The cost benefits of the Spacelab system to scientific investigations and space applications

In the past, one of the major problems in performing scientific investigations in space has been the high cost of developing, integrating, and transporting scientific experiments into space. The limited resources of unmanned spacecraft, coupled with the requirements for completely automated operations, was another factor contributing to the high costs of scientific research in space. In previous space missions after developing, integrating and transporting costly experiments into space and obtaining successful data, the experiment facility and spacecraft have been lost forever, because they could not be returned to earth. The objective of this paper is to present how the utilization of the Spacelab System will result in cost benefits to the scientific community, and significantly reduce the cost of space operations from previous space programs.The following approach was used to quantify the cost benefits of using the Spacelab System to greatly reduce the operational costs of scientific research in space. An analysis was made of the series of activities required to combine individual scientific experiments into an integrated payload that is compatible with the Space Transportation System (STS). These activities, including Shuttle and Spacelab integration, communications and data processing, launch support requirements, and flight operations were analyzed to indicate how this new space system, when compared with previous space systems, will reduce the cost of space research. It will be shown that utilization of the Spacelab modular design, standard payload interfaces, optional Mission Dependent Equipment (MDE), and standard services, such as the Experiment Computer Operating System (ECOS), allow the user many more services than previous programs, at significantly lower costs. In addition, the missions will also be analyzed to relate their cost benefit contributions to space scientific research.The analytical tools that are being developed at MSFC in the form of computer programs that can rapidly analyze experiment to Spacelab interfaces will be discussed to show how these tools allow the Spacelab integrator to economically establish the payload compatibility of a Spacelab mission.The information used in this paper has been assimilated from the actual experience gained in integrating over 50 highly complex, scientific experiments that will fly on the Spacelab first and second missions. In addition, this paper described the work being done at the Marshall Space Flight Center (MSFC) to define the analytical integration tools and techniques required to economically and efficiently integrate a wide variety of Spacelab payloads and missions. The conclusions reached in this study are based on the actual experience gained at MSFC in its roles of Spacelab integration and mission managers for the first three Spacelab missions. The results of this paper will clearly show that the cost benefits of the Spacelab system will greatly reduce the costs and increase the opportunities for scientific investigation from space.     

Using Spacelab as a precursor of science operations for the Space Station

For more than 15 years, Spacelab, has provided a laboratory in space for an international array of experiments, facilities, and experimenters. In addition to continuing this important work, Spacelab is now serving as a crucial stepping-stone to the improved science, improved operations, and rapid access to space that will characterize International Space Station. In the Space Station era, science operations will depend primarily on distributed/remote operations that will allow investigators to direct science activities from their universities, facilities, or home bases. Spacelab missions are a crucial part of preparing for these activities, having been used to test, prove, and refine remote operations over several missions. The knowledge gained from preparing these Missions is also playing a crucial role in reducing the time required to put an experiment into orbit, from revolutionizing the processes involved to testing the hardware needed for these more advanced operations. This paper discusses the role of the Spacelab program and the NASA Marshall Space Flight Center- (MSFC-) managed missions in developing and refining remote operations, new hardware and facilities for use on Space Station, and procedures that dramatically reduce preparation time for flight.     

Space platforms: A cost effective evolution of Spacelab operation

The Shuttle/Spacelab mode of space operations will soon provide ready access to space for a wide varity of experimenters. When the full capabilities of this system are utilized, an important tool will have been added to the research and development phases of the various disciplines. Although significant benefits can now be envisioned from using these systems, it has become evident that additional benefits to the users could be achieved if some of the available resources were augmented. Those resources include: power, thermal control; duration on orbit; stability; and orientation.This paper reports planning efforts in progress to determine what augmentation these systems should provide. To properly bound the study effort, a projection of the potential Spacelab activity through the 1980 decade is developed. Three major augmentation systems are examined and the benefits provided by each are outlined. One of these systems, the Science and Applications Space Platform, represents a very attractive concept and the potential cost effectiveness is examined in detail. After these analyses are completed, general conclusions on the cost and other benefits of Space Platforms are provided.     

The deep space 1 extended mission

The primary mission of Deep Space 1 (DS1), the first flight of the New Millennium program, completed successfully in September 1999, having exceeded its objectives of testing new, high-risk technologies important for future space and Earth science missions. DS1 is now in its extended mission, with plans to take advantage of the advanced technologies, including solar electric propulsion, to conduct an encounter with comet 19P/Borrelly in September 2001. During the extended mission, the spacecraft's commercial star tracker failed; this critical loss prevented the spacecraft from achieving three-axis attitude control or knowledge. A two-phase approach to recovering the mission was undertaken. The first involved devising a new method of pointing the high-gain antenna to Earth using the radio signal received at the Deep Space Network as an indicator of spacecraft attitude. The second was the development of new flight software that allowed the spacecraft to return to three-axis operation without substantial ground assistance. The principal new feature of this software is the use of the science camera as an attitude sensor. The differences between the science camera and the star tracker have important implications not only for the design of the new software but also for the methods of operating the spacecraft and conducting the mission. The ambitious rescue was fully successful, and the extended mission is back on track.     

Shuttle-era experiments in the area of plasma flow interactions with bodies in space

A new experimental approach is discussed in general terms, that can be adopted in the Shuttle/Spacelab era starting in the 1980s for studies in the area of plasma flow interactions with bodies in space. The potential use of the Space Shuttle/Orbiter as a near Earth plasma laboratory for studies in the area of Space Plasma Physics and particularly in the area of Solar-System Plasmas is discussed. This new experimental approach holds great promise for studies in the Supersonic and sub-Alfvenic flow regime which has applications to the motion of natural satellites around their mother planets in the Solar-system (e.g. the satellite Io around the planet Jupiter). A well conceived experimental and theoretical program, can lead to a better physical understanding regarding the validity and range of applicability of using gas-dynamic, kinetic and fluid approaches in describing collisionless plasma flow interactions with bodies in a variety of flow regimes.In addition to the above scientific aspects of the program, significant technological advances can be achieved regarding the interaction of space probes in planetary atmospheres/ionospheres and the reliability of using various plasma diagnostic devices on board spacecraft and large space platforms.     

Potential cost reductions for three STS/Spacelab mission modes

Based on the results of studies carried out by ESA several possibilities are discussed to achieve mission cost reductions for large Spacelab instrument facilities as compared to their flight on several 7-day duration Spacelab missions. As an example three scientific telescope facilities are selected (LIRTS, EXSPOS, GRIST) which are defined to a Phase A level.Three new mission modes are considered:

• —Shuttle attached Spacelab mission mode with extended flight duration (up to 30 days) for which the application of planned capability extensions and new elements of the STS/Spacelab (e.g. Short Spacelab Pallets, Power Extension Package) are investigated.

• —Shuttle deployed mission mode, for which the telescope, accommodated on a Spacelab pallet, is docked to the Power Module, a new element of the Space Transportation System under study by NASA.

• —Free-flying mission mode, for which Shuttle launched dedicated missions of the facilities are considered, assuming varying degrees of autonomy with respect to supporting services of the Shuttle.

Reduction of costs have been considered on the levels of single mission cost and total programme cost. Fundamentally the charges for the instrument can be reduced by constraining the mass/volume factors with respect to the Shuttle capability. However, the instrument as part of a payload is only viable if an acceptable resource sharing including observation time can be achieved. Any single instrument will require several mission opportunities or one mission which achieves a similar or longer total observation programme.Based on an identification of instrument modifications of the Phase A baseline designs to favour cost reductions and on a derivation of technical requirements, constraints and finally budgetary cost comparisons an attempt is made to assess the advantages and disadvantages of the different mission modes.The favoured option for GRIST is a 2–3 weeks sortie mission followed after refurbishment by a longer Power Module docked mission. For LIRTS and EXSPOS the free-flying pallet modes are very attractive in terms of the longer durations achieved and in terms of cost per unit operating time.     

Micro- and mini-satellites of ISRO—technology and applications

With rich experience of the successful Indian remote sensing satellite series, Indian Space Research Organization (ISRO) has started theme-based satellites like Resourcesat and Oceansat. Further taking the advantage of the improved technologies in areas of miniaturization, the micro- and mini-satellite series have been started, which will provide opportunity for the payloads of stand-alone missions, for applications, study or research. These include payloads for Earth imaging, atmospheric monitoring, ocean monitoring, scientific applications, and stellar observation. The micro-satellites are of 100 kg class, planned with a payload of about 30 kg and 20 W power and mini-satellites of 450 kg class for payloads of 200 kg and power of 200 W. The first satellite in the micro-satellite series is an Earth imaging payload followed by the second satellite with scientific payloads with the participation of students. Further the scientific proposals for micro-satellites are under evaluation. Similarly the first two missions of mini-satellites are defined with first one carrying ocean and environment monitoring payloads followed by the Earth imaging satellite with multi-spectral camera with 700 km swath. The current paper touches upon the technology involved in realization of the micro- and mini-satellites and the scope of applications of the series.     

European materials science investigations and associated experimental equipment within the Spacelab demonstration missions

This paper reviews shortly the results obtained by a preliminary call for experiment proposals for future Spacelab flights issued by the European Space Agency in April 1978. The results of this call indicate clearly the trend towards experiments performing studies on the state and the evolution of fluid media. The instrumentation used are mainly multipurpose instruments (furnaces, process chambers) already under development for the first Spacelab flight and new equipment currently under study.     

The future of human spaceflight.

After the Apollo Moon program, the international space station represents a further milestone of humankind in space, International follow-on programs like a manned return to the Moon and a first manned Mars Mission can be considered as the next logical step. More and more attention is also paid to the topic of future space tourism in Earth orbit, which is currently under investigation in the USA, Japan and Europe due to its multibillion dollar market potential and high acceptance in society. The wide variety of experience, gained within the space station program, should be used in order to achieve time and cost savings for future manned programs. Different strategies and roadmaps are investigated for space tourism and human missions to the Moon and Mars, based on a comprehensive systems analysis approach. By using DLR's software tool FAST (Fast Assessment of Space Technologies), different scenarios will be defined, optimised and finally evaluated with respect to mission architecture, required technologies, total costs and program duration. This includes trajectory analysis, spacecraft design on subsystem level, operations and life cycle cost analysis. For space tourism, an expected evolutionary roadmap will be described which is initiated by short suborbital tourism and ends with visionary designs like the Space Hotel Berlin and the Space Hotel Europe concept. Furthermore the potential space tourism market, its economic meaning as well as the expected range of the costs of a space ticket (e.g. $50,000 for a suborbital flight) will be analysed and quantified. For human missions to the Moon and Mars, an international 20 year program for the first decades of the next millennium is proposed, which requires about $2.5 Billion per year for a manned return to the Moon program and about $2.6 Billion per year for the first 3 manned Mars missions. This is about the annual budget, which is currently spend by the USA only for the operations of its Space Shuttle fleet which generally proofs the affordability of such ambitious programs after the build-up of the International Space Station, when corresponding budget might become again available.     

Cost effectiveness of Spacelab experiments

Spacelab permits investigation in new seicntific disciplines like material processing, life sciences, chemistry, etc. The large mass and volume capabilities of Spacelab offer better possibilities for some areas of traditional space sciences like infrared astronomy, multi-spectral solar observations and large instruments for astronomical observations.Since free-flyers will require normally a new spacecraft development for each mission, the reusability of space qualified components and experiments will be a significant cost reduction factor over a long period. In the early phase of Spacelab utilisation, however, the scaling factor introduced by Spacelab utilisation, however, the scaling factor introduced by Spacelab results in higher payload development costs than originally appreciated.The costs of Spacelab utilisation are computed and compared with those of conventional free-flying satellites. The mission implementation costs and experiment development costs are shown for both cases. The Spacelab mission implementation costs are subdivided into NASA charges for the Standard Shuttle Mission, NASA charges to fly and operate Spacelab, the European costs of Spacelab payload integration and experiment development costs. In order to evaluate and compare mission implementation costs, the simple parameters are adopted of the cost per kg of experiments and the data collection-transmission capability of Shuttle/Spacelab and ESRO/ESA satellites. The mission implementation costs turn out to be very favourable for Spacelab. The experiment development costs, which are not included in the mission implementation costs, are compared for several free flyers with the corresponding development costs for several experiments of the first Spacelab payload. The comparison shows that the cost per kg of Spacelab experiment development is about five times less than of satellite experiments.     

The capture-cell experiment for the first LDEF mission

The Long Duration Exposure Facility (LDEF) is an experiment carrying structure, which will be transported into a near earth orbit by the Space Transportation System of the U.S.A., where it will remain for approx, one year and then be brought back to Earth. A group of experiments investigates the cosmic dust environment. This paper describes the principle of a micro-meteoroid capture-cell experiment which has been accepted for the first LDEF flight in 1984. The development of the components and the tests conducted with the prototype are discussed together with the analysis of the simulation results using a secondary ion mass spectrometer (SIMS).     

Use of pallet-type structures in Shuttle-attached and free-flying modes

Modular pallet-type structures, designed for optimal usage of the Space Shuttle as a launch vehicle, can be used in three mission modes—Shuttle-attached, attached to an orbiting Power Module, or as fully autonomous free flyers. The requirements for such structures are defined and three structural solutions—the Spacelab pallet, a cubic framework structure and a honeycomb panel structure—are described. System and subsystem concepts of varying complexity and autonomy are indicated and their applications to several typical payload examples are shown.     

The Kinelite Project: a new powerful motion analyser for Spacelab and space station

The goal of the Kinelite Project is to develop a space qualified motion analysis system to be used in space by the scientific community, mainly to support neuroscience protocols. The measurement principle of the Kinelite is to determine, by triangulation mean, the 3D position of small, lightweight, reflective markers positioned at the different points of interest. The scene is illuminated by Infra Red flashes and the reflected light is acquired by up to 8 precalibrated and synchronized CCD cameras. The main characteristics of the system are: Camera field of view: 45 degrees; Number of cameras: 2 to 8; Acquisition frequency: 25, 50, 100, or 200 Hz; CCD format: 256 x 256; Number of markers: up to 64; 3D accuracy: 2mm; Main dimensions: 45 cm x 45 cm x 30 cm; Mass: 23 kg; Power consumption: less than 200 W. The Kinelite will first fly aboard the NASA Spacelab; it will be used, during the NEUROLAB mission (4/98), to support the "Frames of References and Internal Models" (Principal Investigator: Pr. A. Berthoz, Co Investigators: J. McIntyre, F. Lacquaniti).     

The International Space Station: a pathway to the future

Nearly six years after the launch of the first International Space Station element, and four years after its initial occupation, the United States and our 6 international partners have made great strides in operating this impressive Earth orbiting research facility. This past year we have done so in the face of the adversity of operating without the benefit of the Space Shuttle. In his January 14, 2004, speech announcing a new vision for America's space program, President Bush affirmed the United States' commitment to completing construction of the International Space Station by 2010. The President also stated that we would focus our future research aboard the Station on the long-term effects of space travel on human biology. This research will help enable human crews to venture through the vast voids of space for months at a time. In addition, ISS affords a unique opportunity to serve as an engineering test bed for hardware and operations critical to the exploration tasks. NASA looks forward to working with our partners on International Space Station research that will help open up new pathways for future exploration and discovery beyond low Earth orbit. This paper provides an overview of the International Space Station Program focusing on a review of the events of the past year, as well as plans for next year and the future.     

European response to the NASA space station initiative

This article contrasts the political motivations behind the US space station initiative with those underlying the European Space Agency's Long Term Plan. Philip Chandler concludes that European cooperation in NASA's space station programme (SSP) will serve three needs: to buy time; to allow European users to undertake longer, manned experiments; and, to keep the Spacelab teams intact. However, in itself the SSP holds little value for Europe.     

高速摄像技术在火箭橇头罩分离试验中的应用

火箭橇头罩分离试验中,需要采集头罩分离前后的高速图像。由于火工品爆炸时间短,振动与冲击环境恶劣,普通摄像设备难以满足要求。文章介绍了一种小型化、低功耗、能够适应强振动与冲击环境的高速摄像系统,该系统由具有Camera Link接口的工业相机、图像采编单元和数据存储单元组成,图像采编单元对工业相机图像数据进行编码,并通过LVDS接口传输至数据存储单元;数据存储单元使用FPGA控制SATA接口固态硬盘实现无损图像数据的实时存储。通过减振和自动调光设计,此系统能够适应强振动与冲击环境,并能自动快速适应各种光照环境,已成功应用在某火箭橇头罩分离试验中,实现了分辨率为800×600、帧率为120帧/s的连续图像存储,存储时间不低于30 min,存储的图像数据完整可靠。     

空间红外望远镜(SIRTF)

文章介绍了空间红外望远镜装置SIRTF(SpaceInfraredTelescopeFacility)的用途 ,详细介绍了SIRTF上携带的低温望远镜装置CTA(CryogenicTelescopeAssembly)和 3台成像仪器 :红外阵列相机IRAC(In fraredArrayCamera)、红外光谱仪IRS(InfraredSpectrogram)和多谱段成像分光计MIPS(MultibandImagingPho tometerforSIRTF)。     

A parametric study of space transfer/upper propulsion stages

For Space Transportation System (i.e. Space Shuttle) launched satellites destined for a Geosynchronous Earth Orbit (GEO), there is a need for cost-effective, versatile propulsion systems to provide the perigee burn, i.e. to boost the satellite from Low Earth Orbit (LEO) to Geosynchronous Transfer Orbit (GTO). Surveys of commercial spacecraft activities and future GEO satellite requirements indicate that a spacecraft propulsion system that will provide the perigee burn for a broad range of future commercial satellites would have an excellent market potential.Parametric studies to investigate and define attractive perigee-burn upper propulsion systems (i.e. an Upper Propulsion Stage, or a UPS) are presented. The feasibility and payload capacilities that could be provided by a UPS assembled from essentially off-the-shelf components and subsystems, and the benefits that could be achieved by using major subsystems specifically tailored for the application are presented. The results indicate that attractive UPS configurations can be defined using either off-the-shelf or optimized major subsystems.