1. T I T A N
E L E C 9 7 6 2 : P R O J E C T
Meiyappan Muthu z5026869
Hassan Wahab z5025960
Cheng Wei z5036213
Jason Chan z3256518

2. Contents
1. Executive Summary...............................................................................................................................1
2. Background ...........................................................................................................................................2
2.1 Historical observations and explorations .............................................................................................2
2.2 Unanswered Questions about Titan ....................................................................................................3
3. Mission Statement.................................................................................................................................5
3.1. Mission Statement..............................................................................................................................5
3.2. Mission Objectives .............................................................................................................................5
4. Stakeholders .........................................................................................................................................6
5. Timeline.................................................................................................................................................7
6. System Concept....................................................................................................................................8
7. Concept of Operations...........................................................................................................................9
8. Requirements......................................................................................................................................11
9. System Architecture ............................................................................................................................16
9.1. Launch Vehicle ................................................................................................................................16
9.2. Orbits and Trajectories.....................................................................................................................16
9.3. Payloads ..........................................................................................................................................17
9.4. Subsystems .....................................................................................................................................21
9.4.1. Command and Data Handling Subsystem (CDHS)....................................................................21
9.4.2. Structural Subsystem.................................................................................................................22
9.4.3. Attitude Determination and Control Subsystem (ADCS) ............................................................23
9.4.4. Power Subsystem......................................................................................................................23
9.4.5. Thermal Subsystem...................................................................................................................25
9.4.6. Communications Subsystem .....................................................................................................26
9.4.7. Propulsion Subsystem ...............................................................................................................27
9.5. Ground Architecture.........................................................................................................................27
10. Propulsion Subsystem Analysis .......................................................................................................30
10.1 Statement of Works.........................................................................................................................30
10.2 Fault Tree Analysis .........................................................................................................................32
10.3. Preliminary Failure Mode, Effects and Criticality Analysis (FMECA)...............................................34
10.4. Risk Matrix .....................................................................................................................................37
11. Conclusion............................................................................................................................................38
Appendix ....................................................................................................................................................39
References.................................................................................................................................................40

3. List of Figures
Figure 1: Titan as observed by Pioneer 11 ...................................................................................................2
Figure 2: Titan as observed by Voyager 1 ....................................................................................................2
Figure 3: Titan as observed by Cassini.........................................................................................................3
Figure 4: The first images from the Huygens probe during descent ..............................................................4
Figure 5: Mission timeline diagram ...............................................................................................................7
Figure 6: Titan boat concept .........................................................................................................................8
Figure 7: Titan Boat profile views..................................................................................................................8
Figure 8: Landing operations for the Huygens probe which the Titan Boat will largely mirror........................9
Figure 9: Map of Ligeia Mare on which science operations will be conducted............................................10
Figure 10: Function tree for the Titan Boat Project......................................................................................11
Figure 11: Function block diagram for landing on Titan...............................................................................14
Figure 12: Function block diagram for mission operations ..........................................................................14
Figure 13: Functional matrix: Requirements vs. subsystem as used for subsystem design ........................15
Figure 14: Trajectory to Saturn (Labreton et al. 2002. Edited to remove dates) ..........................................16
Figure 15: Orbit around Titan (Labreton et al. 2002. Edited to remove dates).............................................17
Figure 16: Example of a twin camera system on the Mars Curiosity Rover.................................................18
Figure 17: Sample Analysis payload for the Mars Curiosity mission ...........................................................18
Figure 18: Gas collector payload used on the Huygens probe....................................................................19
Figure 19: How environmental sensors can be mounted on the mast.........................................................19
Figure 20: Mounting locations for payload systems on the Titan Boat (based on Huygens configuration)...20
Figure 21: Subsystem block diagram..........................................................................................................21
Figure 22: Titan Boat Subsystem interface N2 diagram..............................................................................21
Figure 23: The Huygens probe outer structure from which the Titan boat will draw heavilty upon..............23
Figure 24: MMRTG unit used on Mars Curiosity Rover...............................................................................24
Figure 25: Space mission power sources from AERO9500 lecture slides, week 3......................................24
Figure 26: The Huygens front shield design which the Titan Boat will reuse...............................................26
Figure 27: Example of electric boat propulsion unit from Volt master..........................................................27
Figure 28: Ground architecture for the Dawn Mission on which the Titan Boat Mission is based ................28
Figure 29: Requirements for Propulsion subsystem....................................................................................31
Figure 30: Fault Tree Analysis: operational but inaccurate direction ...........................................................33
Figure 31: Fault Tree Analysis: Operational but less thrust than expected..................................................33
Figure 32: Fault Tree Analysis: Non-operational.........................................................................................34
List of Tables
Table 1: Science objectives and the payloads used to investigate................................................................5
Table 2: Other mission stakeholders.............................................................................................................6
Table 3: Mission timeline description ............................................................................................................7
Table 4: Operational Requirements and Limits/Constraints ........................................................................12
Table 5: Function Matrix for the Titan Boat Project mapping level 2 functions ............................................15
Table 6: Summary of payloads used on the Titan Boat...............................................................................17
Table 7: Power budget estimate .................................................................................................................24
Table 8: Plutonium mass estimate..............................................................................................................25
Table 9: Failure Mode, Effects and Criticality Analysis................................................................................35
Table 10: Risk Matrix for the Titan Boat Propulsion System .......................................................................37

4. 1
1. Executive Summary
This report describes the conceptual design of a probe that will operate on the surface of Saturn’s moon,
Titan. The probe is called the Titan Boat and will cruise on the surface of Ligeia Mare, the second largest
lake on Titan, selected because it has been fully imaged by Cassini. While the Titan Boat probe will reach
Titan via an orbiter/probe configuration like Cassini-Huygens, the scope and focus of this report is
principally on the design of the surface probe itself.
The Titan Boat mission is a follow on mission to the successful Cassini-Huygens mission and aims to
further uncover the mysteries of Titan to investigate two broad scientific objectives: how conducive are
conditions on Titan to support life and what is the topology of the polar lake environment? The Titan Boat
mission will launch in late 2020 and will arrive at Titan late 2027. The Titan Boat probe will be launched via
a SpaceX Falcon 9 vehicle and will utilise a similar orbit trajectory to the Cassini-Huygens mission, sling
shotting by Venus, Earth and Jupiter. The Titan Boat’s science mission will last 100 days.
This report considers the payloads and sub-systems of the Titan Boat. The Titan Boat will utilise as much of
the heritage from the Cassini-Huygens mission as possible. The payload system, however, comprises
newer technology appropriated from the Mars Curiosity rover including cameras, spectrometers, a gas
collector and dissociator, and a host of environmental sensors. The Titan probe structure is constructed
from aluminium and will have a double storey mounting structure for the payload and subsystems. The
attitude and determination control subsystem consists of a passively designed hull structure that stabilises
the Titan boat on the liquid surface of Ligeia Mare. The Command and Data Handling Subsystem and the
Thermal Subsystem will be extremely similar to that used on the Huygens probe as these were worked very
successfully. A distinct feature of the Titan Boat is its propulsion system. Unlike the Huygens probe, the
Titan Boat will have the functionality to navigate and propel itself on the surface of Ligeia Mare using two
50W electric motors, which although small in size is sufficient for the purposes of surveying new locations.
Eight multi-mission radioisotope thermoelectric generators will power the Titan Boat.
This report also develops a statement of works to approach prime contractors to build and test the
propulsion system. A preliminary fault analysis of the propulsion system is also conducted which was
utilised to revise the design of the propulsion system into its current form. Team member contributions to
each section of the report may be found in appendix A.1.

5. 2
2. Background
2.1 Historical observations and explorations
Titan is Saturn’s largest moon. At Saturn's orbit, more than nine times farther from the sun than Earth, the
solar illumination is weak, and beneath Titan's smoggy skies it is even weaker. An observer on Titan's
surface would experience daytime as dim as deep twilight on Earth (NASA JPL n.d).
First glance of Titan
On 1 September 1979, the first artificial probe entered the Saturnian
system, Pioneer 11 visited Saturn and conducted scientific research
about its largest satellite, Titan. Pioneer 11 is a 259 kilogram deep
space scientific satellite. Its mission was to study the outer solar
system, including the asteroid belt, Jupiter and Saturn surrounding
environments, solar wind, cosmic rays and finally the boundary of the
solar system. Through temperature measurement of Titan, scientists
concluded that Titan is not likely a place for life, because its
temperature is too cold (The Pioneer Missions 2007). Pioneer 11 also
took a picture about Titan together with Saturn, but the most
significant is that it opened the door of Titan research age.
The Voyager missions
Just following Pioneer 11 footprint, Voyager 1 and Voyager 2 visited Titan in 1980 and 1981 sequentially
(Voyager the interstellar mission 2014). Voyager 1 and Voyager 2 are two deep space scientific satellite
with the same configurations, both satellites are 722 kilogram. They were launched by NASA on 5
September 1977 and 20 August 1977 to study the outer solar system and Interstellar space.
On 12 November 1980, Voyager 1 came within 6490 km distance
from Titan. During its mission, using remote sensing instruments,
Voyager 1 studied the atmospheres of Titan. Due to limited
technology, Voyager could not see through Titan’s atmospheric haze
and neither could Hubble or ground-based observations such that the
nature of the surface remained largely unknown (Lebreton et al.
2002). However, through the initial investigation of Titan, Voyager
took many valuable images and predicted that 90 percent of Titan’s
atmosphere was composed of nitrogen. It also found that the
atmosphere pressure and temperature near the Titan’s surface was
about 1.6 atmospheres and -180 degrees Celsius (Missions to Jupiter
2014).
The Cassini/Huygens Mission
In the late seventies and early eighties, NASA studied several scenarios for missions to Saturn as the next
natural step to flow the Galileo orbiter/probe mission to Jupiter. The Cassini/Huygens mission was
proposed in 1982 as a collaboration between ESA and NASA. Cassini/Huygens weighed 5650kg and was
launched on 15 October 1997 and arrived at Saturn 1 July 2004. The mission was designed to explore the
Saturnian system and all its elements: planets, moons, rings, magnetosphere and their interrelationships.
(Lebreton et al. 2002)
Cassini/Huygens scientific objectives were to determine atmospheric constituents, measure winds and
global temperatures, investigate cloud physics, determine the topography of the surface, infer internal
Figure 1: Titan as observed by Pioneer 11
Figure 2: Titan as observed by Voyager 1

6. 3
structure, investigate upper atmosphere. Huygens’s objectives are to make detailed in situ measurements
of the atmosphere structure composition and dynamics (Lebreton et al. 2002).
The Cassini-Huygens mission revealed a lot about Titan. It uncovered that Titan is rich in mixtures of
organic chemicals. The chemicals on titan are mostly nitrogen but it is mixed with methane. Titan has
mountains, dunes, rivers and lakes, but all of them are filled ethane and methane. Titan has a weather
system and seasons like earth (although the seasons are 7 earth years long).
Figure 3: Titan as observed by Cassini
2.2 Unanswered Questions about Titan
Titan has two factors that may suggest it can host the building blocks for life – a chemically active weather
cycle and liquid, both surface and potentially sub-surface.
Liquid
It is thought that Titan may have a warm and watery interior. Rogez and Lunin (2010) concluded that Titan
may have a warm hydrous silicate core overlain by a shell of high pressure ice 500-600km deep. The icy
shell might also contain a liquid layer some tens of kilometres below the surface (Beghin et al. 2010).
Norman and Fortes (2011) identify four possible areas for possible astrobiological potential: the silicate
core, subsurface ocean and crust, and surface ocean. For the purposes of this project, only two areas,
subsurface ocean and crust, and surface liquids will be considered.
1. Subsurface ocean and crust: it is thought that life could be supported if this region has liquid
ammonia given appropriate conditions (e.g. temperature, pressure, access to nutrients etc).
Methane/sulphate oceans are similar to conditions on Earth’s cold seep ocean floors. “At cold seeps,
sulphate reduction and anaerobic oxidation of methane are syntrophically linked. The metabolic
products are hydrogen sulphide and dissolved carbon ionates in liquids erupted from Titan‟s surface are
strong indications of microbial activity in the subsurface ocean.”
2. Surface liquids: Titan’s liquid surface of methane could play the same role for life that water does on
Earth. Methane based organisms, while only theoretical, has regained attention in a 2015 Cornell paper
published in Science Advances on a proof-of-concept blueprint for methane based life (Ju, 2015). It is
also thought that there may be temporary surface water, possibly unfrozen by geothermally heating
liquid methane (Fortes and Grindrod 2006) or geysers (Lorenz 2002). Artemeva (2003) suggest water

7. 4
may be present from comet/asteroid impacts. Sarker et al. (2003) pointed out that “aqueous
cryovolcanic flows may remain partially molten for very long periods if they contain significant ammonia.
These flows may induce hydrolysis of tholins to produce amino acids, the building blocks of RNA and
DNA (Neish et al. 2007, 2008, 2010)
Atmospheric
According to the literature review by Norman and Fortes (2011), methane based life would “produce
anomalous depletions of hydrogen, acetylene and ethane, as they consumed these substances”. There
are many open questions relating to this proposal. Based on Cassini data, Lorenz et al. (2008) points to an
unexpected lack of ethane on the surface. Strobel (2010) found that the Cassini data suggests a lack of
hydrogen. According to an article by Cowen (2010), “Darrell Strobel of Johns Hopkins University in
Baltimore found that 10,000 trillion trillion hydrogen molecules fall out of the atmosphere per second. But no
corresponding build-up was seen at the surface.” Clark et al. (2010) describe an unexpected depletion of
acetylene at the surface given expected rates of atmospheric production and subsequent deposition on the
surface. Furthermore the Huygens probe did not detect acetylene on the surface. Huygens did not have
equipment to test for bio-signatures.
Figure 4: The first images from the Huygens probe during descent

8. 5
3. Mission Statement
3.1. Mission Statement
Based on the existing information known about Titan and the tantalising questions that remained
unanswered, the mission statement of the Titan Boat Project is:
Interplanetary study of Titan‟s polar sea, Ligeia Mare by autonomous boat for 100 days in
order to enhance humanity‟s understanding of life in the solar system.
3.2. Mission Objectives
The Titan Boat’s science objectives seek to answer two broad questions: can Titan support life? And what
is the lake topography? Science objectives were designed to help answer these questions as shown in
Table 1. The payload systems are explained in more detail in section 9.3. Each payload package contains
a multitude of sensors. The underneath package describes the sensor kit that is mounted on the base of
the Titan Boat for below surface remote sensing.
Table 1: Science objectives and the payloads used to investigate
Objective A: Can Titan support life? Payload systems used to investigate objectives
A.1. Lake environment
What are the chemicals in the lake? Spectrometer package
What is the temperature? Underneath package
What is the density? Spectrometer package
A.2. Atmospheric environment
What is the chemical composition? Spectrometer package, gas collector and dissociator
What is the radiation? Environmental Package
What is the weather system like? Environmental Package
Objective B: What is the lake topography?
How deep is Ligeia Mare? Underneath package
What is the composition of the lake bed? Underneath package
What does the lake look like? Camera system

9. 6
4. Stakeholders
Customers
This report defines customers as the intuitions paying for the Titan Boat Mission. The Titan Boat mission
will be a worldwide collaborative program including National Aeronautics and Space Administration
(NASA), the European Space Agency (ESA), as well as several separate American and European
academics and contractors. The international composition of Titan Boat team guarantees that the mission
responsibility and expenditure would not be borne by any single organisation. Through sharing investment
and participation, the risk and cost will be largely alleviated.
End customers
The international science team investigating Titan will comprise some 250 experts from 15 countries and
regions. Their research will be made publically available such that the end customer is ultimately the
international general public.
Operations
In America, this mission will be supervised under NASA and led by the Jet Propulsion Laboratory (JPL).
JPL will provide project management, systems engineering, mission assurance, payload, SEP, navigation,
mission operations and data management. At JPL, Robert T. Mitchell will be proposed to be the Titan Boat
program senior supervisor. Dr Linda J. Spilker will be the Titan Boat mission scientist and Dr Amanda R
Hendrix will be the mission deputy scientist. At NASA, Bill Knopf will be Titan Boat program management
director and Curt Niebur will be Titan Boat program chief scientist.
Prime Contractor
Lockheed Martin is the prime contractor in America who will construct the Titan Boat and Titan Boat
propulsion units and the electricity generators. In Europe, the Titan Boat will be supervised by the
European Space Technology and Research Centre. Alcatel will be responsible for assembling the Titan
Boat with equipment furnished by many European contractors. At ESA, Dr. Jean-Pierre Lebreton will be the
Titan Boat chief manager and chief project scientist.
Other mission stakeholders
Table 2: Other mission stakeholders
Stakeholders Function
UCLA (University of California, Los Angeles)
Science lead, science operations, data products,
archiving, and analysis
KSC (Kennedy Space Centre) Responsible for launch operations
DSN (Deep Space Network) Responsible for data return from spacecraft

10. 7
5. Timeline
The mission timeline is divided into the major mission components (Osborne 2015). Phase A and B take
approximately one year while Phase C/D will take around three years (the minimum time for space
mission1
) for the completion of detailed design and manufacturing. The Phase E operations schedule is
based on the Cassini-Huygens Mission (Munsell, n.d.) and comprises almost seven years of interplanetary
travel to Saturn, followed by three months of orbit preparation around Titan. Once the Titan Boat probe
detaches from the orbiter it will spend roughly twenty days from release to travelling toward Titan before
entering its atmosphere. Landing will take up to three hours after which mission operations will be
conducted for 100 days. After the 100 days the Titan boat is parked at a suitable area on the lake and the
mission will cease.
Figure 5: Mission timeline diagram
Table 3: Mission timeline description
1
According to The Lunar and Planetary Institute (2012), 2016 is the most efficient launch window with last chance for a low cost mission in 2023. Due to this
programmatic constraint Phase C/D was minimised to 3 years since phases A,B are as short as they can be and phase E is beyond control.
Phase C/D
Phase E
2027 2028
Phase A
Phase B
2021 2022 2023 2024 2025 20262015 2016 2017 2018 2019 2020
Phase F
Start date Phase Function
2015 April A Feasibility phase: define system concept and assess various functional concepts
2015 October B
Preliminary definition: define system and sub-system designs in detail to progress to
phase C
2018 April C/D
Complete designs and analysis, prepare drawings and procedures, complete
development and qualification testing, manufacture of hardware and acceptance testing
2020 October E Launch
2021 April E First Venus flyby
2021 June E Second Venus flyby
2021 August E First Earth flyby
2024 December E Jupiter fly by
2027 June E Arrive Saturn
2027 October E First Titan orbit
2027 December E Titan Boat probe release
2028 January E Titan Boat probe enters Titan atmosphere
2028 April F End of mission

11. 8
6. System Concept
The Titan Boat mission will land a boat probe on Titan’s lake, Ligeia Mare. It will float on the lake’s surface
and propel itself to navigate and conduct its science mission for 100 days. Longer mission duration allows
for the return of valuable scientific data and for the observation of Titan’s dynamic weather system. More
detailed discussion of the features on the Titan Boat can be found in the following section
Figure 6: Titan boat concept
Figure 7: Titan Boat profile views

12. 9
7. Concept of Operations
Landing Operations
When the Titan Boat and its Orbiter arrive at Titan it puts itself into the correct trajectory for Ligeia Mare.
The Titan Boat Probe is ejected from the orbiter using explosive bolts on its trajectory to Ligeia Mare before
the Orbiter boosts itself out of the same trajectory into orbit around Titan.
The Titan Boat will enter Titan's atmosphere at a velocity of 6.1 km per second. The entry phase will last
about 3 minutes, during which the probe's velocity will decrease to about 400 meters per second as it is
converts its kinetic energy into heat as it soars through the Titan atmosphere (Clausen et al. 1999).
Three parachutes will be used during the probe's descent. When the on-board accelerometers detect a
speed of Mach 1.5 near the end of the deceleration phase, a 2-meter-diameter pilot parachute will deploy,
pulling off the aft cover. This will follow immediately by deployment of the 8.3-meter main parachutes. The
parachutes are made of Kevlar and nylon fabric (Clausen et al. 1999). About 30 seconds after deployment
of the main chute, the Titan Boat will slow from Mach 1.5 to 0.6.
Following this, the front heat shield will then be released and the Titan boat will descend slowly for 15
minutes. The main parachute will then separate. Another smaller 3- meter drogue parachute is deployed
until it hits the surface of Ligeia Mare with an impact velocity of about 7 meters per second (ESA 2015 and
Clausen et al. 1999).
Figure 8: Landing operations for the Huygens probe which the Titan Boat will largely mirror
Mission operations
After landing on Ligeia Mare, the Titan Boat will start its 100 days science mission. This mission has two
goals, exploring for evidence of whether life could exist on Titan and the topography of Titan Sea as
described in section 3.2. In order to fulfil the first goal, the Titan Boat will need to survey various areas
around Ligeia Mare. There are three objectives during the lake survey part. Firstly, Titan Boat needs to
cruise around Ligeia Mare to determine the chemical composition, through deploying spectrometers.
Secondly, Titan Boat should using thermal scanner to determine the temperature change and distribution of

13. 10
Ligeia Mare and the Titan atmosphere. After that, Titan Boat will deploy fluid density instruments to
research the density of Ligeia Mare.
For the atmospheric science objectives, Titan Boat will use its environmental instruments pack to determine
the weather system and near surface radiation of Ligeia Mare. The Titan Boat will deploy its gas collector
and dissociator to dissolve and separate gas samples for the spectrometer instruments pack to analyse.
To investigate the lake topology, the Titan Boat will use its underneath instruments package to measure its
depth and composition. The acoustic scanner will uncover the depth and topography of Ligeia Mare. Its
camera system will create the panoramic images of Ligeia Mare’s surface during its science operations.
Figure 9: Map of Ligeia Mare on which science operations will be conducted

14. 11
8. Requirements
The system functional requirements are captured in Figure 10. These function actions must be performed
in order to achieve mission success.
Figure 10: Function tree for the Titan Boat Project
Table 5 expresses the information in the above function tree into table form. It is used to complement the
function tree and represent the relationship between higher and lower functions.
Operational Requirements, Limits and Constraints
In addition to the functional requirements, every space mission is also subject to operational requirements
and limits and constraints. Operational constraints describe how the system is used including interaction

15. 12
with system operators and users while constraints and limits are those imposed beyond the control of the
mission designers such as budgets, schedule and implementation techniques, operating environments etc.
Table 4: Operational Requirements and Limits/Constraints
O1.Mission duration: 100 days on the surface of Ligeia Mare
O2.Reliability
a. Design robustness: High priority given to robustness to the
detriment of mass, power and data returned. Critical functions
shall have triple redundancy including probe-wake up function and
measurement of deceleration profile
b. Failure tolerance
c. Redundancy (duplicate / backup / temporal)
i. Electrical sub-system shall have two duplicate parallel units
ii. Command and Data Handling System shall have two
duplicate parallel units, fully physically separated. Shall
have a flexible system in which its software can be updated
remotely. Mission Timer Unit to be triple duplicate
redundant. Central Acceleration Sensor Unit to be
supported by backup system
iii. Communications sub-system shall have two duplicate
redundant system
iv. Pyrotechnic devices shall have a duplicate parallel units
O3.Data distribution: From JPL operations team to broader NASA/ESA
O4.Science mission: Payloads need to be mounted to maximise achievability
of science mission
L1. Programmatic constraints: 2016 launch window more most efficient
trajectory (7.5 year cruise) with a last chance for low cost mission in 2023-
24 (Lunar and Planetary Institute 2012). October 2020 is selected for the
mission launch.
L2. Environmental
a. Launch
I. Mechanical: up to 3g acceleration during launch
b. Space
I. Radiation: Ensure electronics hardened to withstand
particle radiation from the sun and from outside the solar
system (NASA 2015)
II. Thermal: Survive temperatures as cold as 2.7 kelvin (BBC
2013)
III. Communications with Earth from Titan will have a one hour
Operational
Requirements
Limits and
Constraints

16. 13
lag (Lebreton et al. n.d.)
c. Titan
I. Mechanical: Up to 12g of deceleration during re-entry.
Parachutes must operate in supersonic conditions of Mach
1.5. Up to 5m/s (18km/h) splash down speed (Lebreton et
al. nd).
II. Thermal conditions during entry and descent: Survive both
atmospheric entry heat and descent convective cooling
conditions. Actual temperatures unknown since Huygens
heat shields did not have sensors but it was designed to
survive max heat flux of 1400kW/m2
for the front shield and
30-120kW/m2
for the rear (Bouilly 2005)
III. Surface conditions: Pressure 1.5bar, methane and
Nitrogen environment. Surface temperature of minus 180
degrees Celsius. Thick atmosphere rules out solar power
systems (Lebraton et al. nd). Methane is explosive.
IV. Ligeia Mare: located at 78°N, 250°W, expect hydrocarbon
precipitation near poles (Stofan et al. 2010), possibly has
methane ice on the lake surface, waves about 2cm high,
and wind speed of 0.75m/s (BBC 2014)
L3. Interfaces: subsystems and payload mass shall be evenly distributed
around the centre axis of the Titan probe. Furthermore, the heaviest
components should be mounted as low as possible to improve stability on
Ligeia Mare
L4. Launch vehicle payload limits: 4850 kg (orbiter plus Titan Boat) due to
SpaceX Falcon 9 launch vehicle limits to Transfer Orbit.
L5. Cost: $3bn (replicate Cassini/Huygens cost)
Functional Block Diagrams
A functional block diagram emphasise the interfaces and interrelationships between functional entities
(inflows and outflows). It is based on the system requirements already defined in Figure 10. The following
figures describe the key functional interrelationships of the Titan boat mission: landing on Ligeia Mare
(Figure 11) and conducting the science mission operations (Figure 12). Landing operations have three
concurrent functions identifying and tracking Ligeia Mare’s location, maintaining the correct trajectory and
surviving the conditions during atmospheric entry. These are all important functions while entering Titan’s
atmosphere. Science operations are much more sequential. Monitoring the health of the Titan Boat via
telemetry, however, is a parallel function on top of the science operations.

17. 14
Figure 11: Function block diagram for landing on Titan
Figure 12: Function block diagram for mission operations
Functional Matrices
Functional matrices are used to describe any interrelationships within functional requirements (Osborne
2015), hardware systems or any other area of concern during system design. Table 5 maps lower level

18. 15
functional requirements with higher level requirement while Figure 13 maps requirements to hardware
systems for the individual Titan Boat teams to design their respective subsystems.
Table 5: Function Matrix for the Titan Boat Project mapping level 2 functions
Figure 13: Functional matrix: Requirements vs. subsystem as used for subsystem design
F1.1. F2.1. F.2.2 F2.3 F3.1. F3.2. F3.3. F3.4. F3.5 F3.6. F3.7. F.4.1. F4.2. F4.3. F4.4. F4.5. F4.6. F4.7. F5.1. F6.1.
F1.0 x
F2.0 x x x
F3.0 x x x x x x x
F4.0 x x x x x x x
F5.0 x
F6.0 x
Level 2 Functions
Level 1 Functions
A
D
C
S
Pow
er
C
D
H
S
C
om
m
s
Propulsion
Therm
al
B
oatstructure
Payload
Therm
al
Structure
ParachuteG
round
A
rchitecture
Jason Felix Jason Hassan Meiyappen Meiyappen Jason Felix Meiyappen Meiyappen Meiyappen
F1. Leave Earth
a. Launch satellite into space
F2. Get to Titan
2.1. Enter into the correct trajectory for Titan
2.2. Thrust to Titan
2.3. Orbit Titan
F3. Land on Ligeia Mare
3.1. Detach from the Orbiter X
3.2. Identify Ligeia Mare's location X
3.3. Maintain and enter into the correct trajectory to land on Ligeia Mare X X X
3.4. Survive atmospheric entry X X X X X X
3.5. Splash down on Ligeia Mare X
3.6. Float on Ligeia Mare X
3.7. Establish and maintain communications with Earth X
F4. Perform Mission Operations
4.1. Identify current location on Leiga Mare X X X
4.2 Transmit location to Earth X
4.3. Receive new target location and science plan X X
4.4. Navigate to new location on Leiga Mare X X X
4.5. Activate and operate payload systems according to science plan X
4.6. Store science mission data X
4.7. Monitor health of Titan Boat X
F5. Transmit Results X
F6. End of Mission X X X
O1. Mission duration: 100 days X X X X X X X X
O2. Reliability
a. Design robustness: High priority given to robustness to the detriment of mass,
power and data returned
b. Fault tolerance X X X
c. Redundancy (duplicate / backup / temporal)
i. Electrical sub-system shall have two duplicate parallel units X
ii. Command and Data Handling System shall have two duplicate parallel
units, fully physically separated. Shall have a flexible system in which its software can be
updated remotely
X
iii. Communications sub-system shall have two duplicate redundant
systems
X
iv. Pyrotechnic devices shall have a duplicate parallel units X X
O3. Data distribution: From JPL operations team to broader NASA/ESA X X
O4. Science mission: Payloads need to be mounted to maximise achievability of science
objectives
X
L1. Programmatic constraints: 2016 launch window more most efficient trajectory (7.5 year
cruise) with a last chance for low cost mission in 2023-24 (Lunar and Planetary Institute 2012)
L2. Environmental X X X X X X X X
a. Launch
I. Mechanical: up to 3g acceleration during launch X X X X X X X X X X X
b. Space
I. Radiation: Ensure electronics hardened to withstand particle radiation
from the sun and from outside the solar system (NASA 2015)
X X X X X X X X X X X
II. Thermal: Survive temperatures as cold as 2.7 kelvin (BBC 2013) X X
III. Communications with Earth will have a 1 hour lag X X
c. Titan
I. Mechanical: Up to 12g of deceleration during re-entry. Parachutes must
operate in supersonic conditions of Mach 1.5. Up to 5m/s (18km/h) splash down speed
(Lebraton et al. nd).
X X X X X X X X X X X
II. Thermal conditions during entry and descent: Survive both atmospheric
entry heat and descent convective cooling conditions
X X
III. Surface conditions: Pressure 1.5bar, methane and Nitrogen
environment. Surface temperature of minus 180 degrees Celsius. Thick atmosphere rules
out solar power systems (Lebraton et al. nd). Methane is explosive.
X X X X
IV. Ligeia Mare: located at 78°N, 250°W, expect hydrocarbon precipitation
near poles (Stofan et al. 2010), possibly has methane ice on the lake surface, waves
about 2cm high, and wind speed of 0.75m/s (BBC 2014)
X X X X
L3. Interfaces X X X X X X X X X X X
L4. Launch vehicle payload limits
L5. Cost: $3bn (replicate Cassini/Huygens cost)
Functional
Requirements
Operational
Requirements
Limits and
Constraints
Titan Boat
Atmospheric Entry System
Ground Architecture

19. 16
9. System Architecture
9.1. Launch Vehicle
The launch vehicle will be SpaceX’s Falcon 9. This vehicle was selected because it is currently delivering
commercial spacecraft services and represents another opportunity to grow the private space sector. It can
launch a 4.8 tonne geosynchronous transfer orbit and costs USD61 million degrees (SpaceX 2015). A
geosynchronous transfer will be useful for maximising apogee for the orbiter craft (on which the Titan boat
will be piggy-backing) to break out of earth orbit.
9.2. Orbits and Trajectories
The Titan Boat mission will use the same orbit and trajectory design as the Cassini/Huygens mission which
successful delivered the spacecraft onto Titan’s surface. The flight time to Saturn is around seven years
and requires gravity assists from Venus, Earth and Jupiter (Labreton et al. 2002) as described in Figure 14.
Unlike the Cassini/Huygens mission, however, the Titan Boat mission will not include a targeted flyby of the
moon Phoebe.
Figure 14: Trajectory to Saturn (Labreton et al. 2002. Edited to remove dates)
Upon reaching Saturn orbiter/probe will enter a highly eccentric capture orbit as described in Figure 15. The
first two orbits are used to prepare for the required geometry that needs to be achieved for the Huygens
mission on the third orbit where the orbiter and the Titan Boat probe are targeted for a collision path to
Titan. 22 days before a collision, the Titan Boat probe separates. The orbiter will then manoeuvre to avoid
Titan and place itself in orbit around Titan. Like Huygens, the Titan Boat Probe will coast for 22 days with
no possibility of changing the attitude parameters acquired at separation (Clausen, KC et al. 1999). Given

20. 17
this operational constraint it is critical that the orbiter/Titan Boat probe is placed in the correct trajectory to
Ligeia Mare.
Figure 15: Orbit around Titan (Labreton et al. 2002. Edited to remove dates)
9.3. Payloads
The payload systems are the critical for performing the science mission and completing the objectives
described in section 3. The payload drives the design of the subsystems since they support the operation of
the payloads. The payload used on the Titan Boat largely comes from the Mars Curiosity Rover due to it
being the relatively new technology with solid space heritage. A summary of the payload systems used in
on the Titan Boat is shown in Table 6. More detailed descriptions of the payload systems is discussed in
the following sections.
Table 6: Summary of payloads used on the Titan Boat
Main Cameras (MAC)
The Main Camera, or MAC for short, can take colour pictures of Titan’s surface. These pictures can be
used to produce a set of panoramas Titan by stitching them together. Similar to the cameras on the Mars
Exploration Rovers Curiosity, the MAC is comprises two coaxial camera systems mounted on the top of the
Titan Boat. The MAC is designed to study the Titan landscape, observe frost and weather conditions and
also to support the cruise and sampling actions of the Titan Boat (Mast Cameras n.d.).
Payload Function Power (W)
Camera systems Photography and navigation 13 based on Mars curiosity
Spectrometers Examine elemental composition 42 based on Mars curiosity
Gas collector and dissociator
Breaks gases down for the
spectrometers
28 based on Huygens probe
Environmental sensors Measure weather conditions 10 based on Mars Curiosity
Underneath package Measure lake bottom topography 10 based on Huygens probe
Total Payload Power 100

21. 18
Figure 16: Example of a twin camera system on the Mars Curiosity Rover
Spectrometers
Spectrometers can examine the composition elements of compounds. These elements that this mission
mainly focus on, concluding carbon, hydrogen, and oxygen, methane, since they are associated with life
that existing on earth. Because compounds are the key factors to form life on existing knowledge, their
kinds and amounts will contribute to a vital section of evidence for assessing life form of Titan and the
evolution procedure of life on it. There are three instruments in spectrometers package, including a mass
spectrometer, gas chromatograph, and rotatable laser spectrometer. Sample analysis on Titan will also
search and measure the existence of other assumption light elements, such as phosphorus, sulphur and
silicon.
The mass spectrometer is designed to identify components by mass for analysis and measurement.
The gas chromatograph is designed to identify gases components by heating samples, these gases source
form vaporized samples in different temperatures. The laser spectrometer is designed to identify a variety
of isotopes of carbon, hydrogen and oxygen in near-surface atmosphere, including methane, water,
ammonium and other likely element (Mahaffy 2013).
Figure 17: Sample Analysis payload for the Mars Curiosity mission
Gas collector and dissociator (GCD)
The gas collector and dissociator is used to collect and heat sample from liquid and atmosphere and then
transfer them to the Gas Chromatograph (Lebreton & Matson 2002, p.59 ).

22. 19
Figure 18: Gas collector payload used on the Huygens probe
Environmental Sensors (ES)
The environmental sensors pack is designed to observer the weather, near-surface and atmosphere
temperature and also pressure (Rover Environmental Monitoring Station n.d.). Through these
measurements, Titan Boat could collect detail data about everyday pressure and temperature, humidity,
space particle radiation at the Titan surface, atmosphere wind speed and direction (Armiens et.al 2012,
p.583).
Figure 19: How environmental sensors can be mounted on the mast
Underneath Package (UP)
The underneath pack consists of five separate working units, including lean sensor, thermal scanner,
acoustic scanner, permittivity detector and density detector. They are used to research the topography,
temperature distribution and range and also possible floating materials in the Titan sea (Lebreton & Matson
2002, p.59 ). The lean sensor consists of a gravity sensor, Doppler lidar and a set of gyroscopes. It could
measure the sea current and sea wave variation trend. The thermal scanner unit consist of infrared heat
radiation imageries which can detect sea temperature at different layer and areas. The acoustic scanner
unit consist of two ultrasonic sound detector and one laser distance detector. They are used to detect
seabed structure and possible suspended materials. Also, these detection data could be used to depict
topography on Titan. The permittivity detector unit contains two electrodes. Through detect material fluid
between two electrodes, liquid permittivity can be found. In addition, this unit could be used to detect any
possible polar molecules in Titan Ocean. The density detect unit consists a set of Archimedes buoyancy
sensors around Titan Boat. It also contains four gasbags which could to help instrument floating on the
surface of Titan Sea through filling gas in Titan surface.
Payload layout on the structure
Figure 19 displays the layout of the payloads on the Titan Boat structure. It is only conceptual for the
moment and would require more detailed evaluations for further optimise the layout. The Titan Boat needs
to be stable on the surface of Ligeia Mare. This means that the heaviest items need to be monuted lower

23. 20
than lighter items to lower the overall centre of mass. Another balance requirement is that the payload and
subsystems need to be distributed evenly around the centreline of the Titan Boat’s circular structure.
Figure 20: Mounting locations for payload systems on the Titan Boat (based on Huygens configuration)

24. 21
9.4. Subsystems
Design Summary
Figure 21 demonstrates a very high level block diagram of the major subsystems on the Titan Boat Mission
and their interrelationships based on power and data distribution. It highlights the major components of the
individual subsystems.
Figure 21: Subsystem block diagram
Figure 22 documents the design interfaces between subsystems and the payloads via an N squared
diagram. During the conceptual design phase where the Titan Boat project team designed the subsystems
according to the functional matrix diagram in Figure 13 , it was found that changing one subsystem design
would have knock-on effects on other subsystems. The N squared diagram captures these inter-
relationships so that the team is aware of the impact of their design updates.
Figure 22: Titan Boat Subsystem interface N2 diagram
9.4.1. Command and Data Handling Subsystem (CDHS)
The CDHS for the Titan Boat will have the same functional requirements as Huygens, that is, autonomous
control of the probe after separation from the orbiter. The CDHS will execute ‘Pre-programmed sequence
triggers parachute deployment and the heat-shield ejection’ (Clausen et al. 1999). Given the success of the
Huygens architecture and design heritage, it will be implemented for this mission.
As described by Couzin (2005) and Clausen et al. (1999), the major components of the CDHS are:
Payload Data handling rate Power required by payloads Minimum operating temperature for payload Data transfer rate required Payload mounting locations
Sends commands to payload CDHS
Send commands to power system
Power required by CDHS
Minimum operating temperature for CDHS
Sends commands to thermal system
Send commands to propulsion system
Send commands to communications
system
Mounting location
Power Minimum operating temperatures for battery Mounting location
ADCS Mounting location
Power required by thermal system Thermal Mounting location
Power required by propulsion
Battery design Propulsion Mounting location
Receive software upgrades
Power required by communications
system
Minimum operating temperature for communications
system Communication Mounting location
Available volume Available volume Available volume Available volume Available volume Available volume Available volume Structure

25. 22
 2 x Command and data handling unit (CDMU) system. This system controls the probe operations.
Each will operate its own software independently in parallel and are fully physically separated. It
was designed such that no failure of one chain would impact the other chain. This allowed major
simplification and increased robustness. It is a fully flexible system that had the capability to have
large portions of its software updated.
 3 x Mission Timer Units (MTUs). This is used to activate probe after end of coast phase after
separating from the orbiter.
 2 x mechanical g-switches (MTU backup). These ensure the Titan Boat will wake up in the event of
atmospheric entry without time-out signal from any timer boards. They are purely mechanical
devices that work when deceleration reaches 5.5-6.5 g (Clausen et al. 1999).
 3 x Central acceleration sensor unit (CASU): These measure the axial deceleration to calculate the
time at which the parachute will deploy. Three devices mitigate failure and reduce uncertainties from
single measurements.
 2 x Radio Altimeter Units (RAU). These provide the altitude data at heights lower than 25km
(Clausen et al. 1999) for each of the two CDMUs.
The CDHS will run software to meet three operational requirements including: mission management,
telemetry management, and telecommand management (Clausen et al. 1999). For mission management,
the software will take sensor readings from the accelerometers, altimeters, and mission timer units to
determine when to deploy the parachutes. It will also forward commands to the subsystems and payload
equipment according when it receives instructions from the operations team on Earth. It will also continually
assess the state and health of the Titan boat from the sensor readings. For telemetry management, the
software will collect and store data and transmit to the communications system to deliver back to Earth. For
Telecommand management, the software allows for receiving instructions when the Titan Boat is still in
transit to Titan for any software updates and to forward commands to the payload and subsystem if
required.
9.4.2. Structural Subsystem
The structure provides mounting support for the payload and subsystems and protects these systems from
the harsh environment of Titan’s lakes. The mounting platforms need to be strong yet lightweight. Using
Huygen’s materials heritage, the Titan Boat mounting structure will also be constructed from aluminium
honeycomb sandwich platforms to meet these requirements. (Clausen et al.1999). There will be two
mounting platforms. The top level is for the communications subsystems while the lower level is for the
payload and all other subsystems.
The overall casing will comprise and after cone and fore-dome made from aluminium shells. Aluminium can
withstand liquid methane and has a successful history for storing liquefied natural gas storage on earth:
„[Aluminium‟s excellent mechanical properties at cryogenic and ambient temperatures, combined with
superior corrosion resistance, make it attractive for applications such as LNG tankers or storage tanks‟
(Alcoa, 2015). The aluminium casing is also hardened to withstand any collisions with hydrocarbon ice on
Ligeia Mare whether that be during landing (base impact) or mission operations (side impacts). The casing
is fully sealed except for a vent hole on top to handle depressurisation and pressurisation when it goes
through environments (earth, space, Titan). The after cone and fore dome and mated by a central ring. The
exterior of the structure will have spin vanes to provide spin control during descent.

26. 23
Figure 23: The Huygens probe outer structure from which the Titan boat will draw heavilty upon
9.4.3. Attitude Determination and Control Subsystem (ADCS)
Attitude determination in the case of the Titan Boat requires measuring the orientation of the boat on the
surface of Ligeia Mare. This is critical for the science operations since the boat will need to rotate itself and
for health monitoring and telemetry. Attitude determination will come from three redundant gyroscopes and
three redundant accelerometers (3-axis) that serve as backup systems. When combined they will feed
multiple measurements equivalent of aircraft pitch, yaw and roll that will be used to navigate the Titan Boat.
Roll control is achieved through passive structural design. The driving reason for this design decision is that
it is expected that the liquid conditions on Ligeia Mare is calm (2cm waves, wind speed 0.75m/s, BBC
2014). Thus active control systems were not considered since they would add unnecessary complexity and
weight. The fore-dome structure will be designed to passively balance and return to an upright position
(positive stability) on the lake’s surface. This is achieved by ensuring the centre of gravity of the Titan Boat
is kept as low as possible by mounting the heaviest items around the toward the bottom of the Titan Boat
and evenly around it’s centre line (Maritime New Zealand 2011). The fore-dome base will have a wide
surface area and a flat hull design given calm liquid conditions on Ligeia Mare. Flat hull designs are good
for slow speeds and calm condition (Hull types 2015). Liquid methane ingress is prevented by sealing the
case.
Yaw and pitch control is achieved by the propulsion system described in section 9.4.7.
9.4.4. Power Subsystem
Power generation system
The Titan Boat will be powered by 8 multi-mission radioisotope thermoelectric generators (MMRTGs),
fuelled by 40kg of plutonium 238, to support a maximum total power requirement of roughly 1000W. Each
MMRTG weights 45kg. The MMRTG unit has space heritage on the Mars curiosity rover, which itself is
powered by three MMRTG units.
The two main components of a nuclear thermoelectric generator is a heat source containing the radioactive
material and a set of solid-thermo couples that convert heat into electrical energy (Jiang 2014). Plutonium
238 was chosen for its ability to emit high energy radiation. The power system uses non-weapons grade of
radio isotope. The thermo couples convert heat energy into electricity by relying on the „seebeck effect‟,
where differential temperatures creates electric voltage (JPL 2013). To prevent contamination of radioactive
material in the worst case of leaks the plutonium is stored in high strength blocks of graphite surrounded by
a layer of iridium metal.
Estimating total Power Required
To estimate the total power required for the Titan Boat, the AIAA estimation method was used based on the
known payload power requirements (100W). The total power requirements are estimated using the AIAA
„Total spacecraft power estimating relationship‟ formula based on a planetary mission. Then using the

27. 24
margin estimate guide from AIAA recommended power contingencies, a figure of 80% was selected based
on a Class 1 (New Bid) category BP (500-150W) design.
Figure 24: MMRTG unit used on Mars Curiosity Rover
Table 7: Power budget estimate
Justifying the selection MMRTGs
Given the high amount of power required of 1000W and the mission duration of roughly 3 months, only a
nuclear energy source can provide the required amount of power per Figure 25 (Tsafnat 2015).
Furthermore, a nuclear power system is advantageous on Titan since Titan’s atmosphere would be too
thick for any reliable use of solar panels (Clausen et al. 1999). Approximately 40kg of plutonium is required
to power 8 MMRTGs (see Table 8).
Figure 25: Space mission power sources from AERO9500 lecture slides, week 3
Power estimation Method
Total power required (excl.
propulsion)
( )
From AIAA Total spacecraft power estimating relationship for planetary missions
Total power required incl.
margin (excl. propulsion) From AIAA recommended power contingencies for Class 1, Category BP
Total power required incl.
power and propulsion
880W + 100W = 980W ~ 1000W
From adding 2x 50W electric propulsion systems

28. 25
Table 8: Plutonium mass estimate
Power storage
The Titan Boat mission will use the same battery technology from the Huygens probe. The Titan boat will
have 14kg of lithium sulphur dioxide batteries with enough capacity to supply 210W of power. This
technology was selected because the Huygens batteries were specifically designed to handle the extremely
cold temperatures of Titan. Commercial lithium ion batteries degrade in performance as temperatures
decrease below zero. According to Buchmann (2015), these batteries stop functioning at -20 degrees
Celsius. The Huygens batteries, however, had a minimum operating temperature of -40 degrees Celsius.
These batteries will still need a external heating from the Thermal subsystem.
The batteries uses lithium metal foil as the anode and sulphur dioxide as the cathode reactant or
depolarizer. The cathode itself is a Teflon-bonded porous carbon matrix pressed into a metallic screen.
These batteries are highly energy density and highly voltage, and are potentially long shelf life (Halpert and
Anderson 1982).
The batteries will have sufficient capacity to service 210W of power demand. 100W is dedicated to the
propulsion system while the remainder serves as a backup for critical subsystems like communications. A
1kg lithium sulphur dioxide battery supplies 15W. So to supply 210W, 14kg of batteries is required. In the
event of fire, a graphite-type compound or extinguisher such as Lith-X-type (class D) will extinguish burning
lithium (Halpert and Anderson 1982).
9.4.5. Thermal Subsystem
The purpose of a thermal subsystem is protect the payload and subsystems in the spacecraft by keeping
their temperatures within limits. This is critical because electronics can only operate within a temperature
range, beyond which they either stop operating or worse, sustain physical damage. There are two types of
Thermal Subsystem that will be used on the Titan Boat. Active thermal control, although expensive, allows
for direct control of temperature by use of powered electric heaters and coolers. Both will be employed on
the Titan Boat to maintain minimum temperatures during science operations and for emergency cool down
during landing operations. The other is passive thermal control, which is less complex and relies on heat
pipes, coatings and insulation for example. This is employed on the Titan Boat as well as the heat shields
during atmospheric entry into Titan. The thermal system will draw extensively from the heritage from the
Huygens space probe.
Front heat shield
The purpose of the front shield is to decelerate the probe in the upper atmosphere of titan to reduce entry
speed from 6km/s to 400m/s (Mach 1.5) at altitude of 150-180km as well as protect the Titan Boat from
extreme heat (Clausen et al. 1999). During this period the Titan Boat will create a plasmas shock wave of
around 12,000 degrees Celsius (Piazza, n.d.). To survive these extreme conditions, the shield is made
Carbon fibre reinforced plastic honeycomb shell and ablative AQ60 heat tiles on its exterior to resist a heat
flux of 1.4MW per metre squared (Clausen et al. 1999).
Power generated (W) Estimated mass of plutonium required
870 4.8kg (Capotini 2008)
Based on the Mars Curiosity rover which uses 1 x MMRTG offering 120W
1160
40.0kg
Assuming the above relationship is linear and estimating number of MMRTGs needed to meet 1000W
requirement

29. 26
Figure 26: The Huygens front shield design which the Titan Boat will reuse
Back shield cover
The back cover provides insulation protect the Titan Boat during cruise and coast phase of landing
operations on Titan. During launch a hole assure depressurization and repressurisation during entry. It is
made of aluminium shell, which is stiffened just like on the Huygens probe (Causen et al. 1999). It has
access door for integration and emergency cool down of the probe and a breakout patch for firing the first
parachute.
Titan Boat thermal system
To survive the cold conditions of -180 degree Celsius on Ligeia Mare, the Titan boat will combine active
and passive thermal technologies. It will have multi-layer insulation and heat pipes that conduct heat from
the thermoelectric power generator to distribute heat to the temperature-sensitive critical componentry. It
will also have electric coolers and heaters around vital subsystem components which activate when
temperatures are measured to be too cold or hot.
9.4.6. Communications Subsystem
The Titan Boat mission will use the orbiter relay communication system like the Cassini-Huygens mission. It
comprises two redundant parallel communications systems. It has two s-band channels for each of the
CMDU’s consisting of a dedicated transmitter unit, 10W RF solid state power amplifiers (Couzin et al.
2005). The communications system also had two low noise amplifiers (Clausen et al. 2002). The orbiter will
have two high gain antennas pointed in the direction of the Titan Boat probe to receive its signals and relay
to Earth (Couzin et al. 2005).
A huge constraint on the communications systems on Huygens was its limited power. According to Couzin
et al. (2005), Huygen’s uplink rate could be boosted up to 2.6 times if it reduced its mission life time from 3
hours to 30minutes. Since the Titan Boat has significantly more power available to it, the Titan Boat mission
will be able to send unprecedented amount of data back to Earth. A problem encountered during the
Huygens mission was Doppler shift during entry into Titan’s atmosphere. This will be corrected from the
body of knowledge about this problem for the Titan Boat mission.

30. 27
9.4.7. Propulsion Subsystem
The Titan Boat mission duration is 100 days. In order to maximise the science value during these 100 days
it was required for the Titan Boat to be able to navigate on the surface of the Ligeia mare. The propulsion
system on the Titan Boat comprises 2 x 50W electric motors.
Figure 27: Example of electric boat propulsion unit from Volt master
Electric propulsion motor will be suitable choice for this operation because of its efficiency and light
compact structure. They can provide powerful torque and full power instantly with no need of warming up. It
has a smooth operation on very low speed with high level of reliability (Whisper Power, n.d.). The general
configuration of electric propulsion motor is generator, electric motor and static converter. To be clear
usually we use a diesel generator in boats, which is going to be replaced by MMTRG here that is, going to
generate electrical energy and to store the energy we need a Li/S02 cell, which is 14 in number each, can
store 15W(Explained briefly in batteries). Combined propulsion is in which the motor is supplied by a
separate source power being added to the direct propulsion. Electric motor gives power to the propelling
shaft.
The simple calculation based on resource and assumption since this concept has not yet be tested before.
 Generally, a 1kW power motor can make a boat to travel 10km/hr, which is 3m/s. (Eco boats, n.d.)
 Liquid Methane is only 45% as dense as water. It means it is less viscous than water. (PHYS.ORG,
April 2014), which can be approximated as 50%. If we take the above condition and assume that
density is proportional to boat speed, then Titan Boat can travel 20km/hr in liquid methane.
 It is a design decision to significantly reduce the speed of the boat since speed is not a mission
critical. The maximum speed will be fixed to 1km/hr, which is 0.3m/s.
 Assuming the the 1kW to 10km/hr relationship is linear, then for 1km/hr the power of the motor is
1kW/20 = 50W.
 Two propulsion units are desired in order to have reliability and redundancy purpose. Since it
doesn’t put too much load on single propeller.
 The two propulsion units will draw 100W from the batteries.
 In case of worst scenario, a single propulsion unit is designed to be capable to propel and steer the
boat.
9.5. Ground Architecture
The ground system architecture describes the interface between the end users and the space segment. It
comprises overall operations, science operations and the communications uplink and downlink process.
The most iconic hardware system in a ground station is the radio antenna, which is capable of receiving
and transmitting electromagnetic waves to and from the Titan Boat and its orbiter. The ground architecture
will be extremely similar to that used on NASA’s Dawn mission per the below figure (Polanskey 2011).

31. 28
Figure 28: Ground architecture for the Dawn Mission on which the Titan Boat Mission is based
The Deep Space Network (DSN)
The DSN includes three ground stations which are located in USA, Australia and Spain. The DSN is used
for interplanetary missions so it is ideal for the Titan Boat mission. Each ground station consists various
34m and one 70m diameter antenna platforms. Separate platform can be collect together to perform a
wider downlink area. Every platform has a control centre and a group of technical staff to link with deep
space network control centre and each space mission control centre to offer tracking assistances. In each
ground station, 34 m antenna platforms are mainly used for Dawn mission. And the 70m antenna platform
is only used transfer data which requires high reliability. Also, 70m antenna platform is an optimized choice
when receiving downlink data from spacecraft low gain antenna.
Dawn science operations are managed by the Science Operations Support Team at University of
California, Los Angeles (UCLA). They design the science operations processes and procedures, and
troubleshoots instrument issues.
During the uplink process, the science team defines science objectives which are passed to the
instruments team. The instruments team defines activities that meets these science objectives and passes
this plan to DSC and checks that the plan can be implemented within available spacecraft resources
(memory buffers, downlink capability etc). Mission planners review the plan to verify that sufficient margin
remains for spacecraft engineering activities such as orbit maintenance, optical navigation, and downlink.
During the downlink process, telemetry is captured by the Deep Space Network (DSN). The data is then
transferred to JPL. After a process of decompressing, decoding and formatting the data sets and is stored
in the Science Database (SDb). The science team can also create details Geographic Information System
products like maps and mosaics. The data is then delivered and archived for distribution to the broader
scientific community and the public.
Support from European Space Agency

32. 29
In addition to NASA’s DSN, the European Space Agency (ESA) tracking station, including Kourou, South
America and Perth station, are also used since the Titan Boat mission is a cooperative mission between
these two organisations. The ESA tracking station supplements are followed:
 X-band communication.
 Navigation symbol recording.
 Integration of management with deep space network.
 Data line connection with Jet Propulsion Laboratory
 Voice connection with Jet Propulsion Laboratory

33. 30
10. Propulsion Subsystem Analysis
10.1 Statement of Works
The Statement of works is a formal document for the prime contractor to develop and manufacture the
propulsion units for the Titan Boat. It includes the requirements, terms and conditions of their contractual
obligations.
10.1.1 Purpose
The purpose of the propulsion system is to propel the Titan Boat on Ligeia Mare with high reliability based
on periodic instructions sent by the Science operations teams.
10.1.2. Scope of work
The scope of work involves the design and manufacture of two electric propulsion units according to the
requirements described in section 10.1.7. followed by user, operational and integration testing.
10.1.3. Main entities
The user of this system is NASA and the prime contractor is Lockheed Martin as identified in section 4.
10.1.4. Location of work
The location of work includes software coding by NASA at JPL laboratory, manufacturing by Lockheed
Martin and its sub-contractors around the word and integration and testing at JPL, ESA and the Kennedy
Space Centre.
10.1.5 Period of Performance
The total period of performance is from October 2020 to April 2028. The propulsion system must survive
launch and a minimum of seven years of interplanetary travel to Titan. It must then survive atmospheric
entry and splash down on Ligeia Mare. Following this it must reliably operate for at least 100 days, starting
from the Titan Boat landing on Ligeia Mare.
10.1.6. Deliverables Schedule:
Phase Time line Entities/ principals Procedure
A 2015 to 2016 NASA, ESA
NASA to provide operational concept and
functional requirements
B 2016 to 2018 NASA, JPL, ESA
NASA, JPL to supply Lockheed Martin with
preliminary detailed specifications

34. 31
C 2018 April to July Lockheed Martin
Design and analysis conducted by Lockheed
Martin
C 2018 August
Lockheed Martin, NASA,
JPL, ESA
Critical Design Review
D 2018 September to March Lockheed Martin Manufacture
D 2019 April to May Lockheed Martin Assembly
D
2019 June to 2020
January
Lockheed Martin, NASA,
JPL, ESA
Test
10.1.7. Applicable Requirements
Figure 29: Requirements for Propulsion subsystem
10.1.8. Acceptance Criteria
In order for the final product to be accepted a number of tests must be passed. At a minimum, NASA and
its partners will examine if this system achieves all its functional requirements.
User acceptance testing
The science and mission operations team at JPL will conduct tests to validate that the propulsion system
behaves as they instruct and that any bugs or failures on the propulsion system to obey the commands of
the operations teams are rectified before the propulsion system is accepted.
Operational acceptance testing

35. 32
Lockheed martin must supply operational test results to NASA to demonstrate that it meets the functional
requirements. To replicate the conditions experience by the propulsion system during its period of
performance the following tests must be conducted by Lockheed Martin
 Launch simulation
 Deep space travel simulation
 Heat and cold tolerance testing
 Splash down simulation
 Titan environment simulation
 Physical damage testing
 Software testing
 Fault testing and resolution
NASA and its partners will then conduct its own independent verification tests by. Should this test be
passed then the operational acceptance testing phase is complete.
10.1.12. Type of Contract/Payment Schedule
NASA will provide one out of three part of the total value of the contract to Lockheed Martin as start-up
capital. After successful validation and verification from NASA, NASA will transfer the remaining money to
Lockheed Martin. Any schedule slippages will result in penalties to Lockheed Martin. A performance
incentive bonus will be paid to Lockheed Martin if the Propulsion system passes all testing and is delivered
earlier than the contracted deadline. This amount will be paid as a fixed sum per week for the number of
weeks the propulsion system is delivered ahead of schedule.
10.2 Fault Tree Analysis
Fault tree analysis (FTA) allows for the understanding of the logic leading to a fault event and the
prioritisation of those causes. It is a proactive tool used to prevent fault events occurring as well as a design
evaluation tool (NASA 2002). It must be emphasised that it is not an exhaustive description of failures.
Instead an FTA should describe faults that are realistically expected. The first step in FTA is to describe the
objective for creating one. In this case the objective is to evaluate and further enhance the design of the
Titan Boat propulsion sub-system. The next step is to define the boundaries of the FTA. In this case only
the landing and science operations are considered. The manufacturing, assembly and launch operations
for the Titan Boat are excluded. The orbiter is completely excluded.

36. 33
Figure 30: Fault Tree Analysis: operational but inaccurate direction
Figure 31: Fault Tree Analysis: Operational but less thrust than expected
CDHS
failure
Operational but
inaccurate direction
Propulsion subsystem
Hardware damage
Sensor
Hardware issue
Software issue
Communications
interruption
Titan weather
interference
Titan-Earth
access
Titan-orbiter
access
Wrong command sent
By operations team
Data corruption
on CDHS memory
Heat shield
failure
Camera hardware
Issue
Expected location of
Titan boat is incorrect
Onboard location
beacon failure
Data correct but incorrect
interpretation of the data
Miscalculation by
Operations team
CDHS software
glitch
Environmental
contamination
No
Power
Mechanical
damage
During descent and
landing operations
During science
operations
Software
glitch
Collision with
the environment
Parachute
failure
Cyclic loading
beyond design
Thermal stress
fatigue beyond design
PROPULSION SYSTEM
FAULT TREE
Non-operational Operational but less
thrust than expected
Damage to propulsion
blades
Insufficient
power
Software
issue
Power gen.
degradation
Battery storage
issue
Electrical distribution
issues
CDHS
failure
Wrong command sent
By operations team
Data corruption
on CDHS memory
Software
glitch
Operational but
inaccurate direction
PROPULSION SYSTEM
FAULT TREE
Non-operational Operational but less
thrust than expected

37. 34
Figure 32: Fault Tree Analysis: Non-operational
10.3. Preliminary Failure Mode, Effects and Criticality
Analysis (FMECA)
FMECA is used to help the contractor , Lockheed Martin to find the likely failure status, and relative causes
and following outcomes in system design stage. Through failure mode analysis, contractors can identify the
reliable and safety design and modify the risk ones. This is because, each failure mode should be attached
with causes, effects, severity level, probable level, critically level, failure detection methods, short time
solution, long time solution and some critical comments which could give contractor a thorough
understanding of each likely failure modes’ capacity. The FMECA criteria are based on MIL-STD-1629A
(Department of Defence 1980). After FMECA analysis, designers could modify their projects to alleviate
dangerous and increase components or functions reliability. Also, the entire design time will be largely
reduced, due to identify and correct relative problems.
Classification scheme for the severity of effects of each failure mode
4. Catastrophic (Death or system loss)
3. Critical (Severe injury, occupational illness, or system damage)
2. Marginal (Minor injury, occupational illness, or system damage)
1. Negligible (Less than minor injury, occupational illness, or system damage)
Estimate probability of failure mode.
4. Probable (Likely to occur immediately or within a short period of time)
3. Reasonably Probable (Probably will occur in time)
2. Remote (Possible to occur in time)
1. Extremely Remote (Unlikely to occur)
Communications
failure
No power Catastrophic failure
Explosion from naked spark in
methane environment
Power generation
failure
Battery storage
failure
Electrical distribution
short circuit/leak
Does not receive
commands
Receives commands
but cannot take action
CDHS
failure
Antenna system
failure
Connection between
antenna and CDHS failure
Operational but
inaccurate direction
PROPULSION SYSTEM
FAULT TREE
Non-operational Operational but less
thrust than expected

38. 35
Table 9: Failure Mode, Effects and Criticality Analysis
Function Failure modes Causes of failure Failure effects Severity Probability Criticality
Failure
detection
methods
Immediate
intervention
Long term intervention Comments
1
Communication
1.1
Communication
interruption
 Titan weather
interruption
 Titan
atmosphere
interruption
 Titan orbital
interruption
No functional signal
receiving
2 4 8
Detect
through
frequently
signal
comparison
Stop instruction
distribute and transfer
Titan Boat to auto-
drive mode
 Deploy different
antenna to work
in various
frequency
communication
mode
 Periodically
check
communication
packet loss
probability
Probably
occur but not
deadly
1.2 No
command
received
 Antenna
system failure
 Data
transmission
failure
No message transfer 2 4 8
Periodically
check the
system
hardware
working
condition
feed back
Check each node of
communication link to
find problem or try to
contact the station
 Deploy at least
one
communication
subsystem as
backup
frequently to
occur , not
deadly
indeed
1.3 No valid
action under
command
instruction
 Data
transmission
lose because
of hardware
fault
 Propulsion
structure
damage
Communication will be
affected or have to
replace the hardware
4 2 8
Periodically
system
conduct
system
self-check
Start backup system
mode (including back
up circus, propulsion
facilities)
 Deploy
programmable
logic controllers
to modify
system working
mode
 Deploy high
reliable
hardware
Fatal and
hard to
correct
2 Cruise
2.1 No thrust
 Instruction
transmission
failure
 propulsion
blade
damage(erosio
n, structural
damage)
 power leakage
Titan Boat cannot cruise
on Mare sea
4 1 4
Periodically
system
conduct
system
self-check
Start backup system
mode (including back
up circus, propulsion
 Deploy robust
data and power
transmission
channel
 Increase
hardware
strength
Rare to occur
but deadly to
function
2.2 Collision
when shipping
 Failure to
detect barriers
on channel
 Data
transmission
error
 Structure
damage of
Titan Boat
 Inner
instruments
shock
3 1 3
Sensors
detect
unexpected
collision
and shock
Modify survey plan
and shipping lane
 Improve
reliability of auto
drive system
 Improve
structure
strength of Titan
Boat
Less chance
to occur

39. 36
2.3 Boat
capsize
 Shipping over
speed
 Bad weather
 Instrument
unreasonable
distribution
BT mission early
termination
4 1 4
Tilt sensor
send failure
mode
signal back
Using compensation
mechanism to keep
balance
 Decrease
gravity centre
when design
Unimpressive
but could
bring huge
catastrophe
2.4 Ship with
un wanted
speed
 Propulsion
blade damage
 Liquid Viscosity
change
Cannot achieve
preinstall mission
1 1 1
Periodically
location
detect
Calculate the failure
trend and modify
following mission
plan
 Increase blade
structure
strength
 Increase
navigation self-
revise ability
Could be
revise easily
in operation
3 Charging
3.1 Not enough
power supply
 Power
generation
failure
 Battery storage
failure
 Electrical
distribution
short
circuit/leak
Cannot achieve
preinstall mission
2 1 2
Periodically
status
check
 Check
power line
 Modify
power
allocation
quota
 Apply backup
power supply
system
Rare to
happen but
easy to
modify
3.2 No power
supply
 Power
generation
failure
 Battery storage
failure
 Electrical
distribution
short
circuit/leak
BT cannot cruise on
Mare sea
4 1 4
Periodically
status
check
Transfer to backup
power supply line
 Deploy robust
power supply
system
Rare to
happen but
deadly to
system
function
4 Navigation
4.1 Ship to un
wanted
direction
 Propulsion
blade damage
 Navigation
computer
failure
Titan Boat lost in
direction
2 1 2
Periodically
location
detect
Calculate the failure
trend and modify
following mission
plan
 Increase blade
structure
strength
 Increase
navigation self-
revise ability
Could be
revise easily
in operation

40. 37
10.4. Risk Matrix
The risk matrix is used for the assessing the safety of risk. It is the popular method for safety and decisions.
It helps in building the consensus. It is a formal and structured method easy to understand by the
managements. Risk matrix shows the uncertain and consequences of the product or the design and
highlights the damages/consequences with different levels of the uncertainty. It shows the probability of the
product success or the failure and to achieve the acceptable risks through a systemic approach of analysis
design a risk matrix throughout its life cycle (Ho 2010).
Table 10: Risk Matrix for the Titan Boat Propulsion System
Consequence
Negligible (1) Marginal (2) Critical (3) Catastrophic (4)
Probability
Probable (4)
1.1
1.2
2.1
Reasonably probable (3) 1.3
Remote (2)
Extremely remote (1) 2.4 3.1,4.1 2.2
2.3
3.2
Legend
Green: Acceptable risk
Yellow: Acceptable risk
Orange: Moderate risk
Red: Unacceptable risk
Classification scheme for the the severity of effects of each failure mode
4. Catastrophic (Death or system loss)
3. Critical (Severe injury, occupational illness, or system damage)
2. Marginal (Minor injury, occupational illness, or system damage)
1. Negligible (Less than minor injury, occupational illness, or system damage)
Estimate probability of failure mode.
4. Probable (Likely to occur immediately or within a short period of time)
3. Reasonably Probable (Probably will occur in time)
2. Remote (Possible to occur in time)
1. Extremely Remote (Unlikely to occur)

41. 38
11. Conclusion
Since the Cassini-Huygens mission, there have been numerous tantalising mysteries about Titan that wait
to be investigated. These can be summarised into two broad questions: ‘how conducive is the Titan
environment for life’ and ‘what is the lake topography and environment system’? Previous science missions
to Titan suggest that the compounds present in the atmosphere and surface could be supportive for
prebiotic conditions. Answering both these questions will further improve humanity’s understanding of life in
the solar system and the nature of life itself.
There is no better time for another mission to Titan. Indeed, the window for a low cost mission will close
beyond 2024 due to orbital inefficiencies. This report details a conceptual design by which such a mission
could be conceived. It leverages the enormous technology and operational heritage from previous Titan
missions to maximise mission success while simultaneously multiplying the investment return in science
value by incorporating the latest space vetted payload technologies.
This report demonstrates the conceptual design process for the Titan Boat’s 100 day mission on Ligeia
Mare, the second largest lake on Titan. The Titan Boat mission will launch in late 2020 and will arrive at
Titan late 2027. To maximise the scientific value during the 100 day mission the Titan Boat will have a
novel propulsion system driven by two 50W electric motors to slowly cruise on the surface of Ligeia Mare.
This report also develops a statement of works to approach the prime contractor, Lockheed Martin, to
develop the propulsion system. A preliminary fault analysis of the propulsion system is also conducted. This
methodology was used to perform several design revisions of the propulsion system.
This study confirms that the mission is ready to proceed to the next stage.

42. 39
Appendix
A.1. Team member contribution
Report Section Contributors
Executive Summary Jason
Background Hassan, Jason, Felix, Meiyappan
Mission statement Hassan, Jason, Felix, Meiyappan
Stakeholders Felix
Timeline Jason
System concept Hassan, Jason, Felix, Meiyappan
System concept CAD Jason
Concept of operations Hassan, Jason, Felix
Requirements: tree, block diagram and table Jason
System Architecture Meiyappan, Felix, Jason, Hassan
Launch vehicle Hassan, Jason
Orbits Jason
Payloads Felix
Subsystems Felix, Jason
Subsystem block diagram Felix
N2 Diagram Jason, Felix, Jason, Hassan
CDHS Jason
Structure Jason
ADCS Jason
Power Meiyappan, Felix, Jason, Hassan
Thermal Meiyappan, Jason
Communication Hassan, Jason
Propulsion Meiyappan
Ground Architecture Jason, Felix, Meiyappan
Statement of works Felix, Jason
Fault tree diagrams Jason
Risk Matrix Felix, Hassan
FMECA Felix, Hassan
Conclusion Jason
Report compiling, editing, formatting Jason
References Meiyappan, Felix, Jason, Hassan

43. 40
References
Wu J 2015, ‘Life ‘not as we know it’ possible on Saturn’s moon Titan’, accessed 6 April 2015,
<http://www.news.cornell.edu/stories/2015/02/life-not-we-know-it-possible-saturns-moon-titan>
NASA 2015, ‘The Pioneer Missions 2007‟, accessed 6th March, 2015,
<http://www.nasa.gov/centers/ames/missions/archive/pioneer.html >
NASA 2015, ‘Voyager the interstellar mission 2014’, accessed 6th
March, 2015,
<http://solarsystem.nasa.gov/missions/profile.cfm?Target=Jupiter&MCode=Voyager_1&Display=ReadMore
>.
NASA 2014, ‘Missions to Jupiter’, accessed 6th
March 2015,
<http://voyager.jpl.nasa.gov/science/saturn.html>.
Mack PE 2001, ‘From Engineering Science to Big Science’ , National Aeronautics and Space
Administration, accessed 6th
March 2015,< http://history.nasa.gov/SP-4219/Chapter11.html>.
Béghin C., Sotin C., Hamelin M, ‘Titan’s native ocean revealed beneath some 45k mof ice by a schumann-
like resonance’, Comptes Rendus Geoscience, Vol.342(6), pp.425-433.
Castillo-Rogez J, Lunine J 2010, ‘Evolution of Titan’s rocky core constrained by Cassini observations’,
Geophysical Research Letters, Vol. 37, article L20205.
Norman, LH and Fortes, AD 2011, ‘Is there life on ... Titan?’, Astronomy & Geophysics , Vol.52(1), pp.39-
42.
Grindrod PM, Fortes AD, Nimmo F 2008, ‘The long-term stability of a possible aqueous ammonium
sulphate ocean inside Titan’, Icarus, Vol.197, pp.137-151.
Lorenz RD 2002, ‘Thermodynamics of geysers: Application to Titan’, Icarus, Vol.156(1), pp.176-183.
Artemieva N 2003, ‘Cratering on Titan:Impact melt, ejecta, and the fate of surface organics’, Icarus,
Vol.164(2), pp.164:471.
Sarker N, Somogyi, A, Lunine, J and Smith MA 2003, ‘Titan aerosol analogues: Analysis of the non-volatile
tholins’, Astrobiology, Vol.3(4), pp.719-726.
Strobel D, ‘Molecular hydrogen in Titan’s atmosphere: implications of the measured tropospheric and
thermospheric mole fractions’, Icarus, Vol.208(2), pp.878-886.
Neish C 2007, Formation of prebiotic molecules in liquid water environments on the surface of Titan,
Proquest dissertations and theses, ProQuest, UMI Dissertations Publishing.
Neish C, Somogyi, A, Imananka H, Lunine, J and Smith MA 2008, ‘Rate measurements of hydrolysis of
complex organic macromolectules in cold aqueous solutions: implications for prebiotic chemistry on the
early earth and Titan’, Astrobiology, Vol. 8(2), pp. 273-287.
Neish C, Somogyi and Smith MA 2010, ‘Titan’s primordial soup: formation of amino acids via low-
temperature hydrolysis of tholins’, Astrobiology, Vol.10(3), pp.337-347.

44. 41
Clark RN et al., 2009, ‘Photometric changes on Saturn’s Titan: Evidence for active cryovolcanism’,
Geophysical Research Letters, Vol.36(4).
Cowen, Ron. Science News. 7/3/2010, Vol. 178 Issue 1, p1010. 2/5p
UNSW 2014, „The CASSINI -HUYGENS Mission: Origin and accomplishment‟, part of the lecture notes
distributed in ELEC9762 at the University of New South Wales, Kensington on April 2015.
Couzin P, Blancquaert T, Schipper AM, 2005, ‘Huygens Probe Design: Some Lessons Learnt’, Anavyssos,
Attica, Greece
Lebreton JP, Schipper AM, (n.d.) ‘Straight from Titan as if you were there: the first Huygens results’, part of
lecture notes distributed in ELEC9762 at the University of New South Wales, Kensington on April 2015.
NASA 2015, 'What is Space Radiation?', accessed 30 April 2014, <http://lws-
set.gsfc.nasa.gov/space_radiation.html>
BBC 2013, ‘Space: how cold does it get when we leave earth?’, accessed 19 April 2015,
<http://www.bbc.com/future/story/20130920-how-cold-is-space-really>
BBC 2014, ‘Waves detected on Titan’s moon’s lakes’, accessed 19 April 2015,
<http://www.bbc.com/news/science-environment-26622586>
Lunar and Planetary Institute 2012, 'Titan Mare Explorer: TiMe for Titan', accessed 20 April 2015,
<http://www.lpi.usra.edu/opag/mar2012/presentations/Friday/1_TiME_opag.pdf>
Bouilly JM 2005, 'Thermal protection system of the Huygens probe during Titan entry: Flight preparation
and lessons learned', accessed 20 April 2015, <https://solarsystem.nasa.gov/docs/37_bouilly_paper.pdf>
Stofan et al. 2010, 'Exploring the Seas of Titan: the Titan Mare Explorer Mission', accesed 20 April 2015,
41st Lunar and Planetary Science Conference <http://www.lpi.usra.edu/meetings/lpsc2010/pdf/1236.pdf>
JPL 1999, 'Cassini-Huygens Launch', accessed 20 April 2015,
<http://www.saturn.jpl.nasa.gov/files/launch.pd
Aharonson O, 2010, ‘TiMe: Titan Mare Explorer’, accessed 20 April 2015,
<http://www.kiss.caltech.edu/workshops/titan2010/presentations/aharonson.pdf>
Lebreton JP, Matson DL, 2002, ‘The Huygens Probe: Science, payload and mission overview’, Space
Science Reviews 104: 59-100
NASA JPL n.d., ‘About Saturn and its moons’, accessed 23 April 2015,
<http://saturn.jpl.nasa.gov/science/index.cfm?SciencePageID=75>
Clausen, KC et al, 1999, ‘ The Huygens probe system design’, Space Science Reviews 104: 155-189
Alcoa 2015, ‘Cryogenic and shipyard aluminium’, accessed 23 April 2015,
<https://www.alcoa.com/mill_products/north_america/en/product.asp?cat_id=1479&prod_id=615>
Maritime New Zealand, ‘A guide to fishing vessel stability’, accessed 23 April 2015, <
https://www.maritimenz.govt.nz/Publications-and-forms/Commercial-operations/Shipping-safety/Vessel-
Stability-Guidelines-A4.pdf>

45. 42
Take me fishing.org , 2015, ‘Types of Hulls’, accessed 23 April 2015, <http://takemefishing.org/boating/the-
boat-for-you/types-of-hulls/>
NASA 2002, ‘Fault Tree Handbook with Aerospace applications’, accessed 28 April,
<http://www.hq.nasa.gov/office/codeq/doctree/fthb.pdf>
Mast Cameras, accessed 27 April 2015, NASA
<http://mars.nasa.gov/msl/mission/instruments/cameras/mastcam/>.
Mahaffy, P 2013, „Sample Analysis at Mars‟, NASA, accessed 27 April 2015,
<http://mars.nasa.gov/msl/mission/instruments/spectrometers/sam/>.
Lebreton & Matson 2002, ‘THE HUYGENS PROBE: SCIENCE, PAYLOAD AND MISSION
OVERVIEW’, Space Science Reviews, Vol. 104, pp. 59-100.
Rover Environmental Monitoring Station n.d., accessed 27 April 2015, <http://msl-
scicorner.jpl.nasa.gov/Instruments/REMS/>.
Gómez-Elvira,J et al. 2015, ‘The Environmental Sensor Suite for the Mars Science Laboratory Rover’,
Space Science Reviews, No 170, pp.583-640, accessed 27 April 2015 from Proquest Database, ISSN;
0038-6308.
Osborne, B 2015, ‘Lecture 2’, lecture notes distributed in ELEC9762 at the University of New South Wales,
Kensington on April 2015.
Munsell, K n.d., ‘Cassini Solstice Mission’, NASA, accessed 29 April 2015,
<http://saturn.jpl.nasa.gov/interactive/missiontimeline/>.
A legacy of exploration 2013, accessed 27 April 2015, < https://solarsystem.nasa.gov/rps/rtg.cfm#gphsrtg>.
Rioux,N 2006, ‘ANSI/AIAA Guide for Estimating Spacecraft Systems Contingencies Applied to the NASA
GLAST Mission’, 2006 IEEE Aerospace Conference, accessed 27 April 2015 from IEEE Xplore Database,
ISBN; 0-7803-9545-X.
David H. Atkinson , Kamal Oudrhiri, Thomas R. Spilker, Kevin H. Baines, Sami Asmar, Bernie Bienstock,
Steve Sichi Dept. of Electrical and Computer Engineering, University of Idaho, Moscow ID 83844-1023,
USA, email: atkinson@ece.uidaho.edu
Satellite Communications Payload and System, Teresa, ISBN: 978-0-470-54084-8400 pages, August 2012,
Wiley-IEEE Press
Haviland, RP 1957, The Communication Satellite, Eighth International Astronautical Congress, Barcelona,
October 6-12, 1957.
JPL 2008, Space Radioisotope power system, accessed 2 May 2015,
<http://mars.jpl.nasa.gov/msl//files/mep/MMRTG_Jan2008.pdf>.
JPL 2015, ‘Power - Mars Science Laboratory’, accessed 02 May 2015,
<http://mars.jpl.nasa.gov/msl/mission/technology/technologiesofbroadbenefit/power/>.
Jiang, M 2013, ‘An overview of radioisotope thermoelectric generators’, acceseed 3 May 2015,
<http://large.stanford.edu/courses/2013/ph241/jiang1/>.

46. 43
Piazza, E n.d., ‘Hugens Probe Engineering Subsystems’, NASA JPL, accessed 22 April 2015,
<http://saturn.jpl.nasa.gov/spacecraft/huygensprobeengineeringsubsystems/>.
SpaceX 2015, ‘Capabilities and service’, accessed 2 April 2015,
<http://www.spacex.com/about/capabilities>
Tsafnat, N 2015, The Space Segment, lecture notes distributed in AERO9500 at the University of New
South Wales, Kensington on 10 April 2015.
Halpert, G and Anderson, A 1982, Lithium/Sulfur Dioxide Cell and Batter-v Safety, Goddard Space Flight
Center Greenbelt, accessed 15 May 2015,
<http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19830006413.pdf >.
Whisper Power n.d., Yacht Propulsion System / electrical, accessed 4 May 2015,
<http://www.nauticexpo.com/prod/hybrid-power-systems/yacht-propulsion-system-electrical-35659-
351596.html>.
Master Volt, 2015, Drive Master, accessed 4 May 2015
<http://www.nauticexpo.com/prod/mastervolt/boat-propulsion-system-diesel-hybrid-electrical-22060-
266598.html>
World Nuclear Association, 2014, Plutonium, accessed 4 May 2015, <http://www.world-
nuclear.org/info/nuclear-fuel-cycle/fuel-recycling/plutonium/>
Caponiti, A 2008, What is a multi-mission radioisotope thermoelectric generator, JPL, accessed 5 May
2015, <http://mars.jpl.nasa.gov/msl//files/mep/MMRTG_Jan2008.pdf>.
Bright Hub Engineering n.d., Electrical Propulsion System, accessed 4 May 2015,
<http://www.brighthubengineering.com/naval-architecture/27452-what-are-the-main-types-of-ship-
propulsion-systems/>
PHYS.ORG, April 2014, Let’s put a sailboat on Titan, accessed 4 May 2015, <http://phys.org/news/2014-
04-sailboat-titan.html>
Krcum.M, n.d., SHIP PROPULSION SYSTEM, accessed 4 May 2015,
<https://bib.irb.hr/datoteka/10968.krcum971.doc>
Eco boats, n.d., Electric boat motor, accessed 4 May 2015,
<http://www.ecoboats.com.au/productrange_bellmann.php>
Ho, V 2010, The Risk Of Using Risk Matrix for Assessing Safety Risk, Joint seminar of HKARMS, accessed
by 05 May 2015, <http://www.hkarms.org/web_resources/20101116_risk_matrix_hkieb_print.pdf>.
Department of Defence 1980, Procedures for performing a Failure Mode, Effects, and Criticality Analysis,
Washington.
Polanskey C, S.P. Joy, C.A. Raymond 2011, ‘Dawn science planning operations, and archiving’, Space
Science Review, 163:511–543.