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Assessing the Impacts of Fractionation on Pointing-Intensive Spacecraft
American Institute of Aeronautics and Astronautics Space 2009 Conference and Exposition
September 14-17, 2009
M. Gregory O’NeillGraduate Research Assistant
mgoneill@mit.edu
Annalisa Weigel, PhDAssistant Professoralweigel@mit.edu
Department of Aeronautics and AstronauticsMassachusetts Institute of Technology
Cambridge, Massachusetts
• Problem Formulation
• Methodology & Analysis
• Synthesis
• Conclusion
Agenda
• Conclusion
© 2009 Massachusetts Institute of Technology Slide 2
Enablers
S3
Enablers
Module 1 Module 2
Concepts & Terminology
Fractionated Spacecraft(O’Neill, 2009)
Problem Formulation
S2
S3
S4
S4
S5
Shared Resource Enablers
Subsystem Payload
S1
S1 S2
Representative
EnablerComm_CS_C&DH ADS_G�S Power
Application antenna IMU (receiving) solar array
Developmenttasking, schedule, &
control
(autonomous) relative
navigationlaser diode array
Domain
Enablers
Module 3Shared Subsystem Resources(O’Neill 2009)
PL PL
S4S5
© 2009 Massachusetts Institute of Technology Slide 3
Concepts & Terminology
Fractionated Spacecraft(O’Neill, 2009)
Problem Formulation
S2
S3
S4
S2
S3
S4
S/C-to-Ground
Directional AntennaSubsystem Payload
S1S1
Source Recipient
S3S4
S5
S1 S2
Representative
EnablerComm_CS_C&DH ADS_G�S Power
Application antenna IMU (receiving) solar array
Developmenttasking, schedule, &
control
(autonomous) relative
navigationlaser diode array
DomainShared Subsystem Resources(O’Neill 2009)
PLPL
S4S5
S4
S5
Omni-antenna
or
Directional Antenna
© 2009 Massachusetts Institute of Technology Slide 4
Recipient
PL
Monolithic Spacecraft
Fractionated Spacecraft
Mission Type Spacecraft Type
Context
Motivation: Critical QuestionProblem Formulation
Remote Sensing Mission
Launch, Technical, Environmental, Operational
Pointing-Intensive~36 mas pointing tolerance
Lifecycle Uncertainties(O’Neill, 2009)
GEOEye-1Source: GEOEye
A Fractionated SpacecraftSource: DARPA
Value Proposition
Value Proposition
- Performance - Lifecycle Cost- Mission Lifetime - Mass- Propellant Usage
Given the context, how do monolithic and fractionated spacecraft value propositions compare?
© 2009 Massachusetts Institute of Technology Slide 5
• Problem Formulation
• Methodology & Analysis
• Synthesis
• Conclusion
Agenda
• Conclusion
© 2009 Massachusetts Institute of Technology Slide 6
� Market Supply & Demand
� National Security
� Technical
� Environmental
� Funding
� Operational
� Launch
� Programmatic
Methodology: Spacecraft Evaluation ToolMethodology &
Analysis
Lifecycle Uncertainties
Physics-based Model Cost ModelSpacecraft Architecture
Models and Model Processes
Operationalize
via a
Monte Carlo Analysis
Lifecycle & Design Input Group
Component-Level Outputs
Physics-based Model Cost ModelArchitecture Input Group Payload
Size/Volume
Power
Launch Vehicle
COCOMO II
Parametric CERs
Mass
Subsystems
Launch Vehicle Input Group
Dynamic Model
Subsystem-Level Outputs
Module-Level Outputs
System-Level Outputs
© 2009 Massachusetts Institute of Technology Slide 7
Case Study InputsMethodology &
Analysis
No Shared Resources
Shared Resources1. Comm_CS_C&DH 2. ADS_GNS
Shared Resources1. Comm_CS_C&DH 2. ADS_GNS
Lifecycle & Design
Spacecraft Architecture
Category Input Value Units
Altitude 700 km
Inclination 98 °
Mission Lifetime 7 years
MCA no. of Trials 2,500 -
PoIM 1.5 %
Payload Resolution 0.5 m
Variable CONOPS Separation Distance 20, 1000, 5000 m
Orbit
Dynamic
Constant
Nu
mb
er
of
Mo
du
les
2. ADS_GNS 2. ADS_GNS 3. Power
1 Module
2 Modules
Arch 1
Arch 4Arch 7
Arch 2Arch 27
3 Modules Arch 10Arch 13
Arch 8Arch 26
4 Modules Arch 22Arch 25
Arch 20Arch 29
Monolithic S/C
Use of Shared Subsystem Resources
© 2009 Massachusetts Institute of Technology Slide 8
900
1,000
1,100
1,200
1,300
1,400
1,500
1,600
1,700
1,800M
ed
ian
Sy
ste
m D
yn
am
ic L
ife
cycl
e C
ost
(FY
20
08
$M
)
Results: Inter-module Separation DistanceMethodology &
Analysis
300
400
500
600
700
800
900
1,600 2,000 2,400 2,800 3,200 3,600 4,000 4,400 4,800
Me
dia
n S
yst
em
Dy
na
mic
Lif
ecy
cle
Co
st (F
Y2
00
8$
M)
System Mass (kg)
Arch 1 Arch 2 Arch 4
Arch 27 Arch 7 Arch 8
Arch 10 Arch 26 Arch 13
Arch 20 Arch 22 Arch 29
Arch 25
© 2009 Massachusetts Institute of Technology Slide 9
900
1,000
1,100
1,200
1,300
1,400
1,500
1,600
1,700
1,800M
ed
ian
Sy
ste
m D
yn
am
ic L
ife
cycl
e C
ost
(FY
20
08
$M
)
Results: Inter-module Separation DistanceMethodology &
Analysis
Dynamic Lifecycle Cost1. Nonrecurring
- Manufacture and IA&T2. Initial deployment/launch3. Recurring
- Manufacture and IA&T- Operations support
300
400
500
600
700
800
900
1,600 2,000 2,400 2,800 3,200 3,600 4,000 4,400 4,800
Me
dia
n S
yst
em
Dy
na
mic
Lif
ecy
cle
Co
st (F
Y2
00
8$
M)
System Mass (kg)
Arch 1 Arch 2 Arch 4
Arch 27 Arch 7 Arch 8
Arch 10 Arch 26 Arch 13
Arch 20 Arch 22 Arch 29
Arch 25
© 2009 Massachusetts Institute of Technology Slide 10
- Operations support- Wrapper (e.g., human labor)- Ground station facilities
4. Lifecycle replenishments- Recurring (manufacture and IA&T)- Launch
900
1,000
1,100
1,200
1,300
1,400
1,500
1,600
1,700
1,800M
ed
ian
Sy
ste
m D
yn
am
ic L
ife
cycl
e C
ost
(FY
20
08
$M
)
always less massive Monolithic spacecraft are always less massive
than fractionated spacecraft +2,871 kg
+159 kg
Results: Inter-module Separation DistanceMethodology &
Analysis
+2,115 kg
Monolithic spacecraft are not necessarily less expensive than fractionated spacecraft
300
400
500
600
700
800
900
1,600 2,000 2,400 2,800 3,200 3,600 4,000 4,400 4,800
Me
dia
n S
yst
em
Dy
na
mic
Lif
ecy
cle
Co
st (F
Y2
00
8$
M)
System Mass (kg)
Arch 1 Arch 2 Arch 4
Arch 27 Arch 7 Arch 8
Arch 10 Arch 26 Arch 13
Arch 20 Arch 22 Arch 29
Arch 25
© 2009 Massachusetts Institute of Technology Slide 11
900
1,000
1,100
1,200
1,300
1,400
1,500
1,600
1,700
1,800M
ed
ian
Sy
ste
m D
yn
am
ic L
ife
cycl
e C
ost
(FY
20
08
$M
) The Dynamic Lifecycle Cost of fractionated spacecraft
increases with thenumber of modules
The Mass of fractionated spacecraft increases with the use of shared resources
The Dynamic Lifecycle Cost of fractionated spacecraft
may or may not increase with the use of shared resources
+627 kg
+333 $M
Results: Inter-module Separation DistanceMethodology &
Analysis
300
400
500
600
700
800
900
1,600 2,000 2,400 2,800 3,200 3,600 4,000 4,400 4,800
Me
dia
n S
yst
em
Dy
na
mic
Lif
ecy
cle
Co
st (F
Y2
00
8$
M)
System Mass (kg)
Arch 1 Arch 2 Arch 4
Arch 27 Arch 7 Arch 8
Arch 10 Arch 26 Arch 13
Arch 20 Arch 22 Arch 29
Arch 25
+6 $M+20 kg
-136 $M-87 $M+53 kg
© 2009 Massachusetts Institute of Technology Slide 12
+284 kg
900
1,000
1,100
1,200
1,300
1,400
1,500
1,600
1,700
1,800M
ed
ian
Sy
ste
m D
yn
am
ic L
ife
cycl
e C
ost
(FY
20
08
$M
) The Dynamic Lifecycle Cost of fractionated spacecraft
increases with thenumber of modules
The Mass of fractionated spacecraft increases with the number of modules
+171 $M
+140 kg
+357 $M
Results: Inter-module Separation DistanceMethodology &
Analysis
+280 kg
300
400
500
600
700
800
900
1,600 2,000 2,400 2,800 3,200 3,600 4,000 4,400 4,800
Me
dia
n S
yst
em
Dy
na
mic
Lif
ecy
cle
Co
st (F
Y2
00
8$
M)
System Mass (kg)
Arch 1 Arch 2 Arch 4
Arch 27 Arch 7 Arch 8
Arch 10 Arch 26 Arch 13
Arch 20 Arch 22 Arch 29
Arch 25
© 2009 Massachusetts Institute of Technology Slide 13
MMD - (1) number of modes, (2) number of dominant modes,
Multimodal Distribution (MMD)
Normal Distribution (ND)
Results: Confidence in Dynamic LCCMethodology &
Analysis
Spacecraft Cost Modeling
Spacecraft Dynamic Lifecycle Cost Distribution
ND - Mean
MMD – Median, Mean, or Mode
Measure of Variability (due to distribution)
ND - Variance
Dynamic Lifecycle
Value
Measure of Central Tendency
(2) number of dominant modes, (3) skewness, (4) kurtosis, and (5) order statistic, five-number summary (aka box-and-whisker plot)
Measure of Variability (due to CERs)
Value
Percentage confidence levels
© 2009 Massachusetts Institute of Technology Slide 14
(5) order statistic, five-number summary (aka box-and-whisker plot)
Results: Confidence in Dynamic LCCMethodology &
Analysis
Spacecraft Cost Modeling
MMD – Median
Measure of Variability (due to distribution)
Measure of Variability (due to CERs)
Measure of Central Tendency
Percentage confidence levels
© 2009 Massachusetts Institute of Technology Slide 15
1,100
1,200
1,300
1,400
1,500
1,600
1,700
1,800
1,900
Dy
na
mic
Lif
ecy
cle
Co
st (
FY
20
08
$M
)
6.36 8.06 8.22 8.30 8.96
Results: Confidence in Dynamic LCCMethodology &
Analysis
300
400
500
600
700
800
900
1,000
1 2 3 4 5
Dy
na
mic
Lif
ecy
cle
Co
st (
FY
20
08
$M
)
Spaceraft Architecture
Arch 1 Arch 2 Arch 4 Arch 27 Arch 10
+44.91-90.73 -41.71
+168.95
Two-Module
Monolithic
Spacecraft
Three-
Module© 2009 Massachusetts Institute of Technology Slide 16
1,100
1,200
1,300
1,400
1,500
1,600
1,700
1,800
1,900
Dy
na
mic
Lif
ecy
cle
Co
st (
FY
20
08
$M
)
6.36 8.06 8.22 8.30 8.96
Fractionated spacecraft can have inter-quartile ranges encapsulated by monolithic
inter-quartile ranges
Results: Confidence in Dynamic LCCMethodology &
Analysis
300
400
500
600
700
800
900
1,000
1 2 3 4 5
Dy
na
mic
Lif
ecy
cle
Co
st (
FY
20
08
$M
)
Spaceraft Architecture
Arch 1 Arch 2 Arch 4 Arch 27 Arch 10
+44.91-90.73 -41.71
+168.95
Two-Module
Monolithic
Spacecraft
Three-
Module© 2009 Massachusetts Institute of Technology Slide 17
1,100
1,200
1,300
1,400
1,500
1,600
1,700
1,800
1,900
Dy
na
mic
Lif
ecy
cle
Co
st (
FY
20
08
$M
)
6.36 8.06 8.22 8.30 8.96
Results: Confidence in Dynamic LCCMethodology &
Analysis
Certain fractionated spacecraft demonstrate to have less cost “risk” than comparable monolithic spacecraft
300
400
500
600
700
800
900
1,000
1 2 3 4 5
Dy
na
mic
Lif
ecy
cle
Co
st (
FY
20
08
$M
)
Spaceraft Architecture
Arch 1 Arch 2 Arch 4 Arch 27 Arch 10
+44.91-90.73 -41.71
+168.95
Two-Module
Monolithic
Spacecraft
Three-
Module© 2009 Massachusetts Institute of Technology Slide 18
1,100
1,200
1,300
1,400
1,500
1,600
1,700
1,800
1,900
Dy
na
mic
Lif
ecy
cle
Co
st (
FY
20
08
$M
)
6.36 8.06 8.22 8.30 8.96
Results: Confidence in Dynamic LCCMethodology &
Analysis
but fractionated spacecraft can be 950 $M more
expensive than monolithic spacecraft
Fractionated spacecraft can be up to 104 $M less than comparable monolithic spacecraft...
300
400
500
600
700
800
900
1,000
1 2 3 4 5
Dy
na
mic
Lif
ecy
cle
Co
st (
FY
20
08
$M
)
Spaceraft Architecture
Arch 1 Arch 2 Arch 4 Arch 27 Arch 10
+44.91-90.73 -41.71
+168.95
Two-Module
Monolithic
Spacecraft
Three-
Module© 2009 Massachusetts Institute of Technology Slide 19
• Problem Formulation
• Methodology & Analysis
• Synthesis
• Conclusion
Agenda
• Conclusion
© 2009 Massachusetts Institute of Technology Slide 20
System (Aggregate) Mass and Shared Subsystem Resources• System mass increases
• With increase in the use of shared resources• With increase in the number of modules via system-wide redundancy
NRE and RE Costs• Dynamic Lifecycle Cost is dependent on NRE and RE costs
• NRE and RE costs correlate positively with mass
Number and Cost of Replenishments
Key Lessons LearnedSynthesis
Number and Cost of Replenishments• Aggregate number of replenishments increases with number of modules
• Aggregate cost of replenishments increases
Launch Vehicle Usage and Costs• Fractionation decouples subsystems and payloads into modules
• New spacecraft deployment strategies• Fractionated spacecraft may fit into a smaller launch vehicle orset of smaller launch vehicles• Reduces the launch costs (significantly)
© 2009 Massachusetts Institute of Technology Slide 21
Mass: monolithic spacecraft are less massive than fractionated spacecraft• Number of modules and shared resource usage
Dynamic Lifecycle Cost: monolithic spacecraft are less expensive than fractionated spacecraft. Fractionated spacecraft have higher...
• Number of modules and shared resource usage• System mass (and size)
• NRE and RE costs• Launch costs
• Aggregate number of replenishments
Fundamental Reason for Selected TrendsSynthesis
• Aggregate number of replenishments• Aggregate cost of replenishments (launch + RE costs)
Dynamic Lifecycle Cost: monolithic spacecraft are more expensive than fractionated spacecraft. Fractionated spacecraft have higher...
• Number of modules and shared resource usage• System mass (and size)
• NRE and RE costs• Aggregate number of replenishments
Fractionated spacecraft have lower...• Aggregate cost of replenishments (due to launch costs)
© 2009 Massachusetts Institute of Technology Slide 22
• Problem Formulation
• Methodology & Analysis
• Synthesis
• Conclusion
Agenda
• Conclusion
© 2009 Massachusetts Institute of Technology Slide 23
Are Fractionated Spacecraft Viable?Conclusion
Are fractionated spacecraft a suitable, if not “better”, alternative to monolithic spacecraft in the current spacecraft paradigm?
Monolithic Fractionated
Mission Type Spacecraft Type
Context
Remote Sensing Mission
Launch, Technical, Environmental, Operational
Pointing-Intensive~36 mas pointing tolerance
Lifecycle Uncertainties(O’Neill, 2009)
Mass
A Fractionated SpacecraftSource: DARPA
LifecycleCost
LifecycleCost
Value Proposition
Value Proposition
GEOEye-1Source: GEOEye
Monolithic Spacecraft
Fractionated Spacecraft
© 2009 Massachusetts Institute of Technology Slide 24
Are Fractionated Spacecraft Viable?Conclusion
Are fractionated spacecraft a suitable, if not “better”, alternative to monolithic spacecraft in the current spacecraft paradigm?
Monolithic Fractionated
Mission Type Spacecraft Type
Context
Remote Sensing Mission
Launch, Technical, Environmental, Operational
Pointing-Intensive~36 mas pointing tolerance
Lifecycle Uncertainties(O’Neill, 2009)
Mass
+159 kg+2,871 kg A Fractionated Spacecraft
Source: DARPA
LifecycleCostValue
PropositionMass
GEOEye-1Source: GEOEye
Monolithic Spacecraft
Fractionated Spacecraft
© 2009 Massachusetts Institute of Technology Slide 25
Are Fractionated Spacecraft Viable?Conclusion
Are fractionated spacecraft a suitable, if not “better”, alternative to monolithic spacecraft in the current spacecraft paradigm?
Monolithic Fractionated
Mission Type Spacecraft Type
Context
Remote Sensing Mission
Launch, Technical, Environmental, Operational
Pointing-Intensive~36 mas pointing tolerance
Lifecycle Uncertainties(O’Neill, 2009)
-104 $M+950 $M
Mass
A Fractionated SpacecraftSource: DARPA
LifecycleCost
LifecycleCost
GEOEye-1Source: GEOEye
Monolithic Spacecraft
Fractionated Spacecraft
© 2009 Massachusetts Institute of Technology Slide 26
O'Neill, M. G. (2009). Assessing the Impacts of Fractionation on Pointing-Intensive Spacecraft. SM Thesis, Aeronautics and Astronautics, Massachusetts Institute of
Technology. www.seari.mit.edu
AddressedInclude other cardinal measures of effectiveness in the Value Proposition
What about the benefits of fractionation?• Analysis of the mission lifetime benefits of fractionation
Further Exploration of the Value Proposition
DiscussedInvestigate alternative wireless power distribution systems
• Radically change the value proposition• Radio and microwave power transmission(O’Neill, 2009; Kerslake, 2008)
• Laser power beaming(O’Neill, 2009; Kerslake, 2008)
• Concentrated, reflected sunlight(Turner, 2006)
• Electromagnetic formation flight (EMFF) (MIT Space Systems Lab)
What about other benefits of fractionation?• Remote sensing mission, fractionated spacecraft interferometers
© 2009 Massachusetts Institute of Technology Slide 27
ReferencesO'Neill, M. G. (2009). Assessing the Impacts of Fractionation on Pointing-Intensive Spacecraft. SM Thesis,
Aeronautics and Astronautics, Massachusetts Institute of Technology.
Kerslake, T. W. (2008). Lunar Surface-to-Surface Power Transfer. In University of New Mexico's Institute for Space and Nuclear Power Studies: Space Technology and Applications International Forum. Albuquerque, New Mexico.
Turner, A. E. (2006). Power Transfer for Formation Flying Spacecraft. In American Institute of Astronautics and Astronautics: Space 2006 Conference and Exposition. San Jose, California.
© 2009 Massachusetts Institute of Technology Slide 28
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