Satellites How do they work NAVSTAR Global Positioning

Satellites How do they work? NAVSTAR Global Positioning System Satellite

Uses Direct. TV, DBS News Telephones Cable GPS Emergency radio beacons

Components ANY object that revolves around a planet (e. g. the moon) Artificial Orbit, Apogee, and Perigee Custom built “Space junk”

Sputnik 1 (October 4, 1957) Soviet Union n n A Thermometer A Battery A Radio transmitter Pressurized Nitrogen gas

3, 2, 1, Lift-off (Launch) Rockets and the space shuttle Orbital Velocity and Altitude Launch Window

Types Weather satellites (TIROS, COSMOS) Communications satellites (Telstar, Intelsat) n transponder Broadcast satellites Scientific satellites (Hubble telescope) Navigational satellites (GPS Navstar) Rescue satellites Earth observation satellites (LANDST) Military satellites (? ? ? )

Components Frame/Body (Bus) Power source Computer Communications Attitude control system (ACS)

Geostationary Orbits Positioned over the same area Normally, 223 Miles Weather Communications Satellite

Asynchronous Orbits Multiple passes 80 -1, 200 miles n Teledesic, LEOs Observation (300600 miles) 3, 000 -6, 000 miles n Scientific 6, 000 -12, 000 miles n Navigation (GPS)

Polar Orbit Low altitude Passes over the poles on each orbit Mapping and photography

Teledesic: Low Earth Orbit Satellites (LEOs) Network of Constellations “Internet-inthe-Sky. TM”

LEO Coverage 288 operational satellites, divided into 12 planes with 24 satellites each

LEO Service Optical Inter-Satellite Links Intense coverage

Next Generation (Northpoint) Northpoint Technology Terrestrial satellite

Northpoint Current: n Multiple towers Northpoint n “cellular network”

Northpoint Impact Competition with cable and DBS Fiber optics to all Opportunities for Geostationary satellites Spectrum planning

Broadwave USA Inc. Local service Local and National Programming Cheaper