Weather satellites were able to indicate the trend of climate change.

While there were wide needs for accurate navigation in military and civilian sectors, almost none of those were seen as justification for the billions of dollars it would cost in research, development, deployment, and operation for a constellation of navigation satellites.

On 21 October 2011 the first two of four operational satellites were launched to validate the system.

The first four operational satellites for navigation were launched in 2011 and once this In-Orbit Validation ( IOV ) phase was has been completed, additional satellites will be launched.

The first two Galileo In-Orbit Validation satellites were launched by Soyuz ST-B flown from Guiana Space Centre on October 21, 2011.

The first two satellites were launched on 21 October 2011 from Guiana Space Centre using a Soyuz launcher.

Those 4 IOV Galileo satellites were constructed by Astrium GmbH and Thales Alenia Space.

In February 2012 eight additional satellites were ordered, bringing the total to 22 FOC satellites.

Space probes have been placed into orbit around all the five planets known to the ancients: first Mars ( Mariner 9, 1971 ), then Venus ( Venera 9, 1975 ; but landings on Venus and atmospheric probes were performed even earlier ), Jupiter ( Galileo, 1995 ), Saturn ( Cassini / Huygens, 2004 ), and most recently Mercury ( MESSENGER, March 2011 ), and have returned data about these bodies and their natural satellites.

Operational satellites for television use were launched between 1984 and 1990.

When the first scientific satellites were launched in the first half of 1958 — Explorers 1 and 3 by the US, Sputnik 3 by the Soviet Union — they observed an intense ( and unexpected ) radiation belt around Earth, held by its magnetic field.

One of the leading VSAT service providers is Syscomptech, they were voted the best Direct VSAT Marketers in 2008 and maintains satellites with direct footprints over Nigeria.

In mid-1987 both satellites were still functioning.

The Daily Telegraph on 1 May 2008 reported that tunnels were being built into hillsides which could be capable of hiding up to 20 nuclear submarines from spy satellites.

Early satellites were each constructed as a unique " one-off " designs.

Late in the 20th century, cross-country microwave radio relays were replaced by fixed-service satellites.

Searches for satellites of Eros took place on January 28, and 4 and 9 February, none were found.

This is another proposed use of beam-powered propulsion, used on objects that were not designed to be propelled by it, for example small pieces of scrap knocked off (" spalled ") satellites.

NII was to have included more than just the physical facilities ( more than the cameras, scanners, keyboards, telephones, fax machines, computers, switches, compact disks, video and audio tape, cable, wire, satellites, optical fiber transmission lines, microwave nets, switches, televisions, monitors, and printers ) used to transmit, store, process, and display voice, data, and images ; it was also to encompass a wide range of interactive functions, user-tailored services, and multimedia databases that were interconnected in a technology-neutral manner that will favor no one industry over any other.

As used for Central and Eastern European countries it implies that the countries in question were " satellites " under the hegemony of the Soviet Union.

However, communications satellites have not been thought of, and TV broadcasts are still limited to line-of-sight, as they were at the time of writing.

In 1764, Charles Bonnet said in his Contemplation de la Nature that, " We know seventeen planets that enter into the composition of our solar system is, major planets and their satellites ; but we are not sure that there are no more.

Kate Martin, of the Center For National Security Studies said of the use of military spy satellites being used to monitor the activities of U. S. citizens: " They are laying the bricks one at a time for a police state.

" Reason and religion teach us, she said, that " we too are primary existences ... not the satellites of men.

General William L. Shelton has said that in order to protect against attacks, Space Situational Awareness is much more important than additional hardening or armoring of satellites.

When visible GPS satellites are close together in the sky, the geometry is said to be weak and the DOP value is high ; when far apart, the geometry is strong and the DOP value is low.

Minow said his greatest contribution was persuading Congress to pass legislation clearing the way for communications satellites.

" Further, Hindle said that such platforms flying in the stratosphere, as opposed to actual satellites, can achieve much higher levels of frequency use.

DRDO officials further said: " The American satellites that run the GPS had been switched off on the day Barack Obama was sworn in as United States President.

In its press release, the company said that " HTSE draws its design inspiration from the most complex self-energising bodies built by mankind — space stations, satellites and spaceships.

These peoples, desperately hoping to lift themselves to decent levels of living must not, by our neglect, be forced to seek help from, and finally become virtual satellites of, those who proclaim their hostility to freedom.

No more startling contrast to a system of sullen satellites could be imagined.

* 1991 – A rare tropical storm develops in the South Atlantic Ocean near Angola ; the first to be documented by satellites.

Because centrifugal force increases according to the square of, one would expect gravity to be cancelled for an object travelling 17 times faster than the Earth's rotation, and in fact satellites in low orbit at the equator complete 17 full orbits in one day.

Such a " sphere " would be a system of orbiting solar power satellites meant to completely encompass a star and capture most or all of its energy output.

Deployment of spacecraft and satellites using photovoltaics might be seen as the first small steps towards building a Dyson swarm ( see below for differences between these sub-types ).

Many dwarf galaxies may orbit a single larger galaxy ; the Milky Way has at least a dozen such satellites, with an estimated 300 – 500 yet to be discovered.

The known points used for point positioning can be triangulation points of a higher order network, or GPS satellites.

Once this In-Orbit Validation ( IOV ) phase has been completed, additional satellites will be launched to reach Initial Operational Capability ( IOC ) around mid-decade.

Competition winners from the remaining 25 Member States will name the satellites which will be launched until 2019.

The required satellites ( the planned number is 30 ) will be launched throughout the period 2011 – 2014 and the system will be up and running and under civilian control from 2019.

As of March 2010 it was verified that the budget for Galileo would only be available to provide the 4 IOV and 14 FOC satellites by 2014, with no funds currently committed to bring the constellation above this 60 % capacity.

An additional € 1. 9 billion was planned to be spent bringing the system up to the full complement of 30 satellites ( 27 operational + 3 active spares ).

Though Selective Availability capability still exists, on 19 September 2007 the US Department of Defense announced that newer GPS satellites would not be capable of implementing Selective Availability ;

As old satellites are replaced in the GPS Block IIIA program, SA will cease to be an option.

The GIOVE Mission segment operated by European Satellite Navigation Industries is exploiting the GIOVE-A / B satellites to provide experimental results based on real data to be used for risk mitigation for the IOV satellites that will follow on from the testbeds.

These testbed satellites will be followed by four IOV Galileo satellites that will be much closer to the final Galileo satellite design.