The document outlines a proposal for a conceptual interplanetary cubesat mission to Mercury, aiming to investigate surface volatiles in polar regions while utilizing a systems engineering process. Key components of the project include mission objectives, timelines, top-level requirements, alternative architectures, and risk mitigation strategies. The approach emphasizes cost-effectiveness and the timely completion of planetary science missions due to constraints on NASA's funding and resources.

1. Applying the Systems Engineering Process
to a Conceptual Mercury CubeSat Mission
Author: Karen Grothe
karen@karengrothe.com
Advisor: Dr. Bohdan Oppenheim, Loyola Marymount University
Bio:
• BS in EE from Washington University in St. Louis
• Astronautical Engineering Certificate from UCLA Extension
• MS in Systems Engineering from Loyola Marymount University
• 16 years experience in aerospace as a systems engineer at McDonnell
Douglas, Boeing, and Raytheon
• Leveraging experience managing requirements and verification testing
for airborne systems into a stellar career advancing spacecraft systems.

2. Overview
• Mission objectives
• Stakeholders
• Mission timeline
• Top-level requirements
• Alternative mission
architectures
• Concept of operations
• System drivers and key
requirements
• Trade studies
• Propulsion
• Communications
• Mission utility
• Mission risks and mitigation
• Baseline mission concept
and architecture
• Proposed subsystem block
diagrams
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
24/30/2016
This project uses a systems engineering process to propose a
conceptual interplanetary CubeSat mission to gather science
data at Mercury’s poles.

3. The Decadal Survey
In 2011, the National
Academy of Sciences
released Vision and
Voyages for Planetary
Science in the Decade
2013 – 2022 outlining
science priorities for
NASA’s planetary science
missions.
4/30/2016
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
3
Image source: http://solarsystem.nasa.gov/2013decadal/

4. Space Missions Are Expensive
NASA Funding Limits the Number of Missions
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
4/30/2016 4

5. NASA’s Planned Interplanetary CubeSat
Missions
Auxiliary Payload on Europa Mission
(2020s)
MarCO
(Secondary Payload with Mars INSIGHT)
Lunar Flashlight (July 2018)
NEA Scout (July 2018)
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
4/30/2016 5

6. Methodology:
Space Mission Engineering Process
1. Define Broad (Qualitative) Objectives and Constraints
2. Define Principal Players (Stakeholders)
3. Define Program Timescale
4. Estimate Quantitative Needs, Requirements, and
Constraints
5. Identify Alternative Mission Architectures
6. Identify Alternative Mission Concepts
7. Identify Likely System Drivers and Key Requirements
8. Conduct Performance Assessments and System
Trades
9. Evaluate Mission Utility
10. Define Baseline Mission Concept and Architecture
11. Revise Quantitative Requirements and Constraints
12. Iterate and Explore Other Alternatives
13. Define System Requirements
14. Allocate Requirements to System Elements
This project covers
the first ten steps of
the 14-step Space
Mission Engineering
Process presented
in Space Mission
Engineering: The
New SMAD.
Image Source: http://www.sme-smad.com/index.asp
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 6

7. Mission Objectives and Constraints (Step 1)
Proposed Mercury CubeSat Mission Statement
After the success of the
MESSENGER spacecraft in
mapping Mercury, planetary
scientists have more questions
about Mercury, but the expense
of a large mission means that it
may be many years before
another mission to Mercury is
undertaken. The United States
needs a less expensive class
of spacecraft to perform such
planetary science in a more
timely fashion.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie
Institution of Washington
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
4/30/2016 7

8. Mission Objectives and Constraints (Step 1)
Proposed Mercury CubeSat Mission Objectives
•Primary Objective: To
investigate the state,
extent, and chemical
compositions of surface
volatiles in the polar
regions of Mercury
•Secondary Objective: To
demonstrate the
functionality of small
spacecraft designed to the
CubeSat standard in
planetary exploration
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie
Institution of Washington/National Astronomy and Ionosphere Center, Arecibo
Observatory
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 8

9. Stakeholders (Step 2)
• NASA – Determines science objectives with NSF; manages
spacecraft development and operates spacecraft
• NSF – Determines science objectives with NASA and provides
funding for scientific investigations
• Federal Government – Provides funding for NASA and NSF
• Suppliers – Tyvek, Vacco, launch provider, etc.
• Universities – Prime Investigators (PIs) and partners with
NASA and NSF
• Scientists – End users of data returned from mission
• Community – Educators and the general public benefit from
scientific findings
• Media – Disseminates announcements from NASA, NSF,
Federal Government, Universities, and Scientists.
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 9

10. Mission Timeline (Step 3)
Phase End Defined By Duration
Typical Duration *
(Small Program)
Concept Exploration
Start of tech. funding; preliminary
requirements release 3 months 1-6 months
Detailed Development
Risk Reduction/Technology
Development Start of program funding 3 - 6 months 0 - 12 months
Detailed Design and
Development Formal requirements release 6 months 2 - 12 months
Production and Deployment
Production Ship to Launch Site 6 months 6 - 24 months
Launch Lift-Off and Arrival in LEO 1 month 1 month
On-Orbit Checkout/Transfer
to Operational Orbit Start of operations 6 years
Up to 10 years
interplanetary
Operations and Support
Operations
Spacecraft dies or decision to be
put to sleep 1+ years 1 month - 5 years
Disposal Re-entry or turn-off 0 years 0 - 5 years
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
10
* Typical Durations come from SME-SMAD [14, Table 3-3, Page 54]
4/30/2016

11. Top-Level Requirements Summary (Step 4)
1. Spacecraft payload shall be appropriate to investigate surface
volatiles in the polar regions of Mercury.
2. Spacecraft shall fit into 12U CubeSat size specification.
3. Spacecraft lifetime shall be at least 8 years.
4. Spacecraft shall be capable of communicating with Earth from
Mercury’s orbit.
5. Thermal management shall protect components from the
extreme temperatures present near Mercury.
6. Spacecraft shall be capable of providing power and fault
protection to sensor payload.
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 11

12. Alternative Mission Architectures (Step 5)
• Operational views
• OV-1: Overview
• System views
• SV-1: System Interface Description (for two
options)
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 12

13. K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
13
Space Flight
Operations Facility
Deep Space
Network
Users/CustomersPasadena, CA
Launch
Mercury CubeSat
Mission Architecture
Overview
CubeSat
Image Credit: Tomas Svitek
4/30/2016

14. Mercury CubeSat Mission
System Interface Description (Option A)
14
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016

15. Mercury CubeSat Mission
System (with Relay) Interface Description (Option B)
15
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016

16. Concept of Operations (Step 6)
Launch and Trajectory
• Launch as a
secondary payload
• Take a trajectory
similar to that of the
MESSENGER
spacecraft
• Orbit insertion at
Mercury in about 6
years Example trajectory: MESSENGER
Image source: http://messenger.jhuapl.edu/the_mission/trajectory.html
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 16

17. Mercury CubeSat Concept of Operations
(Step 6)
 Mission Timeline/Schedule (The overall schedule for planning,
building, deployment, operations, replacement, and end-of-life) – 1
spacecraft developed over 2 years, launched in the earliest available
window, operates for 8 years.
 Tasking, Scheduling & Control (How the system decides what to do
in the long term and short term) – Single mission operations center
 Communications Architecture (How the various components of the
system talk to each other) – Space/Ground: Either direct downlink to
Deep Space Network or relayed to Earth via nearby spacecraft;
Ground/User: Internet distribution
 Data Delivery (How mission and housekeeping data are generated or
collected, distributed & used) – Sensor data and spacecraft health and
orbit/attitude data sent to ground and distributed to users
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 17

18. System Drivers and Key Requirements
(Step 7)
• Mass and power are typical spacecraft system
drivers.
• Using the CubeSat standard adds the volume that
subsystems occupy as a constraint.
• Thermal environment: Temperature at Mercury
ranges from 80 K to 700 K
• Spacecraft lifetime of 8 years
4/30/2016
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
18

19. Proposed Mass, Volume, and Power Budget
System Description Heritage
Mass
(kg)
Volume
(U)
Power (W)
(Peak)
ADCS
Star tracker, sun sensor,
reaction wheels, IMU
BCT XACT (star trackers, IMU), sun sensor,
reaction wheels 1 1 3
Propulsion Microthrusters Busek electrospray thrusters 1 1 30
C&DH/
Processing
Science & Engrg.
Management, processing SpaceCube Mini, Lunar Ice CubeSat 0.5 0.5 5
Thermal/
Radiation
Passive shielding, passive
cooling, heaters, sun shield
MESSENGER's sunshade and other thermal
defense 3 2 8
Structures/
Mechanisms
Frame, deployer, deployables
(gimballed, stowed solar
panel array, antennas)
Planetary Systems Corp. 12U deployer, MMA
Design Ehawk gimballed solar panels 8 - 1
Comm Antenna, transceiver
SERC's deployable high gain antenna, JPL's
IRIS X-Band Radio 3.5 2.5 10
Power
Electrical system, conversion,
regulation, batteries 1.5 1.5 5
Payload:
Near Infrared
Spectrometer
Detector, optics, associated
electronics, cryocooling
JPL Lunar Flashlight's spectrometer, Lunar
IceCube's Broadband InfraRed Compact High
Resolution Explorer Spectrometer (BIRCHES),
Moon Mineralogy Mapper 2.5 1.5 7
Laser Altimeter
Optics, associated electronics,
cryocooling (If required)
JPL Lunar Flashlight's laser, MESSENGER
Laser Altimeter (MLA) 4 2 14
Total without propulsion 25 12 83
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 19

20. Performance Assessments and Trade
Studies (Step 8)
Trade studies:
4/30/2016
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
20
Credit: NASA Jet Propulsion Laboratory Image Credit: USC
Propulsion Communications

21. Performance Assessments & Trade Studies (Step 8)
Measures of Effectiveness
• The following measures of effectiveness are used to
evaluate propulsion, power, and communications
alternatives:
• Technology Readiness Level (TRL)
• Performance specifications
• Propulsion: Thrust, Isp, and power required
• Communications: Data rate and power required
• Mass
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 21

22. Performance Assessments & Trade Studies (Step 8)
Propulsion Alternatives
1. VACCO Propulsion Unit for CubeSats –
a COTS propulsion system which
includes a warm gas thruster
2. CubeSat Ambipolar Thrusters (CAT)
3. HYDROS™ Water Electrolysis Thruster
4. Solar sail
5. Solar Electric Power/Solar Electric
Propulsion (SEP^2)
6. Colloidal Thruster, a.k.a. electrospray
thruster
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
4/30/2016 22
Image Sources: 1. VACCO Industries
2. http://pepl.engin.umich.edu/thrusters.html
3. Tethers Unlimited, Inc.
4. NASA
6. Busek Co., Inc.
No
picture
available
1
2
3
4
5
6

23. Propulsion Trade Study
Alternative Measures of Effectiveness Comments
TRL Thrust Isp Power Mass
VACCO
Propulsion Unit
for CubeSats
TRL-7+ 5.4 mN 70 s 15 W < 1 kg Includes Warm Gas
Thruster, Useful for
attitude control
CubeSat
Ambipolar
Thruster
TRL-3 ≤ 2 mN Up to 2000 s
(About 800 s
in July 2015
tests with
Xenon ions)
≤ 10 W ≤ 1 kg Flexible propellant
(water or iodine,
ideally); first launch
planned for early 2017
HYDROS™ Water
Electrolysis
Thruster
TRL-5
(Expected to
mature to TRL-6
Winter 2015)
≤ 1 N 300 s Water propellant;
“green”
Solar sail TRL-5 < 7mN 4 – 10 kg
(NanoSail-D
was ~ 4 kg)
Thrust from solar
pressure on sail
Solar Electric
Power/Solar
Electric
Propulsion
(SEP^2)
TRL-3 (est.) TBD by
mfr.
Up to 3000 s Generates
80 W,
20 W when
thrusting
TBD Xenon propellant;
System comes with solar
panels
Colloidal
(Electrospray)
Thruster
TRL-7+
TRL-5
100 µN
≤ 1 mN
2300 s
400 s to
> 1300 s
5 W
15 W
320 g (wet)
1.15 kg
Busek has delivered
100-µN thrusters to
NASA
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
4/30/2016 23

24. Performance Assessments & Trade Studies (Step 8)
Communications Alternatives
1. Laser communication
2. Direct microwave
communication with
deployable high-gain
antenna
3. Integrated Solar Array &
Reflectarray Antenna
4. Using a relay spacecraft
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
4/30/2016 24
Image Sources:
1. NASA
2. USC
3. NASA
4. ESA
1
2
3
4

25. Communications Trade Study
Alternative Measures of Effectiveness Comments
TRL Data Rate Power Used Mass
Laser
Communication
TRL-6 < 625 Mbps to <
2.88 Gbps
40 – 50 kbps from
2 AU
50 – 140 W
(LADEE)
0.5 W average
30 kg
(LADEE)
Optical receiver
required; LADEE
transmitter is too
heavy
Direct Microwave
Communication
with Deployable
High Gain Antenna
X: TRL-9
K: TRL-3 to
TR-9
Antenna:
TRL-6 to
TRL-9
X: < 500 Mbps
Ka: < 3 Gbps
Ku: <150 Mbps
K: < 1.2 Gbps
X: < 90–120 W
Ka: N/A
Ku: 47 W
K: 30 W
X: ≤ 4 kg
Ka: 2.7 kg
Ku: 2.3 kg
K: 2.8 kg
JPL-developed IRIS
X-band radio is
specifically
designed for
CubeSats
Integrated Solar
Array & Reflectarray
Antenna
TRL-5
(Flying in
2016 to
raise to
TRL-7)
≥ 100 Mbps No more than
system with
deployable
parabolic antenna
Minimal
difference
from
deployable
parabolic
antenna
High Bandwidth
Ka-band, high gain
antenna integrated
into COTS solar
array
Relay Spacecraft TRL-9 Possibility:
BepiColombo or
Akatsuki
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 25

26. Evaluating Mission Utility (Step 9)
4/30/2016
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
26
How much
will it cost?
Is the mission
worthwhile?
How much
meaningful
science data
can we collect?
What are
the risks?

27. Mission Risks and Mitigation
Mission Risks Mitigation
1. Launch delays Have a secondary launch
date
2. Communication failure Testing; plan an alternative
communication path or
redundancy
3. Radiation environment causing failure Ruggedize; use shielding
4. Collision with space debris or another
spacecraft
No mitigation
5. Technology readiness lacking Use technology already in
development; fly technology
that is not less than TRL 5
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 27

28. Mission Risk Matrix
Very Low Low Medium High Very High
Very High
High
Medium
Low
Very low
Likelihood
Impact
2
1
35
4
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 28
Risks:
1. Launch delays
2. Comm. failure
3. Radiation env.
causes failure
4. Collision
5. TRL

29. Baseline Mission Concept and Architecture (Step 10)
Top Level Spacecraft Block Diagram
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission 29
Command and Data Handling
Subsystem
Electrical Power Subsystem
Attitude Determination &
Control Subsystem
Communications
Subsystem
Payload Subsystem
Propulsion Subsystem
Thermal Control Subsystem
Solar
Array
Battery
S/C
Ground
Power
Mgmt.
Ckts.
Power
Distrib.
Module
Battery
Charge
Reg. To Other
Subsystems
On-Board Data Storage
On-Board Computer (OBC)
Commands to
Subsystems
Data
Handling
Function
ADCS
Function
Command
Function
X-Band
Transceiver
Deployable
Antenna
Mission Data
Star
Trackers
Sun
Sensors
IMU
Reaction
Wheels
Infrared
Spectrometer
Commands
from OBC
Data to OBC
HeatersRadiatorsHeat Pipes Coatings Multi-Layer Insulation
Commands
from Earth
Ionic
Liquid
Propellant
Electrospray Thrusters
Sun Shield
Commands to Thrusters
Laser
Altimeter
Flow Control
Valve
Commands
from OBC
4/30/2016

30. Conclusion
• Payload Possibilities:
• Near infrared spectrometer
• Laser to illuminate shadowed
craters
• Altimeter capability would allow
mapping spectrometer data to depth
within craters
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
304/30/2016
Example Instrument
JPL’s NanoSat Spectrometer
Example of illuminating shadowed crater with laser
Images source: NASA (both)
By drawing upon interplanetary CubeSat projects now in
progress at NASA and on lessons learned during the
MESSENGER mission, an interplanetary CubeSat mission to
Mercury could be developed in about two years.

31. References
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Decade 2013 - 2022, Washington D.C.: National Academies Press, 2011.
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K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 31

32. References
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Ranging - Mission Design', 2015. [Online]. Available:
http://messenger.jhuapl.edu/the_mission/mission_design.html [Accessed: 01- Nov- 2015].
• [32] Messenger.jhuapl.edu, 'MESSENGER: MErcury Surface, Space ENvironment, GEochemistry, and
Ranging - The Payload Instruments', 2015. [Online]. Available:
http://messenger.jhuapl.edu/instruments/index.html [Accessed: 01- Nov- 2015].
• [33] Messenger.jhuapl.edu, 'MESSENGER: MErcury Surface, Space ENvironment, GEochemistry, and
Ranging - Working from Orbit', 2015. [Online]. Available: http://messenger.jhuapl.edu/the_mission/orbit.html
[Accessed: 01- Nov- 2015].
K. Grothe – Applying a Systems Engineering Process to
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35. Supplemental Slides
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
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4/30/2016

36. CubeSat History
1999
• CubeSat
concept
defined
2003
• First flight –
university
CubeSats
2006
• First NASA
CubeSat –
GENESAT
2007
• First CubeSat
launched by
commercial
company
(Boeing)
2013
• First USAF SMC
CubeSats
launched
• First PlanetLabs
Doves
launched
2015
• 101st
PlanetLabs
Dove launched
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 36

37. CubeSat Mission Types By Year
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission4/30/2016 37
NumberLaunched
Year

38. Ground Segment
JPL’s Space Flight
Operations Facility Deep Space Network
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission 38
(Source: NASA/JPL-Caltech)
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39. Launch Segment
• CubeSat Mercury
Mission shall launch as a
secondary payload.
• A Canisterized Satellite
Dispenser (CSD) will be
used to encapsulate the
spacecraft on the launch
vehicle and dispense it
on an appropriate Earth
orbit.
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission 39
Images Source: Planetary Systems Corporation
4/30/2016

40. Payload
Driving Requirements
• Scientific objectives
• Investigate the state, extent, and chemical compositions of
surface volatiles in the polar regions of Mercury
• Thermal environment
• Small size
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
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41. Electrical Power Subsystem
•Design Drivers
• Orbit: Mercury orbit requires enough battery power to
supply the spacecraft power during eclipse.
• Payload requirements: Instruments require power, fault
protection, bursts of power when imaging a particular
commanded area.
• Distribute power to all subsystems
• Spacecraft lifetime of 8 years
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
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4/30/2016

42. Communication Subsystem
Driving Requirements
• Distance of the mission from Earth
• Pointing requirements
• Small size of satellite
• Power availability
• Thermal control
• Telemetry and sensor data downlinked at X-band
• In the range 8400 - 8450 MHz for DSN
• Commands uplinked at X-band
• In the range 7145 - 7190 MHz for DSN
• Data rate – If the data rate is too slow, data storage
capability will need to increase.
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
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4/30/2016

43. Attitude Determination & Control
Subsystem (ADCS)
Driving Requirements
• Three-axis stabilization
• Power: Solar panels need to point to the sun to
produce sufficient power
• Pointing accuracy necessary to complete the
science objectives
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
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4/30/2016

44. Thermal Control Subsystem
Driving Requirements
• Thermal Environment: Orbiting Mercury presents
extreme temperatures as the spacecraft moves
between eclipse and sun exposure
• Large thermal effect from sunlight reflected up from
Mercury
• Infrared heat emanating from the planet's
scorching day-side surface
• Spacecraft size
• Instruments may need extra thermal control
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
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4/30/2016

45. Propulsion Subsystem
Driving Requirements
•Distance to destination
•Fuel
•Influence on weight and size
•High performance  less weight
•Spacecraft lifetime of 8 years
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a Conceptual Mercury CubeSat Mission
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46. Proposed Payload Block Diagram
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
46
Infrared Spectrometer Laser Altimeter
Command & Data Handling Subsystem
Commands Commands DataData
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47. Proposed Electrical Power Subsystem Block Diagram
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
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Solar
Panel 3
Solar
Panel 2
Solar
Panels
Power
Management
Circuits
Spacecraft
Ground
Battery Charge
Regulator
Spacecraft
Battery
Power
Distribution
Module
Attitude
Determination
& Control
Subsystem
Communications
Subsystem
Payload
Thermal
Control
Subsystem
Command &
Data Handling
Subsystem
Power Subsystem Architecture
(Simplified)
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48. Proposed Communication Subsystem
Block Diagram
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
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Command & Data
Handling Subsystem
X-Band
Transponder
Deployable
High Gain
Antenna
Commands
Telemetry Inputs Mission Data
Commands
from Earth
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49. Proposed ADCS Block Diagram
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
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On-Board Computer
ADCS Function
Sun
Sensors
Star
Trackers
Attitude
Determination
Attitude
Control
Reaction
Wheels
IMU
Thrusters
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50. Proposed Propulsion Subsystem
Block Diagram
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
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Ionic Liquid
Propellant
Flow Control
Valve
Electrospray Thrusters
Command & Data
Handling
Subsystem
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51. Diagram of
Proposed Thermal Control Subsystem
K. Grothe – Applying a Systems Engineering Process to
a Conceptual Mercury CubeSat Mission
51
Coatings
Radiators Multi-Layer
Insulation
Blankets
Heat Pipes
Sun Shield
Heaters
Dimensions in mm
12U CubeSat Payload Spec Source:
http://www.planetarysystemscorp.com/web/wp-content/uploads/2015/08/2002367C-Payload-Spec-for-3U-6U-12U-27U1.pdf
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52. Additional Possibilities
• MBSE: Project could be further developed using the
CubeSat SysML model developed by the INCOSE
Space Systems Working Group
• Interplanetary CubeSats in constellations
• Interplanetary CubeSats inserted in the orbit of a
planetary body from a mothership
• Weight reduction:
• Wireless intra-spacecraft communication
• Eliminate black boxes and create an optimized design
K. Grothe – Applying a Systems Engineering Process to
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