Post on 14-Aug-2018
Jet Propulsion LaboratoryCalifornia Institute of Technology
Mars 2020 Project
© 2015 California Institute of Technology. Government sponsorship acknowledged.
Pre-Decisional: For Planning and Discussion Purposes Only.
Preliminary Traverse Distance
Estimates for Sites
Landing Site Workshop #2
8/4/2015 – 8/6/2015
Matt Heverly
Hiro Ono
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
• Hiro Ono
• Andreas Huertas
• Eduardo Almeida
• Brandon Rothrock
• Adnan Ansar
Team
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
• Relative comparison of traverse distance required at
each site to achieve a representative mission scenario
Objective
Mars 2020 Project-3
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
• Team at JPL interpreted the submitted ROIs to define a representative
scenario for exploring each site.
– Each site requires exploration of two ROIs for this exercise
– Some ROIs are now defined as the contact between geological units
• ROI definition and “must visit” set have a big impact on traverse requirements
at the site. We will work with science and site proposers to refine the ROI
definitions as we move forward.
Regions Of Interest (ROIs)
Mars 2020 Project-4
NE SyrtisAny one of the ROIs 1 through 6
&
Any one of 1, 2, 4, or 6 that you didn't visit above
McLaughlin CraterAny point on the contact between ROI #1 and #2
&
ROI #3
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
• Minimize distance to
achieve the minimum
ROI requirement from a
given landing point
• Optimal route computed
by the newly developed
Sequential Dijkstra
algorithm
Optimal Route Planning
Mars 2020 Project-5
3
5
6
2
4
1
Landing point
Example: NE Syrtis
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Optimal Route Planning
Mars 2020 Project-6
3
5
6
2
4
1
• Minimize distance to
achieve the minimum
ROI requirement from a
given landing point
• Optimal route computed
by the newly developed
Sequential Dijkstra
algorithm
Landing point
Example: NE Syrtis
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Optimal Route Planning
Mars 2020 Project-7
3
5
6
2
4
1
• Minimize distance to
achieve the minimum
ROI requirement from a
given landing point
• Optimal route computed
by the newly developed
Sequential Dijkstra
algorithm
Landing point
Example: NE Syrtis
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Monte-Carlo Simulation
Mars 2020 Project-8
Landing points
provided by EDL
team
Consists of
8,000 samples
Optimal route
computed from
all samples
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Cumulative Distribution of Distance
Mars 2020 Project-9
50th percentile distance: 7.8 km
90th percentile distance: 11.2 km
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Inputs to Analysis
Mars 2020 Project-10
Traversability
HazardsSlope
Rock
Abundance
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
NE Syrtis
Jezero
Nili Fossae Trough
Holden
McLaughlin
SW Melas
Mawrth
E Margaritifer
Data Availability
Mars 2020 Project-11
Hazard Slope Rock
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Hazard Map
Mars 2020 Project-12
Non-Traversable
Benign Terrain
Complex Terrain
Would not choose
to traverse
Example: NE Syrtis• Manual assessment
by Heverly
• Use HiRISE mosaic
with 1m resolution
• Assume that red and
orange are
untraversable
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Slope Map
Mars 2020 Project-13
Example: SW Melas
• Generated from
HiRISE DEMs
• 1m resolution
• Typically does not
cover the entire ellipse
• Threshold: 12°based
on MSL’s experience
on soft soil
5°- 10° 10°- 15° 15°- 20° 20°- 25° >25°
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Rock Abundance (CFA) Map
Mars 2020 Project-14
>=20%15%-20%10%-15%7%-10%
• CFA = cumulative fraction
of area covered by rocks
• Based on rock counts on
HiRISE images
• Automated rock detection
algorithm by A. Huertas
• 15% threshold based on
simulation
Example: SW Melas
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Combined Traversability Assessment
Mars 2020 Project-15
Example: NE Syrtis
• Use all available data
for each site
• Assume conservative
thresholds on slope
and rock abundance• 12 deg for slope
• 15% for CFA
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
• To get an estimate of fidelity traverse distance estimation was done in
the same way for Gale Crater
• Route planner shows 30% less distance than actual vehicle odometry
between Yellowknife Bay and Pahrump
Gale Crater Example
Mars 2020 Project-16
Actual traverse from Yellowknife
Bay on sol 324 to arrival at
Pahrump Hills on sol 753 has
vehicle odometry of 8.6km
Route planner from orbital data
gives 6.4 km (under estimate of
~30%)
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Results
Mars 2020 Project-17
50% 90%
NE Syrtis 10.1 km 14.6 km
Jezero Crator 11.3 km 16.8 km
Nili Fossae 13.1 km 17.6 km
Holden (Land-On) 12.2 km 16.4 km
McLaughlin Crater 8.7 km 13.5 km
SW Melas 8.3 km 12.6 km
Mawrth Vallis 3.5 km 8.5 km
E Margaritifer 3.3 km 5.7 kmValues represent potential vehicle odometry and
include 30% increase over map distance
• Clear difference between
“go to” and “land on” sites
• Placement and number of
required ROIs has a big
impact on traverse distance
• Work to go to mature these initial
estimates• More traversability data for each of
the sites
• Refined ROI definitions
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Backups
Mars 2020 Project-18
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Mars 2020 Project-19
Slope: Binary Travsersability
Threshold: 25°
Assumption: Slope above threshold
is untraversable
Example: SW Melas
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Mars 2020 Project-20
Threshold: 12°
Assumption: Slope above threshold
is untraversable
Slope: Binary Travsersability
Example: SW Melas
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Mars 2020 Project-21
Slope: Sensitivity
Conservative Assessment Optimistic Assessment
Sensitivity analysis by E. Almeida
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
CFA: Binary Travsersability
Mars 2020 Project-22
Example: SW Melas
Threshold: 15%
Assumption: CFA above threshold
is untraversable
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
CFA: Binary Travsersability
Mars 2020 Project-23
Example: SW Melas
Threshold: 10%
Assumption: CFA above threshold
is untraversable
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Mars 2020 Project-24
Rock Abundance: Sensitivity
Conservative Assessment Optimistic Assessment
Sensitivity analysis by E. Almeida
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Assessment Types
Three assessments are performed for each site
Conservative Assessment
Optimistic Assessment
No-Hazard Assessment
Mars 2020 Project-25
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Conservative Assessment
Mars 2020 Project-26
Example: NE Syrtis
• Use all available data
• Assume conservative
thresholds on slope and
rock abundance
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
Optimistic Assessment
Mars 2020 Project-27
Example: NE Syrtis
• Use all available data
• Assume optimistic
thresholds on slope and
rock abundance
Mars 2020 Project
Jet Propulsion LaboratoryCalifornia Institute of Technology
© 2015 California Institute of Technology. Government sponsorship acknowledged.Pre-Decisional: For Planning and Discussion Purposes Only.
No-Hazard Assessment
Mars 2020 Project-28
• Assuming that the entire
site is traversable
• Gives lower bound on
distance to achieve
scientific success
• Allows to compare sites
on the same basis
Example: NE Syrtis