A predominant section of Celestial Mechanics is the satellite visualization. The image below was generated from the orbits of Low Orbiting Satellites of the Earth, based on data from SSR's (Satellite Situation Reports) collected from the public domain that date from 1994 to the present. Our viewpoint is as if we are standing on the surface of the earth, roughly around the Los Angeles area, looking skyward.
In order to generate the image, the data was parsed into MEL, a scripting language used by the 3D animation program Maya, which was then rendered into animation frames. The animation was then sped up to roughly 500x, so the viewer is exposed to the sheer scope of objects that are constantly in orbit. The average speed of an LEO satellite is 17,000 MPH, and the average size is between 1 and 2 meters across. Their functions vary from observation, to data collection, to communication, to military usage. The rings visible in this particular visualization are the satellites' line of site ring, which is the elliptical area of the Earth's surface that each satellite can "see". When each line of site ring is rendered, it is possible to see the scope of observation that is taking place.
Below is a still from an animation generated from data in SSR's from June to November, 2005, and a handful of interesting satellites that are currently above the earth. Even though they are among hundreds others, the short list of individual satellites shows you many unique functions. These satellites are chosen at random, they are listed only to illustrate variety
ORBVIEW 1 (MICROLAB), launched 04/03/1995
Description
Microlab 1 is a minisatellite that was launched by a Pegasus rocket carried aloft by an aircraft flying out of Vanderberg AFB. The main instrument is used to map global lightning and to infer the atmospheric temperature and humidity.
WESTPAC, launched 07/10/1998
Description
Westpac was an Australia geodetic satellite for the joint venture between Australia's Electro Optics and the Russian Space Agency. It was spherical in shape with laser reflectors. It served as a target for the Western Pacific Laser Tracking Network.
IRIDIUM 17, launched 07/09/1997
Description
Iridium 17 was part of a planned commercial communications network comprised of a constellation of 66 LEO spacecraft. The system provides global communications services through portable handsets. Number 17 is one of 125 spacecraft that were built by Lockheed for more than $700M. Commercial service began in 1998.
TRMM, launched 11/27/1997
Description
The Tropical Rainfall Measuring Mission (TRMM) is a joint mission between NASA and the Japan Aerospace Exploration Agency (JAXA) designed to monitor and study rainfall over the global tropics and subtropics.
UNISAT 2, launched 12/20/2002
Description
Unisat is a 12kg, Italian Picosat that was launched from Baikonur by a Dnepr rocket on the Dec/20/2002. It carries a camera and sensors for picking up debris and aerosol in the atmosphere.
NOAA 16 DEB, launched 09/21/2000
Description
NOAA 16 continues the fourth-generation of operational, polar orbiting, meteorological satellite series operated by the National Oceanic and Atmospheric Administration (NOAA). The goal is to provide data used in weather prediction and warning.
CHAMP, launched 07/15/2000
Description
CHAMP (CHAllenging Minisatellite Payload) is a German environmental research minispacecraft that carries instruments for collecting geophysical, oceanographic, and meteorological data.
HETE 2, launched 10/09/2000
Description
The High Energy Transient Explorer 2 (HETE-2) is designed to detect cosmic gamma-ray bursts (GRBs) and help determine their origin and nature. The goal of the mission is to continuously scan the sky and identify occurences of GRBs, establish precise locations and transmit coordinates in near real time. The spacecraft is basically a rectangular cube, roughly one meter by half a meter by half a meter, with four solar panel petals protruding from the bottom.
CUTE-1, launched 06/30/2003
Description
CUTE 1 is a Japanese (Tokyo Institute of Technology) one kilogram nanosatellite that was launched by a Rokot rocket from Plesetsk on 30 June 2003.
OSCAR 29, launched 09/16/1987
Description
OSCAR 29 was a US Navy navigation satellite launched by a Scout G rocket. Transit, one of the first operational satellite systems, was also known as the Navy Navigation Satellite (NNS). The Transit spacecraft were developed for updating thenavigation systems on board US Navy Polaris submarines, and later for civilian use. Transit was superseded by the Navstar global positioning system. The use of the satellites for navigation was discontinued at the end of 1996 but the satellites continued transmitting.
WIRE, launched 03/05/1999
Description
The Wide-field Infrared Explorer (WIRE) was a two-color, solid hydrogen-cooled, infrared imaging telescope designed to study starburst galaxies and to search for protogalaxies. Shortly after launch, while the spacecraft was still tumbling early after orbit insertion, the telescope cover came off prematurely. Attempts to recover control of the spacecraft were successful, though as a result of the coolant loss, science data was not obtainable.
MOS 1A (MOMO 1), launched 02/19/1987
Description
The Marine Observation Satellite (MOS-1) was Japan's first earth observation satellite. The spacecraft carried several technologies that collected data from both land and sea including sea surface temperature, information on sea ice, snowfall, and water vapor content at the ocean and in the atmosphere.
ROCSAT 2, launched 05/20/2004Description
Rocsat 2 is a Taiwanese (ROC) remote sensing satellite that carries imaging instruments to take pictures of crop yields in Taiwan, natural disasters, and oil spills on land and ocean, and to image high altitude red lightning strokes called sprites.
TRANSAT, launched 10/28/1977
Description
Transit-O 11 ois another part of the now defunct Transit Network that operated for 10 years and were superseded by the Navstar global positioning system. The use of the satellites for navigation was discontinued at the end of 1996 but the satellites continued transmitting and became the Navy Ionospheric Monitoring System (NIMS).
EO 1, launched 11/21/2000
Description
EO 1 (Earth Observing mission 1) is the first spacecraft in the American New Millennium Program (NMP) and carries three well-developed instruments (and seven technology-test items) to image Earth's surface in numerous wavelength bands. That data it provides is used to provide better crop estimates, better mineral resource areas, and water vapor and cirrus cloud variations.
MAROC TUBSAT, launched 12/10/2001
Description
Maroc-Tubsat is a Moroccan microsatellite that was launched by a Zenit rocket from Baikonur on Dec/10/2001. Its mission was to test a 3-dimensional attitude control system that will be incorperated in a future remote sensing mission.
COBE, launched 11/18/1989
Description
The purpose of the Cosmid Background Explorer (COBE) satellite mission was to take precise measurements of the diffuse radiation over the Earth. The instruments performed a complete scan of the celestial sphere every six months. Instrument operations were terminated in 1993, and the satellite has been converted into a test satellite.