Title: Executive Summary: Mission To Uranus Classification: Unclassified Issue: 1 Date: 15/09/2014 Contact: University of Leicester Department of Physics & Astronomy Space Research Centre University Road Leicester LE1 7RH UK Chris Greenaway, Jack Boughton, Prepared by: Date: 15/09/2014 Nils Dittel Reviewed by: N/A Date: N/A Approved by: N/A Date: N/A Executive Summary: Mission to Uranus Page i DOCUMENT CHANGE DETAILS Issue Date Page Description Of Change Comment 1 15/09/2014 N/A – First issue Executive Summary: Mission to Uranus Issue: 1 15/09/2014 Page ii TABLE OF CONTENTS 1.1 Reference Documents ............................................................................................................................ 1 1.2 Work Breakdown ................................................................................................................................... 5 2 The Icy Giant.................................................................................................................................................. 6 2.1 Science Objectives and Justification ........................................................................................................ 6 2.1.1 The atmosphere ............................................................................................................................... 6 2.1.2 The interior of Uranus ...................................................................................................................... 7 2.1.3 The Rings of Uranus ........................................................................................................................ 7 2.1.4 The unusual magnetic field: .............................................................................................................. 8 2.2 Icy Giant Matrix .................................................................................................................................. 11 3 The Uranian System ...................................................................................................................................... 13 3.1 Science Objectives and Justification ...................................................................................................... 13 3.1.1 The Natural Satellites ..................................................................................................................... 13 3.1.2 Natural Satellite Observation Priority Classification ......................................................................... 17 3.2 The Uranian System Matrix .................................................................................................................. 18 4 Model payload .............................................................................................................................................. 19 4.1 IR mapping Spectrometer ..................................................................................................................... 20 4.2 Radio science experiment ..................................................................................................................... 20 4.3 Microwave Radiometer ........................................................................................................................ 21 4.4 UV Spectrometer ................................................................................................................................. 22 4.5 Narrow Angle Camera .......................................................................................................................... 23 4.6 Wide Angle Camera ............................................................................................................................. 24 4.7 Magnetometer ..................................................................................................................................... 24 4.8 Plasma Particle Detector ....................................................................................................................... 25 5 Mission Design ............................................................................................................................................. 27 5.1 Reference Mission ............................................................................................................................... 27 Executive Summary: Mission to Uranus Issue: 1 15/09/2014 Page iii 5.2 Analysis .............................................................................................................................................. 28 6 Launch Vehicle ............................................................................................................................................. 32 6.1 Overview & Preliminary Selection ........................................................................................................ 32 6.2 Characteristic Energy Analysis.............................................................................................................. 33 6.3 Characteristic Energy Analysis Results .................................................................................................. 36 6.4 Summary ............................................................................................................................................ 37 7 Propulsion .................................................................................................................................................... 38 7.1 Requirements ...................................................................................................................................... 38 7.2 General Architecture Options ................................................................................................................ 38 7.3 Analysis .............................................................................................................................................. 40 8 Attitude Control System ................................................................................................................................ 44 8.1 Requirements and Attitude Determination .............................................................................................. 44 8.2 Reaction Wheel(s)................................................................................................................................ 44 8.3 Thrusters ............................................................................................................................................. 46 8.4 Overview ............................................................................................................................................ 48 9 Command and Data Handling ........................................................................................................................ 49 9.1 Telecommand message standards .......................................................................................................... 49 9.2 Instrument Processing Requirements ..................................................................................................... 50 9.3 compression ........................................................................................................................................ 51 9.4 ICER image Compression..................................................................................................................... 52 9.5 Digital Modulation and forward Error Correction ................................................................................... 53 9.6 Processor and data storage .................................................................................................................... 54 10 Communications ........................................................................................................................................... 56 10.1 Mission Communications overview ....................................................................................................... 56 10.2 Communication Subsystem Requirements and Constraints ...................................................................... 57 10.2.1 Telemetry Requirements ................................................................................................................ 57 Executive Summary: Mission to Uranus Issue: 1 15/09/2014 Page iv 10.2.2 Tracking Requirements .................................................................................................................. 57 10.2.3 Command Requirements ................................................................................................................ 57 10.2.4 Fault Protection and Reliability Requirements .................................................................................. 58 10.3 RF Vs Optical Trade-Off ...................................................................................................................... 58 10.4 Ground stations and Downlink Window ................................................................................................. 59 10.41 Ground station network choice .............................................................................................................. 59 10.42 Deep Space Network Coverage ............................................................................................................. 60 10.43 Spacecraft orbit...................................................................................................................................