In preparing for the operation of the International Space Station (ISS), new approaches to astronaut on-board training are being considered. Emerging computer technologies like multi-media (usage of graphics, photographs, animation, sound and motion video) and the World Wide Web, together with the use of equipment simulators and the innovative application of instructional methodologies, are key elements in these new developments.
Mir 97, the 20-day German mission to the Russian space station Mir, scheduled for February 1997, is to be the test-bed for the Modular On-board Training Environment (MOTE), a series of experiments comprising an integrated training system that includes: a nominal-mission training lesson, a facility simulator, a non-nominal-mission training lesson, and a failure- diagnosis system. The facility chosen for these training elements is the TITUS furnace, designed for conducting material-science experiments aboard Mir.
MOTE is the result of the integration of three originally self- standing elements:
Figure 1. The facility emulator screen
TITUS furnace emulator
This is a high- fidelity simulation of the TITUS furnace, which receives commands from the facility-control software (TITAN, developed by DLR's Microgravity User Support Centre in Cologne, Germany) and generates responses and experiment data just like the real facility. The emulation provides a point-and-click interface to allow the astronauts to visualise, navigate around and interact with the furnace's exterior and interior. Using this emulation environment, the astronaut can perform the furnace procedures for the electrical installation and run the experiments. This includes such mechanical operations as connecting cables, installing experiment probes, opening and closing hatches, and actuating switches.
The emulator was developed by VEGA Space Systems Engineering GmbH, located in Darmstadt, Germany.
This element trains the astronaut to perform nominal operations on the TITUS furnace, e.g. starting and shutting down the facility, loading and removing samples, loading an experiment run, starting the run and monitoring its progress. Much of the courseware is orientated towards the facility-control software. During the course of the experiment, some of the training material will be uploaded from the ground using Web technology.
Figure 2. Nominal-operations courseware screen
The experiment was developed by the German Aerospace Research Establishment (DLR), located in Cologne, Germany.
Non-nominal-operations courseware and trouble-shooting
This courseware and trouble-shooting tool is used by the astronauts to identify the causes of failures in the TITUS furnace and to train in how to resolve them. It also provides instructions for a previously untrained-for maintenance activity on the furnace (tube heater cleaning operation).
Figure 3. Non-nominal-operations courseware screen
This tool has been developed by EAC itself.
Whilst the above-described experiments will be performed in three separate sessions on-board (see below), their integration allows each of the components to make use of the other two. This interaction between components is illustrated in Figure 4.
Figure 4. MOTE system components
The MOTE system, which runs under the Windows NT 3.51 operating system on the Mir 97 laptop (a 75 MHz 486 with 32 MB of RAM), contains the following software components:
Computer-Based Training (CBT: training delivered on a computer) is rapidly taking advantage of all of the emerging technologies in the form of Web-Based Training (WBT), an innovative approach in which the WWW is the vehicle for delivering training. An increasing number of organisations, universities and industrial corporations have already chosen WBT to implement their training strategy due to its many advantages, which can be summarised as follows:
Time- and place-independence
Users can access the training system whenever and wherever they want. A team of trainees can be brought together from around the globe, and/or instructors can coordinate instruction with colleagues from other locations. All of this provides a new scenario for collaborative training which is difficult to implement using instructional settings other than WBT.
The WWW (or Web, for short) is a wide-area client/server architecture for exchanging hypermedia information across the Internet network. In this distributed environment, the information is transferred between Web servers (information providers that store and distribute WWW documents) and Web browsers (client applications such as Netscape(sup TM) or Mosaic(sup TM) that retrieve and display these data).
Web pages (WWW documents) are formatted in HTML (HyperText Markup Language), which consists of a set of tags to create hypermedia documents i.e. multimedia pages containingtext, graphics, sound and video, that include hyperlinks (clickable areas on the screen linking to other documents).
Figure 5 shows an example of the interaction between Web servers and browsers. A user in Computer-A accesses a Web page which is served by Computer-B. The loaded Web page can contain hyperlinks to other pages that may be in the same Web server or anywhere else on the Internet. 'Navigating' through the WWW, information is accessed in a non-linear way, unlike 'traditional' book-like documents where the text must be read sequentially (from top to bottom).
Figure 5. Example of the interaction between Web servers and Web browsers
Figure 6. Example scenario for WBT
A special feature of the WWW is that it is a heterogeneous, flexible environment; i.e.
Evolution of WWW
Since its birth in the late 1980s at CERN (European Centre for Nuclear Research), the WWW has become tremendously popular and has evolved quickly, adopting new technologies along the way. The most significant ones include:
MOTE uses this feature to run SHAPE as an external (helper) application when an emulation script is received by the Web browser.
In MOTE, a CGI Perl script stores information that the browser sends to the server (questionnaire responses).
The lesson and trouble-shooting engines used in MOTE make use of this technology.
The WWW is platform-independent by nature in that the browsers are developed for the different platforms but making use of the same data formats and protocols. Users at different locations can be using different systems (operating systems, computers) without affecting training efficiency and performance.
Easy updating of instructional material
Updating Web-based instructional material (Web pages) is easier and quicker - and therefore cheaper - than other kinds of delivery support (e.g. CD-ROM). On-line access minimises redundancy of information, in that the lesson contents are stored on a reduced number of Web servers, and consequently also the effort spent on updating.
A good application of multi-media and instructional methodologies results in highly interactive user interfaces that enhance training efficiency. A networked environment adds the possibility of interaction between users (instructor - trainee, trainee- trainee , and instructor-instructor).
Web technologies allow the immediate monitoring of trainees' activity (logging access, training-session performance, test evaluation). This can only increase feedback and improve the quality of training.
Use of existing tools
An Internet-based environment such as WBT provides a number of utilities that complement the training activity, including: use of e-mail, BBS (Bulletin Board Systems) or WWW itself to search for additional information, and real-time conferencing (text or video based).
On the other hand, the current state of development of such a new technology also has disadvantages:
A growing number of WWW users, the use of memory-intensive data (sound, motion video, sophisticated graphics), and the limited bandwidth of the Internet connections results in slower performance. For this reason, today's Computer-Based Training platforms that require high multi-media capabilities are based on stand-alone platforms and CD-ROM media delivery. Meanwhile WBT developers are combining techniques like data compression, efficient Web page design, and server/client-side programming to cope with this limitation.
Advances in computer network technology and improved bandwidth will result in capabilities for better multi-media access. Already available WWW-based features like 3D virtual reality, animations, conferencing, and real-time audio and video will be powered with these improvements.
In this direction, the Internet-II project (a recent agreement between several US universities, supported by the US government and industry) will be developed to exploit the capacity of broadband networks to support multi-media communications, real- time collaboration, and other functions that can advance distance education. The network is expected to be developed over the next 3 to 5 years.
Being a worldwide public network, the Internet allows the sharing of information among users distributed around the world. This feature can also be seen as a disadvantage when the information must be protected against misuse and unauthorised access.
The use of Intranets (private networks contained within an enterprise using Internet protocols) is common among organisations which want their information secured against external intruders. Large enterprises allow connection beyond the Intranet to the Internet through firewalls (servers that have the ability to screen messages in both directions so that company security is maintained). Another safety strategy is the use of 'tunnelling' protocols that allow the creation of a secure network through 'tunnels' over the public Internet.
Poor authoring environments
Today's authoring environments for WBT are currently far less evolved than those provided for multimedia CBT, but this is changing very rapidly. Authoring software for WBT is currently following two approaches:
We will now move on to analyse some of the special requirements imposed by the new International Space Station (ISS) distributed and on-board training scenarios, and then show how Computer-Based Training, and in particular Web-Based Training, are well-suited to meeting these requirements.
The International Space Station (ISS) Programme is a joint effort involving five international partners: NASA, RSA, ESA, NASDA and CSA. A primary purpose of the Station is to provide a permanent low Earth orbit research facility with which to perform microgravity experiments in a variety of disciplines: life sciences, materials science, technology, etc.
During the Station's planned operational lifetime of some 15 years, its on-board science facilities will be used continuously in orbit by scientists and astronauts for long periods of time. It will also be the focus of activity for thousands of researchers across the world who will monitor and operate experiments from the ground.
Thus, the personnel involved in ISS training activities span a wide range of cultures, locations and individuals: astronauts (payload specialists, mission specialists), ground-based scientists and ground support personnel must know how to perform the experiments for a particular mission and be familiar with the on-board and on-ground facilities. The training materials required to achieve this can include simulators and Computer- Based Training that will be used at different locations around the world many times. The multi-national nature of the ISS means that the different individuals involved in training (subject- matter experts, scientists, instructors, astronauts) and the training material can be located in different countries.
WBT appears to be an ideal training instrument in such a distributed environment.
Once fully operational, the ISS will host from three to six people at a time, a typical astronaut mission lasting from 3 to 5 months in orbit. In this scenario, crew members will combine station maintenance tasks with the development of research activities, and will eventually have to deal with non-nominal situations (due to unexpected experiment results, changing environments or facility malfunctions with different potential hazard levels).
Although most on-board activities will be the subject of pre- flight training, On-Board Training will still play a key role in many cases:
WBT is especially well-suited for implementing certain types of on-board training proficiency training, refresher training, training on non- nominal situations and malfunctions benefiting from both CBT and Web technologies. To justify this claim, we must address key requirements that the ISS framework will present:
Req. 1: Flexibility (easy updating of training and
The available computer-based material developed to train ISS crew members will evolve continuously as more experience is gained in the use of the Station. New lessons (nominal and non-nominal) will be identified and developed continuously and existing lessons will be subject to revision. The same logic can be applied to systems and pay- load reference information. In a Web-based environment, this updating is immediate.
Req. 2: On-ground/on-board common
The sharing of information between ground-based personnel and crew members not only avoids data inconsistencies and facilitates updating, but also improves communication between the different users. Assistance during training is optimised when both the instructor and the trainees have exactly the same information on the screen. The same situation occurs when using any kind of software application that may require supervision or support from a remote expert.
Req. 3: On-ground/on-board common user
OBT is best achieved when the trainee is already familiar with the training environment. WBT has been presented in this context as a suitable element with which to train ISS on-ground personnel (including astronaut pre-flight training). Its extension to on-board training means that crew members will not need to adapt to a new training environment.
Req. 4: Access to ground-based scientific
Accessing ground-based scientific material and communication with ground-based scientists will be common requirements for ISS crew members. The WWW provides an integrated environment in which the world-wide scientific community can communicate and share information (e-mail, file transfer, Web access).
Req. 5: Integration of training with on-board
WWW applications are already present on millions of computer desktops distributed around the world. The computer industry is evolving very quickly towards an integrated platform where all software applications are structured on a WWW foundation. Training and operational support tools are no exception and their level of integration with the WWW will increase in the coming years.
Req. 6: Platform independence
The worldwide community that is contributing (and will contribute) to the ISS project is a very heterogeneous one. Taking advantage of its inherent multi-platform capabilities, the WWW allows users to design, develop and deliver training regardless of the operating system or computer used.
Req. 7: High level of security
The operationally controlled environment of a Space Station requires a high level of access and security control that MUST be enforced. A great deal of effort has to be devoted in order to foresee controlled, monitored updating of onboard electronic information. Whilst this implies an additional effort in the development phase, it will guarantee that information exchanges with the Station are free from the hazards of unforeseen and unplanned communication.
Web-Based Training, despite its current limitations (Internet's limited bandwidth presently being the most prevalent), meets the requirements presented above, making it a very valuable candidate for both ISS on-ground and on-board training.
One of the European Astronauts Centre's contributions to the Mir 97 mission is an on-board training experiment consisting of a non- nominal-operations lesson and a trouble-shooting tool, as mentioned earlier in this article. The goals that led to the development of this experiment were:
The software will be uploaded to Mir via Soyuz TM-25 at the start of the Mir 97 mission. The experiment itself is scheduled for flight day 10 and has five phases divided over two sessions: an on-board session comprising failure presentation, failure identification, presentation of failure solution and questionnaire, and a later post-flight session:
Figure 7. Failure presentation
Main experiment features
The main elements of the experiment (failure presentation, trouble-shooting and non-nominal lesson) are completely independent modules that are interconnected. The system can grow, adding new failure scenarios, and non-nominal lessons will trouble-shoot the connection between them.
Computer-Based Training standards
The non-nominal- situation lessons (two have been developed for the experiment) are designed in a modular fashion, with the instructional material (lesson pages) independent from the 'lesson engine' (lesson layout, navigation mechanism, tools), thereby facilitating updating and the creation of new lessons. The design of the lesson user interface and the lesson structure is based in current CBT guidelines (NASA standards) that have been carefully reviewed and adapted.
Figure 9. Non-nominal-operation lesson (table of contents)
Web browsers/servers employed
The experiment is based on the popular Web browser from Netscape(sup TM), taking advantage of the new features included in its latest version (3.0, released in August 1996 and available on 16 different platforms). On the server side, the EMWAC (European Microsoft Windows NT Academic Centre) HTTP server provides all of the information requested by the browser. The experiment has been developed in a networked environment and successfully tested using Netscape 3.0 for the following three platforms: Windows 3.1/95/NT, Macintosh and UNIX.
Non-nominal lesson implementation
As previously mentioned, the non-nominal lesson is based on two modules: the instructional material (lesson pages) and the lesson engine:
Figure 10. Experiment architecture N failures, 1 trouble-shoot, and M lessons
The implementation of an interface between engines and external databases will increase modularity and flexibility, allowing the trouble-shooting engine to be independent of actual symptoms, failures and estimations, and the lesson engine to be independent of lesson structure and content. It will also allow the dynamic updating of trouble- shooting and lesson elements by different users.
New elements can be added to the lesson engine to improve lesson layouts and hence training efficiency, e.g. a graphical representation of the overall lesson and the trainee's position therein at any given time.
The trouble-shooting engine can be improved by the inclusion of more 'intelligent' diagnosis methodologies (e.g. use of neural-network technology, assigning dynamic weights to symptoms or groups of symptoms when related to different failures and assigning thresholds to estimations that will only be activated when a given number of associated symptoms are selected).
Tutor support and communication between users can be upgraded by the inclusion of a type of Bulletin Board System (BBS) in the lesson environment to allow users to exchange messages at any time.
The development of an authoring environment that allows one to easily define and include new lessons and non-nominal scenarios will complement the lesson/trouble-shooting engines, allowing the system to grow with contributions from different lesson authors.
Figures 11a,b. A NASA CBT lesson page and an EAC experiment lesson page
Web-Based Training is an emerging multi- media, distributed, interactive, platform-independent technology for the preparation, delivery and implementation of training in a distributed and heterogeneous environment.
In this article, we have shown how Web technologies can be applied to a Space Station on-board facility to provide an integrated operational support environment that the astronauts and ground personnel can use cooperatively to cope effectively and efficiently with both nominal and non-nominal mission situations.
The authors would like to thank A. Pidgeon, R. Henderson and W. Peeters for their kind support during the preparation of this article.