1. Low-Fidelity Space Mission Architecture Design
Tools for Agile Design
Anthony Hennig, Rochester Inst. of Technology, Rochester,
New York
Dr. Dale Arney, NASA Langley Research Center, Hampton,
Virginia
Overview
Within the SpaceMission AnalysisBranch of the Systems
Analysis and Concepts Directorateof NASA Langley, there is a
growing need for an adaptiveand responsivemission
architecturedesign process.In order to facilitatethis,the
Agile Design Philosophy,which focuses on creatingproducts
quickly atlowfidelity to receive feedback, would be
preferable to implement rather than a process driven design
philosophy for mission architectures.
This tool set was originally designed to help move ideas from
an initial conceptstageto a presentable product atthe Pre-
PhaseA completion status within a few hours.
Tool Suite Development
The listof items within the tool suitewas initially developed
by analyzingPhaseAconcept of operations and identifying
Figures of Merit as well as pieces of data commonly relayed
to specialists and analysts.Furthermore, stakeholders were
interviewed to identify major assets and evaluationsto have
a concept ready for further analysis.
Tools were developed by either re-adaptingtools designed
for specific concepts previously,by designingan interfaceto a
pre-existingdatabase,developing a databaseor developing
the tool from firstprinciples.Seen below, bolded tools were
developed from external sources or from tool development
previously within the branch for other specific projects.
The tool suitefocuses on five major categories of mission
architecturedesign, each with element sub-tools:
Human Operations
Short Term Habitat(1-20 Days), Long Term Habitat (50-1000
Days), Destination Campaign
Power System Sizing
Fission Power Sizing, Solar Cell/Fuel Cell Sizing
Science System Sizing
Rover Sizing, Orbiter Sizing, In Situ Resource Utilization
(ISRU) Plant Sizing
Vehicle Trajectory and Ephemeris
Helio-centric Trajectory, Body-Centric Intercept, Body-Centric
Orbit Change, Body-Centric Ascent/Descent, Thermal
Protection System(TPS) Sizing
Propulsion Sizing
Small Vehicle/One-Way Sizing, Large Vehicle/Multiburn
Sizing
Tools are combined as necessary to create a network of
elements, communicatingmajor utilities of mass,power,
volume, and vehicletrajectory/ephemeris either in
automatically generated reports or “Baseball Cards.”
Developed in MicrosoftExcel, the system elements can be
put together to form an automatically generating
architectureor fill in a specific knowledgegap for a specialist.
Test Cases
To demonstrate the tool suite, architectures were made to
demonstrate the system and ease of the mission architecture
development process.Master Equipment Lists were
generated for every mission architectureand mass estimates
were made.
Two test cases were specifically developed to demonstrate
the validity of the tools for the Mars Science Lab in Table1
and VikingOrbiter and Lander pair in Table2 and masses
were compared. TPS and Rover sizingestimates did use test
caseelement knowledge in the development of the toolset.
Element % Error
Mass at Mars Intercept (ThermalProtection,
Skycrane, Rover)
2%
BackshellSep.(Skycrane,Rover) 2%
Rover 5%
Table 1:Mars Science LaboratoryComparison
Element % Error
Mass at Mars Insertion(PropulsionUnit, Power,
Orbiter, EDL Package)
3%
EDL Package(TPS, Lander) 6%
TPS 16%
Lander 8%
Table 2: Viking Orbiter and Lander Comparison
Within two days,seven notional mission architectures were
developed for Mercury Rovers, Lunar PropellantISRU, Mars
Sample Return, Venus Teleoperations Station, Lunar Outpost,
Phobos Short Term Habitatand Mars SpaceStation.
Conclusions
In lightof these outcomes, this system is ableto provide a
rough assessmentof major utilities in mission architecture
design (Mass,Power, Volume, Ephemeris/Trajectory) in a
shortperiod of time (two hours/architecture).
Further work will focus on developingautomated data
aggregation and presentation processes and implementing
optimization techniques within the framework.