Imaging and Localisation Package for a Martian Balloon Based Aerobot Dave Barnes, Andy Shaw, Phil Summers Roger Ward, Mark Woods, Malcolm Evans Gerhard Paar, Mark Sims ESA Contract No /03/NL/CH

Contents ILP overview Balloon gondola hardware Balloon localisation Balloon simulator The way forward

Balloon Imaging Mission

Imaging and Localisation Package The package will allow optimal acquisition of images to reconstruct accurate models of the surface of the explored planet, and accurate localisation of the balloon with respect to the Martian surface. The ILP by means of aerobot mounted cameras and computer vision techniques will: a) acquire and store images of the surface at various resolutions, b) construct and update a 3D model (DEM) of the surface, (cont..)

Imaging and Localisation Package c) constantly estimate the position (latitude, longitude and altitude) of the aerobot as well as its motion with respect to the surface, and d) decide on the base of the communications budget, of the morphology of the surface and of the information content of the images, which images at which resolution/compression need to be transmitted to Earth.

Image Acquisition Problem

Satellite Transmission Problem

SOW ILP Overview

Contents ILP overview Balloon gondola hardware Balloon localisation Balloon simulator The way forward

Hardware Overview Balloon envelope Propulsion system Altimeter Camera On-board processor Mock terrain

Balloon Lift A 1830 mm (  6 ft) diameter balloon will produce a total lift of 3 kg PVDC envelope mass =1 kg –Gondola mass = 2 kg Mylar envelope mass = 0.3 kg –Gondola mass = 2.7 kg

AVI - Early Propulsion System

Hardware Overview

Complete Gondola Structure

ILP Gondola Camera Calibration

Gondola Captured ESTEC PTB Image Mosaic

Contents ILP overview Balloon gondola hardware Balloon localisation Balloon simulator The way forward

Localisation Approach To maintain localisation accuracy over large aerobot flight distances, our ILP approach augments a relative localisation method with an additional global localisation approach.

Relative Localisation

Global Localisation FEATURE AND GRADIENT MATCHING METHODS USED Local Aerobot ILP Generated DEM

Global Orbiter DEM Showing Localised Balloon E.G. MGS MOLA DATA WITH EXTRACTED FEATURES

Contents ILP overview Balloon gondola hardware Balloon localisation Balloon simulator The way forward

Balloon Simulator Overview ILP Martian Balloon Simulator Terrain Data: MOLA, MOC, THEMIS Martian Meteorology: ESA MCDB & CFD Balloon Aerodynamics Model Gondola Instrumentation Model e.g. Camera

Balloon Simulator Screen Shot

Beagle 2 landing ellipse and crater ‘H’ Image courtesy THEMIS ASU Team and MSSS

Shape from shading – crater ‘H’

Balloon Simulator Overview ILP Martian Balloon Simulator Terrain Data: MOLA, MOC, THEMIS Martian Meteorology: ESA MCDB & CFD Balloon Aerodynamics Model Gondola Instrumentation Model e.g. Camera

3D Navier-Stokes Martian Wind

Contents ILP overview Balloon gondola hardware Balloon localisation Balloon simulator The way forward

Tethered Martian Balloon Study Martian Atmospheric Parameters? –Location, Temperature, Pressure, Wind Speeds Balloon Envelope Parameters? –Material, Density, Thickness, Permeability Balloon Tether Parameters? –Material, Density, Young’s Modulus, Balloon Altitude (500m) Rover (or Lander) Related Parameters? –Winch Mass (incl. electronics), Gas Storage Science Instrument Mass? –Instruments, Power, Communications, Electronics (1kg)

Innovative Balloon Lift Methods

Tethered Hybrid Balloon/Kite Experiments