Figure 1. The facility emulator screen
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.
Nominal-operations courseware
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
tool
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:
Web-Based Training
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.
Multi-platform capabilities
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.
Interactive environment
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).
Performance control
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:
Limited bandwidth
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.
Security
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
reference material)
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
information
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
interface
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
information
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
operational environment
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:
Experiment execution
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
Figure 8. Trouble-shooting session
Main experiment features
Web-Based
Training
The information used in the experiment is
provided by a Web server and accessed and displayed by a Web
browser. All the elements have been developed using Web
technologies (HTML, Javascript, CGI). However, in the on-board
environment, the experiment itself is not integrated on a
computer network (server and browser are in the same machine)
because of the station's limited resources in terms of available
computers and ground connections.
Modularity
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)
Experiment development
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.
Trouble-shooting implementation
The 'trouble-
shooting engine' is a piece of software completely programmed in
Javascript (object-based scripting language embedded in a HTML
page), and takes advantage of the new features present in its
latest version (included in Netscape 3.0). It performs the
following tasks:
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.
ESA Bulletin Nr. 89.