1. Iterative, Concurrent Design of Advanced Space Transportation Systems
EUCASS 2015
Vanessa Clark

2. Contents Introduction Collaborative and Concurrent Design
> CLaVA > Vanessa Clark • EUCASS >
Contents
Introduction
Collaborative and Concurrent Design
Space Transportation System Process Chain
Enabling Infrastructure and Methods for CLaVA
Distributive Design
Model-Based Systems Engineering
Object Oriented Methods
Conclusion
Source: NASA

3. Introduction Scope of this presentation:
> CLaVA > Vanessa Clark • EUCASS >
Introduction
Scope of this presentation:
New initiative from DLR: Collaborative Launch vehicle Analysis (CLaVA)
The development of a design process for STS (space transportation systems)
Early-phase design
Goal: enhance the interconnectivity and build competences between various DLR institutes in the area of space transportation. The aim is to make cooperation faster, more efficient and error-free.
(investigation necessitated during requirements definition)

4. Versatility, flexibility, robustness Introduction
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Budget, time constraints
Market and commercial aspects
Versatility, flexibility, robustness
Performance
Political boundary conditions
Introduction
Motivation for this work:
Rockets are hard (more on that later).
External constraints are more predominant than technical complexities in STS design!

5. Collaboration is key! Introduction
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Introduction
Collaboration is key!
Map of Collaboration between Researchers
Source: science-metrix.com

6. Introduction Materials (WF) System, configuration, trajectory (RY)
> CLaVA > Vanessa Clark • EUCASS >
Introduction
Map of Collaboration between Researchers
Source: science-metrix.com
Source: LEGO
System, configuration, trajectory (RY)
Flight dynamics and control (SR)
Solid rocket motors (AS)
Materials (WF)
Structure(FA) (BT)
Liquid engines (RA)
Aerodynamics, aerothermodynamics, flight dynamics and control (AS)
Ground stations (RA)
Combustion (VT)

7. Collaborative and Concurrent Design
> CLaVA > Vanessa Clark • EUCASS >
Collaborative and Concurrent Design
Let’s have this…..
….. and avoid this!

8. Collaborative and Concurrent Design
> CLaVA > Vanessa Clark • EUCASS >
Collaborative and Concurrent Design
DLR has a strong heritage in collaborative design… ?
Aircraft
Satellites
Space Transportation

9. Collaborative and Concurrent Design
> CLaVA > Vanessa Clark • EUCASS >
Collaborative and Concurrent Design
Objective: provide a new, flexible design environment to foster collaboration between experts in STS design

10. Collaborative and Concurrent Design
> CLaVA > Vanessa Clark • EUCASS >
Collaborative and Concurrent Design
CEF
Preliminary design
X-TRAS
Testing ?
Development
CLaVA
MDO
Distributive Design Environment
Model-Based Systems Engineering

11. STS Design Process What is a Space Transportation System (STS)?
> CLaVA > Vanessa Clark • EUCASS >
STS Design Process
What is a Space Transportation System (STS)?
It Shall be of Civilian Application
It Shall Concern The Vehicle
No megascale engineering projects that require large supporting infrastructures such as Space Elevators, Launch Loops, Space Cannons
It shall fly and fly fast!
Minimum velocity of the vehicle shall exceed Mach 5 at sea-level.
It shall transport some payload or a crew.
Source: ESA
Source: Virgin Galactic

12. STS Design Process Energy Level 5 6 7 8 9 10
> CLaVA > Vanessa Clark • EUCASS >
STS Design Process
Energy Level
Heavier than Air With Wing Bodies
Multi-Stage | Single Stage
Heavier than Air
With Lifting Bodies Reusable | Non-Reusable
Heavier than Air Without Lifting Bodies Reusable | Non-Reusable
Lighter than Air Reusable | Non-Reusable 5 6 7 8 9 10
 Energy level
Mach 5 6 7 8 9
25 -

13. STS Design Process Sequential Multidisciplinary Iterative
> CLaVA > Vanessa Clark • EUCASS >
STS Design Process
Sequential
Inherent sensitivities between the design domains
Parellelisation of tasks performed where possible to optimise time
Multidisciplinary
Preliminary models / analysis techniques generally much higher fidelity than for satellite design. E.g. structural analysis (beam method, FEM)
Iterative
Design must be iterated until convergence
Domains: not subsystem!

14. STS Design Process Loop 3: Subsystems Loop 2: Higher fidelity analyses
> CLaVA > Vanessa Clark • EUCASS >
Loop 3:
Subsystems
Loop 2:
Higher fidelity analyses
Loop 1: Preliminary Sizing and Layout
Loop 0:
Requirements, design space definition
STS Design Process
Domain 1
Domain 2
Domain 3
Domain 4
Domain 5
Systems engineer
MDO
Domains: not subsystem!

15. STS Design Process Domains Systems: staging, configuration, mass
> CLaVA > Vanessa Clark • EUCASS >
Map of Collaboration between Researchers
Source: science-metrix.com
Source: LEGO
System, configuration, trajectory (RY)
Flight dynamics and control (SR)
Solid rocket motors (AS)
Materials (WF)
Structure(FA) (BT)
Liquid engines (RA)
Aerodynamics, aerothermodynamics, flight dynamics and control (AS)
STS Design Process
Domains
Systems: staging,
configuration, mass
Aerodynamics
Propulsion (solid)
Propulsion (liquid)
Control (descent)
Structure
Thermal
Trajectory
Subsystems
Control (ascent)
Ground
Domains: not subsystem!

16. SED: Systems engineer decision
> CLaVA > Vanessa Clark • EUCASS >
STS Design Process
SED: Systems engineer decision

17. > CLaVA > Vanessa Clark • EUCASS > 01.07.2015
STS Design Process

18. STS Design Process Loop 0
> CLaVA > Vanessa Clark • EUCASS >
STS Design Process
Loop 0
Defines the mission statement and the project definition.
Market analyses and customer validation are performed.
The project definition, mission statement and high-level requirements are then translated into an implementation strategy.
Initial concepts and technology choices are identified through consultation with the customer.

19. > CLaVA > Vanessa Clark • EUCASS > 01.07.2015
STS Design Process

20. > CLaVA > Vanessa Clark • EUCASS > 01.07.2015
Loop 1
Propulsion:
Preliminary propulsion systems are calculated using fast engineering methods with an emphasis on system level performance and mass estimation.

21. Propulsion Block Description:
> CLaVA > Vanessa Clark • EUCASS >
Propulsion Block
Description:
The ascent and payload performance are calculated by combining more accurate results for system mass, aerodynamics and engine performance compared to loop 1.
Input:
System mass, aerodynamic database, engine performance and mission requiremenets.
Process:
Fast analytical ascent trajectory calculation and optimization resulting in vehicle payload performance.
Output:
Optimized trajectory evolution and payload mass.

22. > CLaVA > Vanessa Clark • EUCASS > 01.07.2015
Loop 1
Mass:
A preliminary mass model is constructed on system level using handbook-methods.
Tool: STSM

23. > CLaVA > Vanessa Clark • EUCASS > 01.07.2015
Loop 1
Aerodynamics:
Stability analysis related specifically to longitudinal pitch is analysed.
Trimmed aerodynamic database is composed.
Trimmability during hypersonic flight is analysed.
Trimmed aerodynamic database produced.

24. Blue, dashed vectors: Resuable launch vehicles only
> CLaVA > Vanessa Clark • EUCASS >
Blue, dashed vectors: Resuable launch vehicles only
Loop 1
Trajectory:
The ascent and payload performance are calculated by combining more system mass, aerodynamic database, engine performance and mission requirements.
Fast analytical ascent trajectory calculation and optimization resulting in vehicle performance and payload mass.

25. Trajectory Block Description:
> CLaVA > Vanessa Clark • EUCASS >
Trajectory Block
Description:
The ascent and payload performance are calculated by combining more accurate results for system mass, aerodynamics and engine performance compared to loop 1.
Input:
System mass, aerodynamic database, engine performance and mission requiremenets.
Process:
Fast analytical ascent trajectory calculation and optimization resulting in vehicle payload performance.
Output:
Optimized trajectory evolution and payload mass.

26. > CLaVA > Vanessa Clark • EUCASS > 01.07.2015
STS Design Process

27. > CLaVA > Vanessa Clark • EUCASS > 01.07.2015
Loop 1

28. > CLaVA > Vanessa Clark • EUCASS > 01.07.2015
STS Design Process

29. Loop 2 Blue, dashed vectors: Resuable launch vehicles only Green:
> CLaVA > Vanessa Clark • EUCASS >
Blue, dashed vectors: Resuable launch vehicles only
Green:
Sleder-bodied expendable rockets only
Loop 2

30. Loop 2 Loads and Structures:
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Loads and Structures:
Analysis of tanks and structural shell elements considering specific load cases and internal pressurisation facilitates the sizing and mass estimation of these components.
Stiffness and eigenfrequencies determined.
Loop 2

31. > CLaVA > Vanessa Clark • EUCASS > 01.07.2015
Ascent Control:
Controllability of the launch vehicle is analysed during the ascent with influence from external forces, internal Center of Gravity movement and nozzle vector control.
Loop 2

32. Infrastructure and Methods for STS Design
> CLaVA > Vanessa Clark • EUCASS >
Infrastructure and Methods for STS Design
Distributive design environment
Distribution
Data Management
Privilege Management
Workflow Engine
provide environment for coupling of tools to automated compute workflows.
MDO, parameter studies.
Platform Independence:
executable on different operating systems.

33. Infrastructure and Methods for STS Design
> CLaVA > Vanessa Clark • EUCASS >
Infrastructure and Methods for STS Design
Model-Based Systems Engineering
The Common Parametric Aircraft Configuration Schema (CPACS)
Describes the characteristics of aircraft and mission in a structured, hierarchical manner.
Not only product but also process information.

34. Infrastructure and Methods for STS Design
> CLaVA > Vanessa Clark • EUCASS >
Infrastructure and Methods for STS Design
Object-Oriented Methods
Time-dependancy
Association
Data base
Programming practices applied to STS design

35. > CLaVA > Vanessa Clark • EUCASS > 01.07.2015
Conclusion
The design of optimal, innovative and robust STSs poses a challenge for engineers and managers due to the complexity and sensitivity of the design parameters and disciplines!
Design process gaps have been identified. Strengthening and guidance of the cooperation between discipline experts is required.
The integration of the design process in a distributive environment and realisation of a central data model based on MBSE philosophies will be performed in subsequent activities.

36. questions? vanessa.clark@dlr.de
> CLaVA > Vanessa Clark • Kick Off>
questions?