Discover why Capella has been chosen by CT Ingenierie and its partners, and how it has been deployed for guaranteeing the correct coordination between teams, requirement following, and for a rigorous description of the sub-systems developed by their partners. CT Ingenierie is involved in the ENVOL project (European Newspace Vertical Orbital Launcher). Developing a small launch vehicle enabling cheap, frequent, and flexible access to the Low Earth Orbit. What is project ENVOL? The EU-funded ENVOL project intends to establish the first European commercial, competitive and green launch service. The project will designate an innovative and industrial low-cost launch system, then demonstrate and advance crucial launcher technologies to guarantee market preparedness and competitiveness, then prepare a business plan and identify the institutions able to attract investments.

1. Paris, 25 March 2021
Capella in the preliminary design of the
microlauncher ENVOL
Julien Morane, System Engineer at CT PARIS
Public (PU) – approved for public release
This project has received funding
from the European Union’s H2020
research and innovation programme
under grant agreement No 870385

2. 00
Agenda
Public (PU) – approved for public release

3. Agenda & objectives
CT PARIS & ENVOL project presentation.
Use of Capella in ENVOL.
 For global architecture.
 For subsystems definition.
Feedbacks and next steps in the use of Capella in ENVOL.
Public (PU) – approved for public release
01
02
03
Not a presentation of the tool itself !

4. 1.1
Agenda
CT Paris presentation
CT Paris: MBSE (Capella) history
The CT Engineering Group
CT Paris key activities
Public (PU) – approved for public release

5. The CT Engineering group: Global Engineering
Aerospace
Naval
Auto
Industrial plants
Energy
Train
Architecture
• CT Engineering is an group with more than
1500 employees spread into 5 European
countries
• We are a company eager to help its clients
succeed in their technological projects. Every
day, our engineers work side by side with
customers in various sectors in all
engineering activities across the product
lifecycle. Each one of them thrives to
understand client needs, and provide
solutions while maintaining an easy and
enjoyable customer experience.
Public (PU) – approved for public release

6. CT Paris : Bringing innovation over the whole space system life cycle
Needs
identification
Feasibility
studies
Preliminary
Design
Detailed
Design
Manufacturing, Assembly,
Integration, Test & Verification
Exploitation,
Operations
 Numerical & physical rocket
engine test bench
 Support to operational
decision making process
 Risk assessment
 System, sub-system
and components
design
 External
Aerothermodynamics
 System performances &
detailed component analysis
o Rocket engines
o Tanks
o Launcher stages
 Innovative
solutions
Phase 0 Phase A Phase B Phase E
Phase C
 Microlauncher
design
Public (PU) – approved for public release

7. 1.2
CT Paris presentation
The ENVOL project
Motivation
Implementation
CT Paris: MBSE
(Capella) history
Public (PU) – approved for public release

8. CT Paris motivations to transition to MBSE approach
 CT Paris team has been working on the design of innovative systems for over 30 years. The team is in constant
research for tools and methods to improve our efficiency to manage the increasing complexity of projects.
 By adopting a MBSE approach (at first on Phase A= feasibility studies), the team expected several benefits:
 To have a formal way to communicate on the system concept and architecture.
o Granularity and multi-level vision.
o Exploration of design hypothesis.
 To ease impact analysis and traceability between engineering levels 
 To capitalize from one study to another.
o Projects sometimes stopped and restarted.
o Time consuming to integrate new engineers on the project.
 To enable a better data & documentation management.
o Management of complexity with automation of simple tasks (documentation update).
o Prevent the silo effect.
 The fact that Capella was an open-source solution was also a driver (possibility to customize).
Public (PU) – approved for public release

9. CT Paris started to experiment successfully Capella on R&D projets
Insider: Patented net
deployed with inflatable
structure for space debris
deorbitation.
•
‘
Lessons learned made on ESA MBSE2020 workshop. Available on demand
Work done on these projects has enabled us to match our
previous creativity methods with the Arcadia concepts.
‘
Public (PU) – approved for public release

10. CT Paris started to experiment successfully Capella on R&D projets
Space Blower: Particles
ejector that can brake a
space debris for Just-in-
time collision avoidance,
and its reactive deployment
system.
See Youtube Video: ‘Space Blower™, a Just-in-time Collision Avoidance concept. A CT & CNES Patent.
Working on those projects made us understand more accurately the benefits
and limits of the MBSE approach
Public (PU) – approved for public release

11. 1.3
CT Paris : MBSE (Capella) adoption
The ENVOL project The New Space
The European ENVOL
consortium
Engineering challenges
Public (PU) – approved for public release

12. CT Paris: a recognized actor of the New Space
Satellite constellation
(credit: ESA)
This project has received funding from the European Union’s H2020 research and innovation programme under grant agreement No 870385
 Satellites are becoming more and more standardized and
miniaturized.
 Satellites operators are demanding higher launching rates for
their satellites with more flexibility regarding the launch.
 ‘Big’ rockets generate constraints for small payloads
operators
 Hence the development of numerous launch compagnies that are
searching to develop cheaper, frequent and more flexible ways
to reach the space for small satellites.
Roxane
launch vehicle
The H2020
ALTAIR project
Public (PU) – approved for public release

13.  ENVOL  European NewSpace Vertical Orbital Launcher.
 In its H2020 research program, several projects have been funded to ensure
European independant access to space (SMILE and ALTAIR finished in 2019).
 The hybrid technology* (mix of solid and liquid chemicals to propel the rocket) offers several
advantages: it is easy to operate, is reliable, controlable and green.
 A consortium of nine compagnies with the expertise to turn a hybrid motor component into a full system
has been set up.
 Technological demonstrators will be outputs of this project: ENVOL aims to rocket from R&D to
industrial phase.
* if interested, see https://www.nammo.com/story/a-very-different-way-to-launch-into-space
This project has received funding from the European Union’s H2020 research and innovation programme under grant agreement No 870385
The ENVOL project
Two views on ENVOL concept
Public (PU) – approved for public release

14. Propulsion
Payload
Composites
structures
Avionics
& Ground
segment
Turbopump
Launch base
Propellant
supply
Market &
Customer
needs
LV design
System
Engineering
ENVOL consortium: business trades to develop an operational microlauncher
This project has received funding from the European Union’s H2020 research and innovation programme under grant agreement No 870385
Public (PU) – approved for public release

15. 2.1
Capella in ENVOL
Global design phase
Creativity Support
System Engineering Support
Project main phases
and their associated needs
Public (PU) – approved for public release

16. Arcadia & Capella as a support to create a new system
 Most of the ENVOL components have not yet been
designed and the use of Shelf Component is limited.
 Thus, the structuration and formalization of design
hypothesis & reference architectural choices is key.
 The need to give every stakeholder a global vision
of the launch vehicle is also an important matter to
take into account.
Public (PU) – approved for public release
impact

17. Setting the scope of Capella in the System Engineering activities
• The ENVOL projects targets to develop a Preliminary Design
(Phase B) of the launcher development
• The ECSS (European Cooperation for Space Standardization)
have set up a list of deliverable documents to be produced for
every milestones of the space projects.
• The system Engineering team of the ENVOL project has then
write a System Engineering Plan defining the scope of its
activities and the expected outputs it will provide.
• The product life cycle phases considered will mostly be the
operational phases, as manufacturing and AIT are topics
considered in next phases of the system definition.
• The question has then be asked : How far can we use Capella
to fulfill those expectations ?
Typical project life cycle
from ECSS-M-ST-10C
System enginneirng
deliverable per phases
from ECSS-E-ST-10C
Public (PU) – approved for public release

18. Three specific use of Capella for three ENVOL phases
• The planning of the ENVOL project consists in 3 main phases:
• Those phases are not strictly linear:
• Overlapping between those phases
• Heterogeneity with regard to component considered.
1: Global design
• Based on the input of the
previous projects,
definition of High Level
Requirements and a
global architecture of
the Launch Vehicle (High
level design choices) are
made during this phase.
2: Subsystems
detailed conception
• Translation of High
Level Requirements
into technical
requirements that
will lead the main
components design.
3: Demonstrators
conception, manufacturing
and tests.
• Building of
demonstrators to rise
the TRL of critical
technologies.
Public (PU) – approved for public release
35
subsystems
identified
4
demonstrators

19. 2.2
Capella in ENVOL
Global design phase
Subsystems details conception phase
Challenges
Allocated means
Results
Public (PU) – approved for public release

20. Challenges of the ENVOL global design phase
 The main outputs of this phase are:
• Market assessment
• High Level Requirements
• Concept of operations
• Preliminary Launch Vehicle design loop (configuration, arrangement of propulsion modules, …)
 Three main key points have been spotted:
• Heritage from past H2020 projects (2 previous system conceptions) This asset for the
project had to be well managed to be the most usefull possible
• Different partners will provide different level of analysis in parallel. Links between those
analysis have to be created a posteriori
• Timing constraint: Engineers can not wait the detailed definition of the system to start their
analysis.
 Market assessment
 High Level Requirements
 Concept of operations
 Preliminary Launch Vehicle design loop (configuration (number of stages, arrangement of
equipments & propulsion modules, …) and first optimization loop)
 Different partners will provide different levels of analysis in parallel. Links between
those analysis have to be created a posteriori.
 Timing constraint: Engineers can not wait the detailed definition of the system to start
their analysis.
 Heritage from past H2020 projects (2 previous system conceptions). This asset for
the project has to be well managed to be as useful as possible.
Public (PU) – approved for public release

21. Arcadia customization for the System design conception phase
• Arcadia provides a framework to define a system architecture. However, the architecture definition was not the
first objective of the use of Capella in the project. The project schedule has prevented to use Arcadia « strictly »
• The main role of the system engineer in this phase was then to map the inputs he received from the partners with
the Arcadia concepts
• Then the engineer was in charge to ‘recreate coherency’, using Arcadia to ‘fill the holes’
and offer a critical view to the inputs provided by its partners.
++
+
+
-
System
functions
components
Requirements
Physical
Links
Physical
functions
Public (PU) – approved for public release
Scenario

22. Capella can help to solve the « TBD issue »
In this phase, Capella main purpose was descriptive.
The model was build as a reference global architecture, use as support
for co-engineering sessions
We used extensively diagrams that can provide an overview of general elements
(assemblies, ground systems, IF…)
Those global view helped to define how designs changes in one
components impact other components, especially with the interface
définition (concurrent engineering). This analysis was made after the co-
engineering sessions.
Those diagrams were work documents, that also helped to manage the
traceability of hypothesis and TBD/TBC points raised during design
sessions.
• Extended usage of notes in diagrams
• Identification of design hypothèses though Management tab
Public (PU) – approved for public release

23. Several profiles needed to deploy Capella on ENVOL
One Capella leader (CT PARIS): Responsible of the modelisation
• Profile: Space Engineer that can handle information coming from various domain, with high other
technical responsibilities on the project. Has already experience with Arcadia/Capella.
• Choice have been made to use one engineer with two competencies that will both keep
coherencies regarding the Capella model and the technical data it will handle
A Capella team (CT PARIS)
• Capella is deployed within CT Paris through the embedded git tool. CT Engineers knows how to
use the software, and are able to edit the ENVOL model (with MBSE responsible in the loop)
External partners are not able to edit the model.
• All the information they provide passes through the MBSE responsible.
• The modelling is done in parallel with the development on key components during co-engineering
sessions. At each loop of the design of a component, the modeling of this component is updated
with the new inputs / modifications that arise.
• CT informs any partners when elements / data impacting its works are modified.
Public (PU) – approved for public release

24. 2.3
Global design phase
Subsystems
conception phase
Requirement Engineering
Interface Management
Use of PBS for budget
Public (PU) – approved for public release

25. Three main activities for the conception of the subsystems
• At the end of the first phase, System Requirement Review and first loop of preliminary design has been conducte
• A strong (around 380 Physical Components) Capella model has been developed to support those activities. 35 s
systems were identified.
Second phase goes into subsystems design. It uses this model for three main activities:
• At the end of first phase, System Requirement Review and first loop of preliminary design has been
conducted.
• A strong (around 380 Physical Components) Capella model has been developed to support those
activities. 35 sub-systems were identified.
Requirement
Engineering
• All high level requirements
have to be correctly
translated in Technical
Requirements, allocated
to components.
• Cross-dependencies have
to be identified.
Interface Engineering
• Some of them are defined
and designed by CT, most
of them are designed by
external parters.
Budget allocation
& repartition
• Mass, power, costs…
Public (PU) – approved for public release

26. Capella for the identification and management of requirements
• The Main outputs are generated with M2Doc (automation + readable by all partners). Iterations loops are then initiatied:
• Technical requirement specification documents, generated for each sub-system with M2Doc
• High Level Requirements Traceability Matrix
• Empty verification matrix for each sub-system.
• The Technical requirements specification templates have the following structure:
• Feedback: possible ameliorations 
• Reverse M2Doc’ (import from structured documents)
• Requirement management support: Automation of requirement identification, possibility
to structure the elements place in M2Doc lists (ex: ID sorting)
Life cycle of the components (RPLs)
Functional analysis made in LA (functional chain) Sub-system architecture
Public (PU) – approved for public release

27. Capella for interface identification and definition
• Internal (between stages, structural elements,…) and external (with
Spaceport and Payload) interfaces are crucial in the project.
• For interfaces designed by our partners, Capella role is restricted to
interface identification and specification.
• Physical Link / Functional exchanges description will then link the
model elements to the documents on which their design is
detailed.
• For interfaces defined by CT, we are also trying to include the interface
design in the Capella model .
• Extensive use of PVMT (Property Value Management Tool), with
standard values used to defined interfaces defined in associated
ECSS
• Still experimenting
Public (PU) – approved for public release

28. 3.1
Use of Capella:
General Feedbacks
Next steps for Capella and ENVOL
Public (PU) – approved for public release

29. General Synthesis on the use of Capella
Comparison with our first objectives => Globally positive, not
possible to explore alternatives as much as we expected.
• For the construction of reference architecture (Creativity).
• For subsystems specification, interfaces identification & traceability building between
several analysis levels (routine system engineering operations).
Capella is a global tool. It has proven to be an important tool to
accompany CT Paris during several phases of the ENVOL project.
The team was able to match Arcadia concepts with our previous
analysis methods.
Automation on several tasks (document generation, management
of model,…) has increased our team’s productivity.
Public (PU) – approved for public release

30. Training a Capella team rather than a Capella champion.
 Although it is important to have a modelisation leader, its efficiency increases together with the
number of workers that are able to edit the model the right way.
o The tool must be mastered: How to navigate into the model and change it.
o The method and concepts must be known: not only being able to change the model, but
doing it in a relevant manner.
o Time is an important factor in this process
 Thus, the Capella leader must also be:
o A proselyte.
o a teacher.
o An after-sales advisor.
Public (PU) – approved for public release

31. 3.1
-Use of Capella: General Feedbacks
Next steps for Capella and ENVOL
Public (PU) – approved for public release

32. Next steps for Capella and ENVOL
 Next phase: DEMONSTRATORS
 Study extension to following life cycle phases.
 Next problematic: NEW VERSION
 Preparing the v2 of the launcher.
 Next ambition: ANALYSIS
 Integrating CT tools with Capella.
o Modelisation / Simulation / Optimization.
Public (PU) – approved for public release

33. Contacts CT Paris
Stanislas Choppin, Site Manager, +33 6 40 86 88 14, stanislas.choppin@ctingenierie.com,
Julien Morane, MBSE responsible, +33 7 84 17 68 19, julien.morane@ctingenierie.com
Special thanks to Simon Rommelaere