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Aerobots for Planetary Exploration Dave Barnes Head of Space Robotics Department of Computer Science Aberystwyth University. Planetary Exploration Methods: Orbiters – MGS, Mars Express Landers – Viking Lander I, II, Beagle 2 Rovers – Spirit, Opportunity, ExoMars
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Aerobots for Planetary Exploration Dave Barnes Head of Space Robotics Department of Computer Science Aberystwyth University
Planetary Exploration Methods: Orbiters – MGS, Mars Express Landers – Viking Lander I, II, Beagle 2 Rovers – Spirit, Opportunity, ExoMars Aerobots – Flying robots (The Future)
Aerobot Advantages: High resolution surface imaging Can touch (land) as well as see (image) Landing site selection Rover guidance Data relay Sample site selection Payload delivery and surface science Atmospheric science Can go where rovers cannot!
Aerobot Challenges: Mass/volume/power (always a challenge!) Aerobot deployment (HTA versus LTA) Constantly changing environment Localisation Correlate science with Lat./Long./Alt.
Localisation Challenge: No GPS! Cannot always see the stars Anomalous localised magnetic regions Cannot commit orbital resources full time Cannot commit terrestrial “ “ “ Line-of-sight not always possible
Local Aerobot Generated DEM FEATURE AND GRADIENT MATCHING METHODS USED
Local DEM (Aerobot) Global DEM (Orbiter)
Global DEM DemoShell
Acceptance Trials at the ESA ESTEC Mars Yard Facility
Displaced_Mars_atmosphere_mass × Mars_gravity = Total_balloon_mass × Mars_gravity Kg Balloon lift in this region Tethered Aerobot Payload Calculations: Point of N.B. millimetres Neutral Buoyancy (N.B.) Example
Mass of Balloon Envelope Mass of Helium in Envelope Mass of Displaced atmosphere Neutral Buoyancy Equation: ρA = Density of Martian atmosphere ρHe = Density of Helium on Mars ρE = Density of envelope Et = Thickness of envelope Mscience = Mass of science Mtether = Mass of tether Mnotional = Contingency mass radius = Envelope radius
Assume a) High Density Polyethylene (HDPE) envelope b) Tether is made from Kevlar-49 material c) 20% mass contingency (Use Ideal Gas Law to calculate atmosphere and Helium densities on Mars) Engineering Data: For a given envelope radius and tether length (i.e. balloon altitude in Km), then the mass of the science payload can be calculated: 20% contingency
The Next 50 years (or less!): Aerobots will be used routinely for planetary exploration Aerobots will work with surface resources (e.g. rovers) Aerobots will be used on Mars, Titan, Venus Aerobot swarms (‘flocks’) will be used