Space Systems

Pg 1 of 44AGI www.agiuc.com

Space SystemsBob Hall & John Carrico


Agenda

• Background• Examples• How AGI technology is applied to space• When AGI technology is applied to space


Background

• STK, ODTK, NTK: “Tool Kit”– Many small tools that used together can model large

complex systems

• Models of how things move• Models of moving payloads on moving things

– Sensors– Antennas

• Models of how these moving things interact


Background…

• Space Applications– Defense

• Air Force and other DoD• UK MOD• French Air Force

– Civil• NASA• ESA• CNES • DLR• JAXA• NSPO

– Commercial and Contractors• Digital Globe, Space Imaging, OrbImage, Sirius, XM• Boeing, Lockheed Martin, Northrop Grumman, Orbital Sciences • Qinetiq, SSTL • EADS Astrium• RSC Energia


Examples

• 1 spacecraft• 2 spacecraft• Many spacecraft


Imaging satellite

• When can I take a picture of a target?– Constraints– Lighting– Terrain


Communications

• When can I communicate with my satellite?– Constraints– Signal-to-noise; Bit error rate– Terrain– Interference and jamming

Jammed Beam


Attitude

• Model attitude control laws– Sensors– Actuators


Solar power

• Calculate power based on solar array geometry relative to Sun


Sensor obscuration

• Parts of spacecraft block sensor field-of-view


Ground-track control

• Repeating-ground-track Sun-synchronous frozen- orbit


Transfer to geostationary• Normal transfer

– Sensor constraints– Where to put sensors

• Sun sensor– Maneuvers– Launch window

• Delta-V vs Sun angle


Transfer to geostationary…

• AsiaSat3 rescue

• Low-thrust


Geostationary

• Orbit

• Communications– Multi-beam and shaped patterns


Lunar transfer


Lunar landing• Landing site selection

– Communications– Lighting– Terrain

• Soft landing• Closed loop control


Libration point

• Sun-Earth/Moon• Gravity assist


Libration point…• Earth-Moon

– Communications relay

– Station/depot– Transfer


Libration point…

• Any set of bodies


Interplanetary• Communications, coverage,

attitude, orbits, maneuvers work around other planets

• Aerobraking• Make your own asteroids


Multiple hop communications

• Chains


ODTK

• Tracking spacecraft and calculating the orbit• Operations

– Automation– Notification


Error Analysis

– Tracking schedule to meet requirements

• With STK

– What types of tracking do I need

• Is it worth it to add additional hardware?

– What if we miss a pass?


ODTK…

• Maneuver detection

• Maneuver and OD

• Maneuver calibration


Rendezvous• Rendezvous: often used to describe getting a spacecraft from one orbit to a control

box near but offset from another– Rendezvous from 6678 km sma orbit to 6838 km sma orbit– 4 maneuvers used to execute 2 Hohmann transfers

• Proximity Operations: Begins after rendezvous– Very near another spacecraft (e.g., < 1 km)

• Docking: Controlling spacecraft to touch at desired velocity


Docking

• Closed loop control

• Fuzzy logic controller used for multiple constraints


Proximity Operations• Moving one spacecraft

around and close to another• Multiple way-points and

collection stay-times


Formation flying• Formation design

• Communications

• Science and sensor collection


Constellations

• Coordinated mission– Sensors– Communications

• Constellation design

• Relative station keeping


Space and other objects• Interaction with missiles, ground,

sea, and air• Same capabilities work

communications, navigation, sensor collection


Close approach• Conjunction analysis

• Launch windows

• Laser clearinghouse


Coverage• Single object

• Area– Constraints– Interference– Terrain

• Attitude

• Works on the Moon and Mars


GPS

• NTK• Ground• Aircraft• Spacecraft


Scheduling

Tasks

Resources

Timeslots

ScheduledActivity

ResourceAvailability


STK/Analyzer• Parametric analysis• Monte Carlo• Runs STK for you


How technology is applied

• Desktop• Automated desktop

– Matlab,– Excel

• Real-time situational awareness• Server on a network• Embedded system


Desktop

• Interactive• From quick trade-

off studies to high-fidelity analysis

• Reports and graphs


Automated desktop

• Use, Matlab, Excel, or other programs to run software for you


Real-time situational awareness

• Telemetry monitoring

• Other feeds– Flight Control


Live server on a network• LAN

• HTML

• Web Services


Data served on a network

• Pre-computed data

• Ground tracks

• Sensor footprints


Embedded system

• STKx• 4DX


When technology is applied

• Proposals• Early analysis• System design• Pre-launch analysis• Operations• Payload support• Contingency operations• Post-mission


Summary

• Many tools used in different ways applied to many situations

• Many examples of AGI Technology applied to space – more to come

• Designed for complete life-cycle

Space Systems

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