slides - ACG at TAU

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Curiosity
The Robotic Rover on Mars
Aviel Atias
Omri Ben Eliezer
Yaniv Sabo
29/04/13
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Exploring Mars
Goals of Mars Exploring
• Signs of Life?
• Water
• Inspecting chemical elements
• Inhabitation of Mars?
• Weather and radiation
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Exploring Mars
History of Mars Exploration
• Since 1960
• 50 attempts, 21 of them succeeded
• Two older rovers are still on their mission
Types of Spacecrafts
• Orbiter
• Lander
• Rover
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The Curiosity Project
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Structure of Curiosity
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Structure of Curiosity
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Curiosity’s Brain
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Curiosity’s Brain
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Curiosity’s Brain
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Curiosity’s Brain
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Robotic Arm
• The rover has a 2.1 m long arm with holding five devices that can
spin through a 350-degree
• The arm makes use of three joints to extend it forward and to stow
it again while driving
• It has a mass of 30 kg and its diameter is about 60 cm
• Two of the five devices are contact instruments known as the X-ray
spectrometer (APXS), and the Mars Hand Lens Imager (MAHLI
camera)
• The remaining three are associated with sample acquisition and
sample preparation functions: a percussion drill, a brush, and
mechanisms for scooping, sieving and portioning samples of
powdered rock and soil
• The diameter of the hole in a rock after drilling is 1.6 cm and up to
5 cm deep
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Robotic Arm – cont.
• 5 degrees of freedom.
• Capable of surviving temperature range of [1280C, +500C]. Operating in [-1100C, +500C].
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MAHLI camera
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Navigation Cameras (Navcams)
• The rover has two pairs of
black and white navigation
cameras mounted on the mast
to support ground navigation
• The cameras have a 45 degree
angle of view and use visible
light to capture stereoscopic 3D imagery.
• These cameras support use of
the ICER image compression
format.
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Hazard Avoidance Cameras
• The rover has four pairs of black and white navigation
cameras called Hazcams—two pairs in the front and two
pairs in the back
• They are used for autonomous hazard avoidance during
rover drives and for safe positioning of the robotic arm on
rocks and soils
• The cameras use visible light to capture stereoscopic threedimensional (3-D) imagery
• The cameras have a 120 degree field of view and map the
terrain at up to 3 m in front of the rover
• This imagery safeguards against the rover crashing into
unexpected obstacles, and works in tandem with software
that allows the rover to make its own safety choices
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Hazard Avoidance Cameras - cont.
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How to land a robot on mars?
• The atmosphere is too thin for parachutes and
aerobraking alone to be effective.
• Some previous missions have used airbags to
cushion the shock of landing,
but Curiosity rover is too
heavy for this.
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The EDL (entry-descent-landing)
system
• During the entire landing phase, the vehicle
acts autonomously.
• This system is more than 20 times accurate,
compared to older landing systems.
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EDL phase 1: Guided entry
• The rover was folded up
within an heat shield that
protected it during the
atmospheric entry.
• The heat shield diameter is
4.5 m, which is the largest heat
shield ever flown in space.
• The heat shield experienced peak temperatures of up
to 2,090 °C.
• It reduced the velocity of the spacecraft from
approximately 5.8 km/s down to approximately 470
m/s, where parachute is possible.
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EDL phase 2: Parachute descent
• When the entry phase was complete and the capsule was
at about 10 km altitude, the supersonic parachute
deployed.
• The parachute has 80
suspension lines, is over
50 m long, and is about
16 m in diameter.
• The parachute is capable
of being deployed at Mach
2.2, and can generate up to
289 kN of drag force in the atmosphere.
• After the parachute was deployed, the heat shield
separated and fell away.
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Parachute descent (contd.)
• The Mars Reconnaissance Orbiter team were
able to acquire this image:
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EDL phase 3: Powered descent
• At about 1.8 km altitude, still
travelling at about 100 m/s,
the rover and descent stage
dropped out of the aeroshell.
• The descent stage is a platform above the rover
with eight hydrazine rockets on arms extending
around this platform to slow the descent.
• Each rocket produces 400 N to 3,100 N of thrust.
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EDL phase 4: Sky crane landing
• The sky crane system lowered the rover on three nylon
tethers and an electrical cable carrying information and
power between.
• At 7.5 m below the descent stage the sky crane system
slowed to a halt and the rover touched down. After the
rover touched down, it waited 2 seconds to confirm
that it was on solid ground by detecting the weight on
the wheels and fired several pyros activating cable
cutters.
• The descent stage flew away to a crash landing 650 m.
• The sky crane powered descent landing system had
never been used in missions before.
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Sky crane landing (contd.)
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Thriller
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