GOES 12
Encyclopedia
GOES 12, known as GOES-M before becoming operational is an American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 weather satellite
Weather satellite
The weather satellite is a type of satellite that is primarily used to monitor the weather and climate of the Earth. Satellites can be either polar orbiting, seeing the same swath of the Earth every 12 hours, or geostationary, hovering over the same spot on Earth by orbiting over the equator while...

, which is part of the US National Oceanic and Atmospheric Administration's
National Oceanic and Atmospheric Administration
The National Oceanic and Atmospheric Administration , pronounced , like "noah", is a scientific agency within the United States Department of Commerce focused on the conditions of the oceans and the atmosphere...

 Geostationary Operational Environmental Satellite
Geostationary Operational Environmental Satellite
The Geostationary Satellite system, operated by the United States National Environmental Satellite, Data, and Information Service , supports weather forecasting, severe storm tracking, and meteorology research. Spacecraft and ground-based elements of the system work together to provide a continuous...

 system. It was launched in 2001, and it is in standby orbit. Prior to standby, it was operating in the GOES-EAST position, providing coverage of the east coast of the United States.

Launch

GOES-M was launched aboard an International Launch Services
International Launch Services
International Launch Services is a U.S.-Russian joint venture with exclusive rights to the worldwide sale of commercial Proton rocket launch services from the Baikonur Cosmodrome in Kazakhstan.- Ownership :...

 Atlas IIA
Atlas II
Atlas II was a member of the Atlas family of launch vehicles, which evolved from the successful Atlas missile program of the 1950s. Atlas II was the last Atlas to use a three engine, "stage-and-a-half" design: two of its three engines were jettisoned during ascent, but its fuel tanks and other...

 rocket, flying from Space Launch Complex 36A at the Cape Canaveral Air Force Station
Cape Canaveral Air Force Station
Cape Canaveral Air Force Station is an installation of the United States Air Force Space Command's 45th Space Wing, headquartered at nearby Patrick Air Force Base. Located on Cape Canaveral in the state of Florida, CCAFS is the primary launch head of America's Eastern Range with four launch pads...

. The launch occurred at 07:23 GMT on 23 July, having previously been delayed eight days; seven due to a faulty controller in the second stage
Centaur (rocket stage)
Centaur is a rocket stage designed for use as the upper stage of space launch vehicles. Centaur boosts its satellite payload to geosynchronous orbit or, in the case of an interplanetary space probe, to or near to escape velocity...

 of the carrier rocket, and one to ensure that a lightning strike at SLC-36B had not caused any damage to the rocket. At launch, the satellite had a mass of 2279 kilograms (5,024.3 lb), and an expected operational lifespan of five years, although it carried fuel for longer. It was built by Space Systems/Loral
Space Systems/Loral
Space Systems/Loral , of Palo Alto, California, is the wholly owned manufacturing subsidiary of Loral Space & Communications. It was acquired in 1990 for $715 million by Loral Corp. from Ford Motor Company as the Space Systems Division of Ford Aerospace...

, based on the LS-1300 satellite bus, and was the last of five GOES-I series satellites to be launched.

Operations

Following launch, it was positioned in geostationary orbit
Geostationary orbit
A geostationary orbit is a geosynchronous orbit directly above the Earth's equator , with a period equal to the Earth's rotational period and an orbital eccentricity of approximately zero. An object in a geostationary orbit appears motionless, at a fixed position in the sky, to ground observers...

 at a longitude
Longitude
Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, usually expressed in degrees, minutes and seconds, and denoted by the Greek letter lambda ....

 of 90° West, where it underwent on-orbit testing, and was then stored until it was needed to replace an operational satellite. It served as an on-orbit spare until 2003, when it was called up to replace GOES 8
GOES 8
GOES 8, known as GOES-I before becoming operational, was an American weather satellite, which formed part of the US National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellite system. It was launched in 1994, and operated until 2004 when it was retired and...

, an older satellite which, while still operational, would have run out of fuel by the end of the year. Although GOES 11 was the next backup in line for activation, GOES 12 was used instead in order to test its Solar X-ray Imager
Solar X-ray Imager
-Operation:The Solar X-ray Imager aboard the GOES 12, GOES 13, GOES 14, and GOES 15 United States NOAA weather satellites is used for early detection of solar flares, coronal mass ejections, and space phenomena that impact human spaceflight and military and commercial satellite communications...

. The Solar X-ray Imager failed in April 2006.

Thruster problems

Since December 2007, GOES 12 has experienced three thruster leaks during orbital adjustment manoeuvres, two of which led to major outages. The first of these occurred in December 2007, during an annual manoeuvre to reduce the inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...

 of the satellite's orbit. The faulty thruster was shut down, and the satellite was returned to its station by means of what was thought at the time to be a backup thruster. It was later discovered that the primary and backup thrusters had been wired the wrong way around, so it had actually switched from the backup system to the primary system, however this was believed to be unrelated to the failure. During this outage, GOES 10
GOES 10
GOES 10, known as GOES-K before becoming operational, was an American weather satellite, which formed part of the US National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellite system...

, a retired satellite which had been kept in orbit to provide coverage of South America, was briefly returned to service to cover for GOES 12.

Another outage occurred on 14 December 2008, when an inactive thruster leaked, sending the satellite out of control. The on-orbit-spare satellite, GOES 13
GOES 13
GOES 13, known as GOES-N before becoming operational, is an American weather satellite which is part of the US National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellite system. It was launched in 2006...

, was brought online in case GOES 12 had to be replaced, and took over imagery from its storage location at 105° West whilst the fault was investigated. The problem cleared several weeks later, and the satellite was returned to operational status on 5 January 2009, with GOES 13 being returned to on-orbit storage.

Since then, several other leaks have occurred, however none has impacted operations. During a leak in May 2009, the GOES 13 satellite was again activated, however it did not need to take over operations. Because of the thruster problems, GOES 12 was replaced by GOES 13 in the GOES-EAST position. GOES 12 continues to be operational, but in standby.
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