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CDF AS A TOOL FOR SPACE ENGINEERING MASTER’S STUDENT
COLLABORATION AND CONCURRENT DESIGN LEARNING
J. Bermejo, J.M. Álvarez, P. Arcenillas, E. Roibás-Millán, J. Cubas, S. Pindado
Instituto Universitario de Microgravedad ‘Ignacio da Riva’(IDR/UPM), ETSIAE, Pza. del Cardenal Cisneros 3,
Madrid 28040, Spain. Corresponding author: J. Bermejo (juan.bermejob@alumnos.upm.es)
ABSTRACT
The IDR/UPM Institute (Instituto Universitario de
Microgravedad ‘Ignacio da Riva’) established a
Concurrent Design Facility (CDF) for space mission
design in 2011. This facility is used primarily for
academic purposes within the Master in Space Systems
(MUSE) 1
organized and managed by IDR/UPM also.
This CDF is based on the Open Concurrent Design Tool
(OCDT) from ESA, which allowed a group of students
from the master to participate in the Concurrent
Engineering Challenge organized by ESA Academy in
September 2017.
Since the early days of this facility, the development of
tools and utilities for space mission design has been
conducted by aerospace engineering students at
IDR/UPM under the direction of professors. At present,
MUSE students are programming a new set of models
for the main spacecraft subsystems, to analyze space
missions beyond Earth.
In order to make easier for MUSE students to achieve a
proper level of knowledge and experience in Concurrent
Design, a frame of cooperation has been established
between the students from the first year, who are new to
concurrent engineering, and second-year students, that
have gathered a significant level of experience in the
previous year. This cooperation enables the
comprehensive and resource-effective use of the CDF
and ensures the success in the academic skills related to
space systems engineering and mission design.
It should be also said that this cooperation between two
different year students is carried out through different
activities conducted in the CDF, involving Concurrent
Design (CD) of space missions, and working with the
available material of own creation. Through this
method, collaboration and communications skills are
improved. Additionally, Concurrent Design concepts
are more easily learnt.
In the present work the activities in relation to this
process of cooperation are described, how they fit in the
master’s academic program, and the results of the
method implementation during the academic year
2017/2018. It also includes the working methodology
employed in the CDF, developed mainly by students
and that is being improved progressively with each new
1 Master Universitario en Sistemas Espaciales
student generation.
1. INTRODUCTION
IDR/UPM Institute (Instituto Universitario de
Microgravedad “Ignacio da Riva”)2 established a
Concurrent Design Facility (CDF) in 2011, similar to
the one that ESA created in 1998 [1]. Since then,
different projects have been developed based on
Concurrent Engineering methodology. Most of them
have been conducted by collaboration between students
of the Master in Space Systems (MUSE), fully
organized by IDR/UPM [2] and conducted in Escuela
Técnica Superior de Ingeniería Aeronáutica y del
Espacio3 (ETSIAE/UPM), and IDR/UPM staff.
Although a set of academic works, including
internships, bachelor degree’s thesis dissertations and
master’s thesis dissertations, have been carried out to
develop the CDF capabilities, the evolution and
improvement of this facility is due to real engineering
projects developed together with other institutions (e.g.,
the design of the UNION Lian-Hé preliminary phases
[3]).
Among the CDF activities carried out within the last
year, the 1st ESA Concurrent Engineering Challenge
should be mentioned. In this challenge the present
authors, in collaboration with the rest of the master last
year students and supported by IDR/UPM system
engineers (Fig. 1), designed a mission whose objective
was the observation of the Moon South Pole [4].
Figure 1. MUSE professors and last year
students in CDF during ESA Challenge.
2 http://www.idr.upm.es/
3 https://www.etsiae.upm.es/
The aim of this paper is to provide a description of the
working methodology employed at IDR/UPM in the
CDF, the activities conducted by students to improve
and accelerate the learning process of Concurrent
Design (CD), the relationship between the CDF
activities and the MUSE academic program, and finally,
the results obtained in the academic year 2017/2018. It
should be also underlined that the experience from
MUSE student is included in this work, reflecting the
students’ point of view.
This paper is organized as follows. In Section 2 the
evolution of the working methodology is described. In
Section 3 the main activities carried out during the
academic year are explained. In Section 4 the results
from a MUSE student’s survey on the CDF activities
within the academic program are included. Conclusions
are summarized in Section 5.
2. WORKING METHODOLOGY
The CDF provides an environment for close interaction
among the designers and subsystem specialists. The
facility itself consists of 13 computer stations, specific
multimedia hardware for teleconferences and
presentations, a server for data storage, and a software
infrastructure for the generation of the mission design
and data propagation between disciplines in real time. It
was established in 2011 and operated with Concurrent
Design software.
At the early days of the CDF, a Concurrent Design
software was developed, using python language, by
IDR/UPM, called Concurrent Design Application [5].
At this design phase, multiple modules for the study of
different spacecraft subsystems were elaborated by
students during their internships in IDR/UPM and as
final dissertations in both, bachelor's and master's
degrees.
The main disadvantage of this approach is the
excessively amount of time required to train students
who would not continue their work next year.
Additionally, most of the modules were closed
designed and were independently developed, which
made a harsh task to integrate them together. These
modules exported their results into different formats and
used their own data base.
This software developed by IDR/UPM was substituted
in 2015 by the OCDT, a server software package
developed under an ESA contract to enable efficient
multi-disciplinary concurrent engineering of space
systems in the early life cycle phases [6].
Due to the fact that the OCDT system employs
Microsoft® Excel® as client application and that it is
widely known by bachelor students, it was decided to
develop Excel® calculation modules for the design of
spacecraft subsystems. Nevertheless, as the achievable
level of design and analysis when using Excel® is
limited, the modules are usually focused to employ an
external design software, depending on the subsystem,
to export data and import results. These modules are
similar to those developed for the SCDT4 [7].
A timeline were all these activities are described, since
the creation of the IDR/UPM Concurrent Design
Facility to the actual design methodology, is shown in
Fig. 2.
Figure 2. Timeline of IDR/UPM CDF
evolution.
2.1 Concurrent Design learning through student
collaboration
In order to transfer efficiently the acquired knowledge
by the students working in the CDF, a collaborative
frame of work between first- and second-year students
was established. This frame involves the development
or update of the available modules and also the
establishment of a learning methodology for the
continuous improvement of the CDF environment.
The collaboration among students is intended to
facilitate the learning process of concurrent engineering
and to improve their skills in terms of communication
4 Student Concurrent Design Tool
and design thinking. A group of students from
second-year organized a set of activities to train first-
year students under the direction of professors and
IDR/UPM staff.
Figure 3. CDF learning dynamic cycle.
Such activities were defined to be repeated each year
(Fig. 4), so the current first-year students will take
charge of the training of new students about Concurrent
Design and the CDF modules improvement.
3. ACTIVITIES DEVELOPED DURING
2017/2018 ACADEMIC YEAR
During 2017/2018 academic year, numerous activities
took place in the CDF and the new learning
methodology was implemented.
One of the activities developed with the CDF was the 1st
ESA Concurrent Engineering Challenge in September
2017. In this competition, the second-year students were
distributed in groups and assigned to each one of the
subsystems that conform the mission architecture.
After the competition, several students from second year
continued working in this area by developing, as Case
Study II (a mandatory subject included in the MUSE
program [8]), some of the modules that were thought to
be implemented in the CDF for future preliminary
mission designs.
In January 2018 learning sessions about the Concurrent
Design methodology in a CDF were organized. In these
sessions, second-year students taught first-year students
the main concepts and characteristics of both
Concurrent Design and the working methodology
followed in IDR/UPM CDF, including the guidelines to
develop new CDF modules. This learning sessions were
divided in two stages (Fig. 3): first, an introduction to
the Concurrent Engineering concept and the working
methodology employed in the CDF; second, the design
of a simple space mission using the available design
tools of the CDF (design modules). All the students
from first-year participated.
The first stage was conducted in one session and it was
mainly dedicated to learn the essential aspects of
concurrent engineering, which are usually unknown by
the students. This process was carried out emphasizing
the points that the present authors considered most
important and less clear according to their own
experience the previous year. It was also introduced the
working methodology applied to the CDF, particularly,
the basics of the OCDT system.
Figure 4. Activities stages description.
To reinforce the skills and enhance learning, a simple
exercise was proposed to the students. In this practice,
they were divided in pairs, with each couple dedicated
to one main spacecraft subsystem, and they were asked
to estimate the mass and power consumption of their
subsystem, based on a set of simple requirements, and
upload them to the CDF database. First design iteration
was based on simple calculations from space mission
design literature [9]. They were also required to base
their estimations taking into account the values that
other subsystems were providing. Through this simple
exercise, several main ideas of Concurrent Design were
illustrated, for example, the design loop that arises when
the propulsion subsystem needs the total spacecraft
mass as an input but it also must provide its own mass
to calculate such input.
As a final step of the first stage, the working
methodology was addressed in deep through the
presentation of a functional module developed by a
student of the second year. The students were
encouraged to interact with the module, including all the
decisions about the design options which have to be
taken, so it was possible to make easier the
understanding of the modules architecture and
functionality. This activity was intended to teach the
students the main points which have to be considered
for a module development. Thus, preparing the students
for the mission design exercise scheduled for the second
stage.
At the second stage, with the aim of perform a mission
preliminary design, the requirements were given and
translated into formal words. After that, the students
were divided again in pairs according to the same
distribution made at the first stage. During all the design
iterations, each one of the students from second year
guided several groups, solving their questions and
providing them with advices. The problems encountered
and their corresponding solutions were shared and
discussed. At the end of this activity and after fulfilling
the mission requirements, each of the student groups
elaborated a final report including the main
characteristics and the design process of their
subsystem.
In the following months, several students of first year
developed modules for specific subsystems for its
implementation in the CDF as Case Study I. During this
work, first-year students were supported by both
IDR/UPM professors and second-year students.
On account of the work carried out by all the students
involved in the CDF development, a successful set of
operative design modules was available at the end of the
academic year, each one of them comprised of some
interesting ideas based on the defined methodology.
A structure subsystem module was developed. It allows
to connect the data base from the OCDT to an industrial
design software, CATIA; after that, the module can
generate a finite element method (FEM) model in
NASTRAN©, finally reading the results and carrying
them to the OCDT again. Also, a catalogue with a list of
different Commercial off-the-shelf (COTS) elements
was collected and assembled with some of the modules,
e.g. the power subsystem module, the attitude and orbit
control subsystem module or the propulsion subsystem
module. In order to get a first step with the design
iterations, a software was programmed to generate a set
of initial values based on all the last satellite mass and
the mission purposes designed. Another idea achieved
was to connect the mission subsystem module to
GMAT©, allowing to introduce the values of the initial
and final orbits and get all the velocity increase needed.
Another developed tool implemented to the CDF was a
document management software. It allows the access to
project documents according to certain attributes given
by the user. These attributes depend on the category of
the user (basic user, subsystem responsible and project
manager) and on the different subsystems involved in a
space mission.
3.1 Future activities
In the middle of July 2018, some of MUSE students will
participate in the "2nd BUAA International Academic
Forum of Astronautical Science and Technology" at
Beihang University, China, where they will present their
work with CDF modules.
In September 2018 will take place design sessions in the
CDF with the objective of performing the preliminary
design of a CubeSat mission in L2, where modules
developed by MUSE students will be used.
4. SURVEY RESULTS
In order to evaluate the effectiveness of the learning
methodology employed, a survey about different CDF
aspects was conducted among all the MUSE students to
compare the evolution of the perception of the CDF and
the acquired knowledge. A total of 21 students
answered the questions, of whom 11 belong to the
second academic year and 10 belong to the first year.
The survey was organized into three main categories: (i)
related to the learning methodology employed, (ii)
related with the CDF utilization and (iii) related with the
CDF infrastructure. Students were asked to rate from 0
to 10 (where 10 is the highest score) the different
aspects described in Table 1.
Table 1. Survey questions organized in
three different categories: Learning
methodology, CDF utilization and CDF
infrastructure.
Learning
methodology CDF utilization CDF
infrastructure
Students
satisfaction Usefulness of
CE concept General
infrastructure
Level of
organization
Level of reality
of proposed
missions
Usefulness of
developed
subsystem
modules
Improvement
of student
skills and
capabilities
Need for
increase the
amount of CDF
desi
g
n sessions
Capability to
train next
student
generation
The survey results, represented in a 10 points scale,
where 0 represents complete disagreement and 10
complete agreement, are shown in the next figures:
Learning methodology (Fig. 5), CDF utilisation (Fig.6)
and CDF infrastructure (Fig. 7). In the graphs, the
answers from first-year students are depicted in black
and the ones from second-year students in grey. The
scoring corresponds to the average of the answers
obtained.
Figure 5. Survey results for learning
methodology. In black and grey, the
answers from first- and second-year
students, respectively.
Figure 6. Survey results for CDF
utilization. In black and grey, the
answers from first- and second-year
students, respectively.
Figure 7. Survey results for CDF
infrastructure. In black and grey, the
answers from first- and second-year
students, respectively.
In general, the students from both years have a positive
point of view about the CD concept and they consider
that more activities would be beneficial for the learning.
Also, an improvement of the opinion about the modules
has been noticed from the second-year to first-year
students. Furthermore, students think that their skills
have been improved due to the CDF activities, being
such progress higher for the first-year students.
Nevertheless, some differences have been observed
among the two years: the perception about the CDF
activities organization has improved, the rate between
theory-based and practice-based learning is more
balanced and the opinion about the CDF functionality
got better. On the contrary, first-year students think that
they are less prepared to transmit their knowledge about
the CDF to the next generation.
5. CONCLUSIONS
Once the first academic year using the described
methodology finished, first-year students got a
satisfactory knowledge about the CDF environment and
how to face future academic work related to Concurrent
Engineering. One of the main goals achieved was the
capacity of developing new modules with the aim of
performing the preliminary design of a mission by using
the CD.
According to the survey results, the self-confidence on
transmitting the knowledge and skills related to CDF is
better in second-year than in first-year students. This
might be the consequence of a lack of experience in
CDF activities, combined with the logical lack of
training on the second-year MUSE subjects.
However, to achieve the total usefulness of the
described methodology, it is necessary to complete
several academic years, in order to generate an
appropriate dynamic.
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