deorbitation. The controlled tether deployment procedure and the guided return flight of the released re-entry capsule are optimized. A preferable deployment strategy is identified that allows for favorable entry conditions and low flight loads. The optimal deployment trajectories serve as a basis for an optimal dynamic regulator. This approach is extended towards an adaptive concept, where artificial neural networks are applied to deployment control. For the guidance of the capsule a predictive concept is proposed that is based on the optimal re-entry trajectories identified previously. By applying these concepts, the attainable landing accuracy during return amounts to an average of 5 km, and the application of the tether system exhibits overall system mass advantages. This demonstrates that the tether-assisted return mission is a competitive alternative.     

An advanced flight control and navigation system implementation fortactical helicopters

US Army helicopters that will allow single-crewmember operability in tactical environments require a high degree of automation. A tightly integrated flight control and navigation system has been studied. An architecture is discussed which meets anticipated flight control and navigation requirements, at an acceptable weight, using techniques of functional and physical integration. The architecture maximizes the sharing of sensor and computational resources in a flight critical environment and uses modular equipment packaging, dual fault-tolerant tetrad ring-laser-gyro inertial measurement units, and triplex self-checking processor pair-based flight critical processing channels     

多电飞机作动系统的体系结构优化(英文)

多电技术的深入发展使得飞机上可选择的功率源和作动器种类越来越多,这导致在机载作动系统体系结构优化设计过程中出现了不同功率源和作动器组合的极端复杂性,传统的"试凑"法已无法完成设计任务。首先介绍了多电飞机飞控作动系统(Flight Control Actuation System,FCAS)的组成,计算了其可能的体系结构数量;其次提出了FCAS体系结构在安全性、重量和效率方面的评价指标,计算了全机各舵面均采用同类作动器时的评价指标值;最后对比分析了现有的各种多目标优化算法,采用遗传算法给出了多电飞机FCAS体系结构的多目标优化设计结果。对比传统的只采用阀控液压伺服作动器的作动系统体系结构,优化后的体系结构可以在满足安全可靠性要求的前提下使系统的重量减轻6%左右,效率提高30%左右。     

The Japanese Experiment Module

This paper describes Japanese Experiment Module (JEM) which is a Japanese contribution to International Space Station (SS) Program. First half of phase B study of JEM was completed last March successfully. JEM primary function and basic configuration has been established. JEM consists of a Pressurized Module (PM), an Exposed Facility (EF), a scientific/equipment airlock, a local remote manipulator, and an Experimental Logistic Module (ELM). With all those hardware elements, JEM will accommodate general scientific and technology development research (some of which are to utilize the advantage of microgravity environment), and also accommodate control panels for the Space Station Mobile Remote Manipulator System and attached payloads.     

Space, security in the forefront

The Washington Watch column reports on President Bush's recently announced human space flight program, which includes new policies for returning the shuttle to flight, finishing the International Space Station by 2010, and developing a new space vehicle to return to the Moon; challenges in the airline industry; and selection of a helicopter for use by the President.     

James Webb Space Telescope: Project Overview

The James Webb Space Telescope (JWST) project at the NASA, Goddard Space Flight Center (GSFC) is responsible for the development, launch, flight, and science operations for the telescope. The project is in phase B with its launch scheduled for no earlier than June 2013. The project is a partnership among NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The JWST mission team is fully in place, including major ESA and CSA subcontractors. This provides an overview of the planned JWST science, current architecture focusing on the instrumentation, and mission status, including technology developments, and risks.     

Design of the Space Station Freedom power system

The design of Space Station Freedom's electric power system (EPS) is reviewed, highlighting the key design goals of performance, low cost, reliability, and safety. The EPS design is divided into three separate areas: power generation and storage, power distribution, and power management and control. Both photovoltaic and solar dynamic power generation and storage systems are used. Tradeoff study results that illustrate the competing factors responsible for many of the more important design decisions are discussed. Reliability and maintainability, as well as verification and testing, are addressed     

Bumpy ride back to space

Plans for U.S. return to the International Space Station via STS-114 are described with emphasis on safety of flight hardware and safety of the space station and the space shuttle.     

Engineering test beds on the International Space Station

The International Space Station is a unique multi-faceted orbiting laboratory supporting research, development, test and evaluation of new innovative space and Earth-based applications. While NASA sponsored investigations on the ISS are focused largely on enabling future long duration human space exploration missions, Congress designated the US portion of the space station as a National Laboratory making its facilities available to other Federal agencies and private entities for non-exploration related ventures. RDT&E activities on the ISS encompass a number of technical areas including environmental control and life support, communications, materials science, guidance, navigation and control, propulsion, electrical power, and thermal control systems.