1. Goals
Our primary goal was to develop various mission opportunities
to minor planets of interest past Neptune. These missions
ideally utilized a swing-by of Jupiter to assist our spacecraft on
its journey farther into Deep Space.
Our secondary goal was to develop the scientific objectives for
each mission and the spacecraft capable of meeting those
goals.
Constraints
As with all space related missions, there were many
constraints that were taken into consideration. The primary
ones for this project were:
 Mission Duration: Limited mission length to ~25 years to
avoid lack of continuity of scientists and engineers
 Radiation: Determine amount of radiation based on mission
 Weight: Limited payload weight based on launch vehicle
 Illumination: Determine if objects will be visible at arrival
 Power: Determine if enough power can be produced for the
long mission duration
Terms and Definitions
 AU: Astronomical Unit (~93 million miles)
 GCR: Galactic Cosmic Rays
 HILTOP: Heliocentric Interplanetary Low-Thrust Optimization
Program
 I: Intensity
 MAnE: Mission Analysis Environment
 OLTARIS: Online Tool for the Assessment of Radiation in
Space
 POST: Program to Optimize Simulated Trajectories
 RJ: Jovian Radii
 RTG: Radioisotope Thermoelectric Generators
 SPE: Solar Proton Event
 SPENVIS: Space Environment Information System
 TOF: Time of Flight
 TNO :Trans-Neptunian Object
Mission Opportunities to Trans-Neptunian Objects: Part V
Illumination
Illumination is solely
dependent on the
Inverse Square Law. The
intensity (I) of a light
source decreases with the
square of the distance
from the source.
Based on the illumination
of Earth from a full moon,
the objects of interest are
sufficiently illuminated by:
Instrumentation
The instruments for our spacecraft were selected from other
successful space missions, primarily New Horizons.
Power
Many recent missions including Cassini, New Horizons and
Mars’ Curiosity Rover have used Radioisotope Thermoelectric
Generators (RTGs).
An RTG uses a radioactive power source, normally Plutonium-
238 (Pu-238).
Based on the mission duration range and a maximum power
usage similar to New Horizons (180W), the amount of initial Pu-
238 will not exceed the amount of Pu-238 available.
The power consumption by the selected instruments for our
mission will be less than the maximum power usage by New
Horizons.
Therefore, the calculations using 180W have a significant
factor of safety.
Results
MAnE is a software program used to develop mission
trajectory based on when the Earth-Jupiter-TNO system is in
possible alignment using realistic launch and arrival speeds.
Using possible scenarios from previous TNO groups, the
missions were all re-developed and analyzed to optimize the
most important factors: mission duration, arrival speed, and
launch payload.
The program HILTOP was used to run low thrust missions.
The data was compared to the high thrust results and it was
found that low thrust missions have consistently lower
payload masses.
The main restriction to low thrust missions was the power
necessary to run the low thrust engines. As the satellite travels
farther out, solar panels are unable to provide the needed
power to operate the ion engines.
Low thrust will not be viable as an option for missions past
Jupiter until low thrust propulsion technology or energy
production technology advances further.
Radiation
Galactic cosmic rays (GCR), solar proton events (SPE), and
Jupiter’s massive radiation field are the most notable sources.
GCR radiation is caused from the solar system’s bow shock as
it travels rapidly through our galaxy. Because of this, the dose
from GCR is essentially constant. By utilizing the NASA server
and OLTARIS software, dosage of radiation originating from
GCR was determined to be negligible.
SPE can also be viewed as negligible due to the pure
randomness of the occurrence. If a SPE were to occur, the raw
dosage may be enough to melt the instrumentation regardless
of shielding.
Two software packages, POST and SPENVIS, were able to fully
analyze the ideal trajectories created. The dose limit for our
instrumentation is approximately 20-50 kilorads.
Our modeled results show, at 3 millimeters of shielding, the
radiation dose is approximately 1 kilorad. This is well within
the dose limitations. This fact validates the radiation
plausibility of our missions.
Final Missions
Two final missions were ultimately selected from 148 viable
missions.
Nearly all excess weight for mission 1 will be used in the
impactor. Mission 2 provides an excess weight of around 800
kg that can be used to expand the scientific instrumentation or
to try to slow down the craft for a longer stay at the secondary
target.
Impact Dynamics
An impact mission at Haumea will tell us the surface
composition of the dwarf planet and will allow us to get close
up pictures of the planet as the impactor approaches the
surface.
The flyby spacecraft will take pictures of the impact crater and
the instrument ALICE will be used to analyze the chemical
composition of the ejecta plume created from the impact
explosion.
The impactor will be released from the spacecraft 54 hours
before impact. The impactor will remain at 12.93 km/s, but the
flyby spacecraft will perform a burn to deflect around the
planet and will slow down its velocity to 12.79 km/s.
The impactor has a mass of 350 kg and is equipped with an
Impactor Targeting Sensor which allows pictures to be taken of
the surface of Haumea until impact.
The impact will explode with the same force as 6 tons of TNT.
Instruments Purpose Used On
ALICE • Ultraviolet Imaging
Spectrometer
• Analyzes composition of
atmosphere and debris
• New
Horizons
• Rosetta
Ralph • Visible and Infrared Imaging
Spectrometer
• Map Surface Temperature
• Map Surface Composition
• New
Horizons
LORRI • Long Range Reconnaissance
• Encounter Data at long
distances
• New
Horizons
REX • Determine Nighttime Thermal
Emissions
• Determine mass of objects
• Look for atmosphere
• New
Horizons
• CONTOUR
Object Distance from Sun Illumination (Compared
to Earth from full moon)
Huya 34 AU 346x brighter
Quoaor 42 AU 226x brighter
Haumea 46 AU 189x brighter
Brandon Davis, Ben Dolmovich, Meghan Green, Amanda Williams, Gerard Wise
Advisor: Dr. James Evans Lyne (jelyne@utk.edu)
Special Acknowledgement: Dr. Jerry Horsewood of SpaceFlightSolutions
Mission 1: Haumea
Mission 2: Huya and Quaoar
TNO
Flight
Time
(years)
V∞
Departure
(km/s)
RJ
Distance
(AU)
TNO
Arrival
Date
V∞ at
Arrival
(km/s)
Payload
(kg)
Haumea 16.45 11 12.27 45.86 4/11/55 12.93 1017.4
Primary
TNO
TOF
(years)
Secondar
y TNO
TOF
(years)
V∞
Departure
(km/s)
V∞
Arrival
(km/s)
ΔV at TNO
(km/s)
V∞
Arrival
(km/s)
Payload
(kg)
Huya 19.86 Quaoar 26.74 9.51 5.48 1.4732 5.84 1844.8
Mission 2: Huya/Quaoar – Launch date 11/21/2027 – Huya is 34
AU away and Quaoar is 42 AU away
Mission 1: Haumea – Launch date 10/29/2038