This paper describes a collaborative engineering process developed by the Marshall Space Flight Center's Advanced Concepts Office for performing rapid preliminary design and mission concept definition studies for potential future NASA missions. The process has been developed and demonstrated for a broad range of mission studies including human space exploration missions, space transportation system studies and in-space science missions. The paper will describe the design team structure and specialized analytical tools that have been developed to enable a unique rapid design process. The collaborative engineering process consists of integrated analysis approach for mission definition, vehicle definition and system engineering. The relevance of the collaborative process elements to the standard NASA NPR 7120.1 system engineering process will be demonstrated. The study definition process flow for each study discipline will be will be outlined beginning with the study planning process, followed by definition of ground rules and assumptions, definition of study trades, mission analysis and subsystem analyses leading to a standardized set of mission concept study products. The flexibility of the collaborative engineering design process to accommodate a wide range of study objectives from technology definition and requirements definition to preliminary design studies will be addressed. The paper will also describe the applicability of the collaborative engineering process to include an integrated systems analysis approach for evaluating the functional requirements of evolving system technologies and capabilities needed to meet the needs of future NASA programs

Hopkins, Randy

Jones, David

Mulqueen, Jack

NASA Technical Reports Server

 American Institute of Aeronautics and Astronautics 
 
 
1 
The MSFC Collaborative Engineering Process for 
Preliminary Design and Concept Definition Studies 
 
Jack Mulqueen
1
 
Marshall Space Flight Center, MSFC, Alabama 35812 
 
David Jones
2
 
Marshall Space Flight Center, MSFC, Alabama 35812 
 
Randy Hopkins
3
 
SAIC/Marshall Space Flight Center, MSFC, Alabama 35812 
 
 
This paper describes a collaborative engineering process developed by the Marshall 
Space Flight Center’s Advanced Concepts Office for performing rapid preliminary design 
and mission concept definition studies for potential future NASA missions. The process has 
been developed and demonstrated for a broad range of mission studies including human 
space exploration missions, space transportation system studies and in-space science 
missions. The paper will describe the design team structure and specialized analytical tools 
that have been developed to enable a unique rapid design process. The collaborative 
engineering process consists of integrated analysis approach for mission definition, vehicle 
definition and system engineering. The relevance of the collaborative process elements to the 
standard NASA NPR 7120.1 system engineering process will be demonstrated. The study 
definition process flow for each study discipline will be will be outlined beginning with the 
study planning process, followed by definition of ground rules and assumptions, definition of 
study trades, mission analysis and subsystem analyses leading to a standardized set of 
mission concept study products. The flexibility of the collaborative engineering design 
process to accommodate a wide range of study objectives from technology definition and 
requirements definition to preliminary design studies will be addressed. The paper will also 
describe the applicability of the collaborative engineering process to include an integrated 
systems analysis approach for evaluating the functional requirements of evolving system 
technologies and capabilities needed to meet the needs of future NASA programs. 
 
I. MSFC Advanced Concepts Office Team Structure 
 
The Marshall Space Flight Center (MSFC) Advanced Concepts Office (ACO) utilizes a unique collaborative 
engineering approach for conducting mission architecture and concept definition studies in support of pre-phase A 
and phase A project formulation of potential future NASA missions. The Advanced Concepts office uses a 
permanently co-located team of specialized multi-discipline design engineers and a streamlined systems-based 
design process to perform a broad range of technical studies. The MSFC Advanced Concepts Office design team 
conducts Earth-to-orbit launch vehicle systems studies, robotic and science mission studies and human space 
exploration studies. The multi-discipline design team provides a unique capability to perform integrated systems 
analysis, mission analysis, system architecture assessments and subsystem design analysis for concept definition 
studies. The team structure of the MSFC Advanced Concepts Office is shown in Figure 1. Each team is composed of 
design analysts representing the design disciplines listed for each team. 
 
 
                                                          
1
 Aerospace Engineer, MSFC Advanced Concepts Office/ED04 
2
 Aerospace Engineer, MSFC Advanced Concepts Office/ED04 
3
 Aerospace Engineer, MSFC Advanced Concepts Office/ED04 
https://ntrs.nasa.gov/search.jsp?R=20120001572 2019-08-30T19:03:06+00:00Z
 American Institute of Aeronautics and Astronautics 
 
 
2 
 
 
Figure 1. Advanced Concepts Office Team Structure 
 
II. Collaborative Engineering Tools 
 
The Advanced Concepts Office uses a wide array of computer design analysis tools. The use of industry 
standard computer tools allows high fidelity engineering analysis based on widely accepted modeling techniques 
and capabilities. In many studies it is possible to incorporate higher fidelity analyses such as finite element thermal 
and structural modeling into conceptual pre-phase studies. This capability allows consideration of subsystem trades 
and design analysis that would otherwise be beyond the scope of pre-phase A conceptual studies. Due to the 
specialized nature of many Advanced Concepts studies, many additional in-house developed tools have been created 
to perform spacecraft performance analysis and subsystem design analysis. These specialized tools allow efficient 
analysis for preliminary design trades and concept definition. The Earth-to-orbit analysis tools developed by the 
Advanced Concepts Office allow extremely efficient analysis of launch vehicle design options, including multiple 
liquid and solid propulsion systems, stage configurations and payload carrying options. Also among the unique 
capabilities possessed by the Advanced Concepts office is the ability to perform broad parametric sizing and 
performance analysis of space transportation system architectures. The capability to perform integrated analysis of 
Earth-to-orbit launch vehicle and in-space transportation architectures provides a unique optimization capability. 
The mission analysis tools and capabilities to perform Earth-to-orbit and in-space trajectory analysis and orbital 
analysis provide a significant capability that is integral to the comprehensive analysis of mission architectures. The 
primary engineering analysis and design tools used by the Advanced Concepts Office are summarized in Table 1. 
 
 
 
System Analysis
Systems Engineering
Configuration, Payloads
Mission Analysis
Propulsion
Avionics & GN&C
Power
Thermal
Structures
Mass Summary
Planetary Surface Systems
Space Architecture
Human Factors
Graphics/Animation
Earth-to-Orbit Transportation Team: Space Systems Team:
Advanced Concepts Office Management
Systems Analysis
Systems Engineering
Mission & Trajectory Analysis
Configuration & Design
Structures
Propulsion
Launch Vehicle Weights & Sizing
 American Institute of Aeronautics and Astronautics 
 
 
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Table 1. Advanced Concepts Office Design Tools 
Design Tool Function 
POST – Program for Optimizing Space Trajectories Launch vehicle trajectory and performance analysis 
LVA – Launch Vehicle Analysis Launch vehicle structural analysis 
INTROS – Integrated Rocket Sizing Program Launch vehicle sizing and performance analysis 
Copernicus, MIDAS, MaNE, In-Space trajectory analysis 
Thermal Desktop and in-house thermal analysis tools Spacecraft thermal analysis 
FEMAP w/NX NASTRAN, Hypersizer Spacecraft structural analysis 
In-house power system tools Solar array sizing and spacecraft power system analysis 
In-house attitude control system tool GN&C subsystem sizing 
In-house propulsion system tool Propulsion system analysis 
COPA – Computerized Optimum Performance Analysis In-space stage sizing and performance analysis 
Transportation Architecture Analysis Parametric transportation system analysis 
ProEngineer Vehicle design and configuration 
3D Studio Animation development 
vDOT Design process and data management 
 
III. Collaborative Systems Based Design Process 
 
The collaborative design process used by the Advanced Concepts Office has evolved over many years of conducting 
a wide range of conceptual design studies in support of virtually every NASA initiative and program over the past 
several decades. The process has been modified to adapt to changes in NASA emphasis from technology 
development to science missions to major flight system programs. The collaborative design process is based on a 
comprehensive systems based approach that is valid across the broad spectrum of NASA programs and conceptual 
analysis. The foundation of the collaborative design process is sequential systems analysis process that begins with 
mission and system functional analyses to identify the top level mission objectives and requirements. The design 
process consists of three iterative processes for mission definition, vehicle definition and system engineering. The 
Advanced Concepts Office collaborative design process is illustrated in Figure 2. The mission definition process 
includes analysis tasks to define the mission profile and identify the range of mission options that comprise the 
mission trade space. Based on the mission requirements and mission trade space, initial spacecraft vehicle options 
and design ground rules and assumptions are defined. This process is often iterative in nature, as mission 
requirements are derived from analysis of the mission and vehicle trade space. The results of the mission definition 
iterations contribute to the definition of the mission concept. 
 
The vehicle definition process is closely linked to the mission definition process. The vehicle definition is based 
on requirements derived from the mission analysis which becomes the basis for vehicle performance and subsystem 
design assumptions. The initial vehicle design ground rules and assumptions not only shape the vehicle options and 
subsystem trades, but may eventually serve as the initial vehicle and subsystem requirements. The subsequent 
analysis of subsystem design trades and subsystem design analysis contribute to the definition of the vehicle 
concept. 
 
In parallel with the mission and vehicle definition processes, system engineering processes are conducted to the 
extent possible for pre-phase A and conceptual design studies. These initial system engineering activities are 
compliant with the to the established NASA project formulation guidelines as specified in NASA Procedural 
Requirements document NPR 7120.1.  The system engineering products developed at this early stage of program 
maturity often contribute to the specified system engineering products required for the Mission Concept Review 
(MCR) program key decision point (KDP) as listed in Table 2. The initial system engineering activities consist of 
initial concept of operations and requirements definition. In addition initial system risk identification is often a 
valuable component of the system analysis. The system engineering analyses, integrated with the mission and 
vehicle concepts contribute to the overall definition of the system concept. 
 American Institute of Aeronautics and Astronautics 
 
 
4 
 
Figure 2. Systems Based Collaborative Design Process 
 
 
Table 2. Systems Based Collaborative Design Process 
MCR Criteria (NPR 7123.1A)  Pre-Phase A Study Products 
Mission Goals and Objectives Mission Concept Definition  
Preliminary Requirements Mission Requirements Inputs 
Spacecraft Requirements Inputs 
Evaluation of Alternative Concepts Trade Study Results 
Alternative Configuration Evaluation 
Concept of Operations Mission Analysis Results 
Design Reference Mission Summary 
De-Scope Options De-Scope Options Summary 
Risk Assessment and Mitigation Strategies Project Risk Analysis Inputs 
Technical Plans for Next Phase Draft Phase A Technical Plan Inputs 
Measures of Effectiveness  Mission and Vehicle trade studies  
Life Cycle Support Strategies Project Cost and Schedule Inputs 
Technically Feasible Mission Concept Mission Analysis Results 
Preliminary Mission Architecture  
Credible Cost & Schedule Estimates Cost and Schedule Inputs 
Evaluation of Existing Assets Trade Study Results  
Preliminary Mission Architecture 
Vehicle
Definition
Systems 
Engineering
Preliminary 
Mission Analysis
Mission Trade 
Space Definition
Vehicle Trade 
Space Definition
Preliminary 
GR&A Definition
Architecture 
Analysis
Architecture
Definition
Mission
Analysis
Initial Con-Ops
(Mission Profiles)
GR&A
Definition
Subsystem 
Trades
Vehicle Concept 
Definition
Requirements 
Definition
Interface
Definition
Risk 
Management
System Concept 
Definition
Con-Ops 
Definition
 American Institute of Aeronautics and Astronautics 
 
 
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IV. mDot Design Process 
 
The process used by the Advanced Concepts Office is based on an iterative process which includes all mission 
and vehicle design disciplines working in a coordinated effort to converge to the desired analysis result or design 
solution. In most cases the iterations are based on reaching a converged system mass estimate. For this reason, the 
design process is called the mDot Design Process. Figure 3 shows the basic steps and information flow of the mDot 
process. The key to the efficiency of this process is the collaboration between all of the design disciplines. The 
process is based on iterative analysis and transmission of analysis results to all related design disciplines so 
dependencies and interactions between subsystems can be addressed within each design iteration. Figure 3 shows a 
simplified representation of the design process. Many of the interactions and feedback loops between design 
disciplines are not shown. Basically, the design process begins after initial study planning is completed. The study 
planning phase consists of gathering information from the study customer and defining the mission concept. The 
initial mission and vehicle trade space is also defined during the study planning process. Once the planning is 
complete, the design process is initiated with the definition of design ground rules and assumptions. Usually a joint 
design session is held in which each design discipline defines initial ground rules and assumptions. The initial 
ground rules and assumptions are documented and serve as the starting point for the design iteration. The ground 
rules and assumptions are revisited each iteration because in many cases they must be adjusted as the study 
progresses. The mission analysis tasks are closely related to the ground rules and assumptions since the mission 
profile, trajectory, orbit analysis and mission delta-velocity budget are all crucial to beginning many of the 
subsystem analyses.  In many cases, an initial vehicle configuration is defined as a starting point for the subsystem 
design trades. Once there is sufficient information available to begin the vehicle subsystem analysis, the actual 
design iterations can begin. Within each design iteration data is passed between subsystem designers in a highly 
interactive fashion. Efficient communication, data management and documentation of design results are crucial to 
maintain the efficiency of the design process. In addition, each discipline maintains a keen awareness of the 
interactions and dependencies between subsystems. This allows overall system optimization of design results. 
 
Figure 3. mDot Collaborative Design Process 
GR&A
Mission 
Analysis
Power
Avionics
Propulsion
Thermal
Structures
Factors of Safety Structure Mass
M
P
S 
Ta
n
k 
M
as
s
TCS Power
Avionics Power
Tank Insulation Mass
TCS Mass
Power Sys Mass
Avionics Mass
MPS & RCS Mass
M
a
ss
 P
ro
p
e
rt
ie
s
Maneuver
Prop
Eclip
se P
erio
d
s
C
o
m
m
C
o
verage
Science
Requirements                 
Instrument Power
Slew Rates
Instrument Heat Rejection
M
ar
gi
n
 S
tr
at
eg
y
Configuration
B
eta A
n
gle
Lau
n
ch
 Lo
ad
s
Instrument Field of Regard
Animation
 American Institute of Aeronautics and Astronautics 
 
 
6 
The objective of the design iteration process is to converge on the design concept for each subsystem. Mission 
analysis is performed each iteration to evaluate the vehicle performance, including propulsion system propellant 
requirements. As the design iterations progress, the convergence of the design solution is usually measured by the 
change in vehicle dry mass and propellant mass. When the iterations are complete the study results are documented. 
In many studies additional system engineering activities augment the vehicle concept definition. As stated earlier, 
the system engineering tasks may include requirements analysis, risk identification or development of other system 
engineering products. The Advanced Concepts has developed a standard study documentation process to compile 
the study results and present them to customers and stakeholders.  
V. Integrated Systems Analysis 
 
The collaborative design process can be applied to a wide range of study types and different levels of systems 
analysis. While the collaborative design processes are well suited for vehicle concept definition studies, the same 
process provides a framework for evaluating system interactions and dependencies at a much higher level as well. 
The systems based approach has been used to define and evaluate space transportation architectures, evaluate 
mission infrastructure options and assess technology needs. The systems analysis approach is illustrated in Figure 4. 
The approach represents a sequential process for defining and evaluating future NASA programs and mission 
options. The process begins with broad mission and system functional assessments. Based on the mission 
requirements, the mission architecture options and elements can be defined. The architecture assessment usually 
consists of trade studies and evaluation of mission options, spacecraft transportation options and definition of 
mission payloads. Assessment of future NASA programs often also includes evaluation of emerging technology 
capabilities and development needs. The integrated system based approach and collaborative engineering process 
developed by the MSFC Advanced Concepts Office provides a unique capability for evaluating evolving NASA 
program and missions in a highly effective and efficient manner. 
 
Figure 4. Systems Based Analysis Process 
Systems Analysis
Trajectory/Performance
Subsystem Weights and Sizing
Vehicle/Stage Weights and Sizing
Structural/thermal loads/analysis
Cost assessment
Risk assessment
Reliability assessment
Ground/space operations
Induced environments
Natural environments
Mission 
Requirements
Functional 
Assessment
Architecture 
Trades/Assessments
Initial 
Architecture/Element 
Definition
Technology 
Assessment
Technology 
Goals/Objectives


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