Team Force Field Leslie Chapman Scott Cornman Adam Johnson Richard Margulieux Brandon Phipps

Presentation Outline  Introduction  Mission Objectives  Background Mission  Mission Profile  Trade Tree  Spacecraft  Mission Profile  Lander  Orbiter  Communication Link and Command & Data Handling  Advantages

Introduction Mission Objectives Primary Objectives –Determine the trajectory of Apophis –Determine the seismology of Apophis Secondary Objectives –Laser mapping of Apophis –Close imaging of Apophis

Introduction Galileo –Successful approach of 951 Gaspra, 243 Ida and Dactyl –Solid state imager, Near IR spectrometer Dawn –3 DS1 Xenon Ion Engines, 3 Visual sensors, Visual and IR spectrometer, Gamma Ray and Nuetron spectrometer Phobos 1,2 –Unsuccessful study of Phobos and Deimos –Two landers, hopper, long-lived, spectrometer, seismometer, penetrometer –Orbiter houses IR, visual, Near IR spectrometer, Gamma, X-ray sensors Deep Impact –Successful flyby and impact event of comet 9p/Tempel, extended mission to 85P/Boethin –High Resolution Imager, Medium Resolution Imager, Impactor Targeting Sensor, Infrared Spectroscope –650kg/370kg impacter Past Missions

Introduction NEAR Shoemaker –Successful orbit and landing on Eros, communicated for 2 weeks before being shutdown –Mass: 487kg –Approach Distance: 200km, 35km, 5-6km, 2-3km, land at m/s –Reaction wheels and hydrazine thrusters, 1800 W solar power, Ni-Cd battery pack, IMU, gyros, sun sensors and star tracker –X-ray/gamma ray spectrometer, Near-infrared imaging spectrograph, Multi-spectral camera fitted with a CCD imaging detector, Laser rangefinder, Magnetometer, Radio science experiment to determine gravity field JAXA Hayabusa –Successful heliocentric orbit near and two close approaches to Itokawa, failed deployment of MINERVA, on return trajectory to Earth –Mass: 380kg (MINERVA: 591g) –Approach Distance: 20km, 44m, ? –4 Xenon Ion Engines, Reaction wheels (failed on orbit), thrusters –Multiband imaging camera, Laser altimeter, Near-infrared spectrometer, X-ray spectrometer Past Missions

Trade Tree Launch Vehicle Piggyback with Government Piggyback with Private LV Use exclusive LV

Trade Tree Propulsion Earth escape Rendezvous with Apophis ChemicalLow Thrust Solar Sails Electrical

Power Solar Fuel CellsNuclearRTG Trade Tree

Electric Cold Gas Chemical Momentum Devices Hall’s Effect ThrustersPPTBipropellantMono AugmentedTraditionalReaction WheelCMG 3-Axis Attitude and Translational Control Trade Tree

Proximity Operations Complete LanderComplete Stand-off Combination of stand-off to deploy Trade Tree

OrbitStand-off Complete Stand-off MultipleSingleMultipleSingle

Trade Tree Partial Deployment Main Lander with Orbiting Link Main Orbiter with Lander(s) Orbiter - Radios -Camera -Solar Panels Lander ― Transponder ― Camera ― Laser mapping device ― Seismology detector ― Radio ― Solar Panels Orbiter - Radios - Transponder -Camera -Laser mapping device -Solar Panels Lander -Transponder -Seismology detector -Radio -Solar Panels

Trade Tree Complete Lander MultipleSingle

Landing Systems Barbed Attachment Hooks Impactor Harpoon and Winch Skids Pyramid Design Cubic Design Trade Tree Gossamer Net

Mission Critical Components Tracking Architecture Transponder(s) on Lander(s) Transponder on Stand-off Vehicle Seismic Measurement Method Active Ping and Listen Passive Seismometer Trade Tree

System Description Orbiter with Landers –Rendezvous with Apophis –Landers deploy to Apophis – kg to Earth Orbit –~100 kg at Apophis

System Description Earth Operations –Launch –Start-up and system checkout Trajectory –Plane change and escape velocity burn –Orbit transfer burn and course corrections Initial Apophis Operations –Stand-off at safe distance –Initial imaging, mapping, data transfer –Landing site selection from Earth Apophis Close Approach and Deployment –Incremental Approach to Apophis –Hover above Apophis surface, deploy landers –Orbiter return to heliocentric orbit –Landers deploy, gather initial data and transfer Earth Close Approach Event –Tracking with transponders –Orbiter to Earth and Apophis attitudes –Shifting morphology seismometer readings –Data transfer to Earth Mission Profile

The Landing Problem Close approach of Apophis by orbiter Spring loaded deployment of landers Orbiter Apophis Surface

Lander Sub-systems and Instruments Step 1Step 2Step 3 Landers –Open Tetragon to automatically orient –Equipped with: 1)Shallow pitch drill 2)Acoustic equipment 3)Cross-link radio 4)Transponder 5)Solar panels

Orbiter Subsystems Orbiter Systems –Power: Solar Panels Stable, established source of energy No consumables Limited Degradation 1 kW requires ~7 m 2

Orbiter Subsystems Reaction Wheels –Minimum of 3 reaction wheel assemblies –Provide X,Y, & Z attitude control –Controlled from 1 control box Pulsed Plasma Thruster –Attitude control, low thrust maneuvers –Solid Propellants –High I sp, low impulse –Uses ionized, accelerated plasma 1.Energy Storage Unit 2.Ignitor 3.Fuel Rod 4.Plasma Accelerator

Orbiter Instruments Laser mapping device Transponder Star Tracker IMU, Gyros Radios –Crosslink with landers –Uplink –Downlink High bandwidth Low bandwidth Imagers –Near IR –Visual

Communication Link and Command & Data Handling Communication Link Uplink radio Downlink radio Cross-link Transponders Earth Command and Data Handling Solid state storage devices Semi-autonomous (command to begin programmed events) Ability to upload new command sets

Advantages: Landing System Redundancy: multiple landers can be deployed Landing orientation does not matter Hooks on all vertices discourage rebound off surface Robust landing structure to protect delicate equipment Spring loaded deployment results in low reaction force on orbiter Optical equipment remains on orbiter to avoid impact of landing

Advantages: Orbiter Subsystems Solar Panels –Proven technology –Stable energy source Semi-autonomous command –Allows for actions with limited communication –Flexibility Communications Link –Constant line of sight Imaging –B/W for low data rates –Near IR for composition data 3-Axis Control –Reaction Wheels Small, prebuilt assemblies No consumables –PPT Small form factor High I sp Low Impulse Tracking Scheme –Constant line of sight –Large power source –Simple transformations

Questions ?