Orbiting Carbon Observatory
Encyclopedia
The Orbiting Carbon Observatory (OCO) is a NASA
satellite mission intended to provide global space-based observations of atmospheric
carbon dioxide
(CO2). The original spacecraft was lost in a launch
failure on February 24, 2009, when the payload fairing
of the Taurus rocket which was carrying it failed to separate during ascent. The added mass of the fairing prevented the satellite from reaching orbit
. It subsequently re-entered the atmosphere
and crashed into the Indian Ocean
near Antarctica. The FY 2010 NASA budget request includes US$170 million for NASA to develop and fly a replacement for the Orbiting Carbon Observatory.
, the natural processes and human activities that influence the abundance and distribution of the greenhouse gas
. This improved understanding was expected to enable more reliable forecasts of future changes in the abundance and distribution of carbon dioxide in the atmosphere
and the effect that these changes may have on Earth
's climate
.
The OCO spacecraft was provided by Orbital Sciences Corporation
. It was launched from Vandenberg Air Force Base
in California on a dedicated Taurus XL rocket. However, the payload fairing — a clam shell-shaped covering that protects the satellite during launch — apparently failed to separate from the spacecraft. "We have not had a successful launch tonight and will not be able to have a successful OCO mission," NASA commentator George Diller said.
During its two-year mission, OCO would have flown in a near polar orbit
which would have enabled the instrument to observe most of Earth's surface at least once every sixteen days. It would have flown in loose formation with a series of other Earth-orbiting satellites known as the Earth Observing System Afternoon Constellation, or the A-train
. This coordinated flight formation was intended to enable researchers to correlate OCO data with data acquired by other instruments on other spacecraft. In particular, Earth scientists could have compared OCO data with nearly simultaneous measurements acquired by the Atmospheric Infrared Sounder
(AIRS) instrument, flying on NASA’s Aqua
satellite.
The cost of the mission was US$280 million. It was sponsored by NASA's Earth System Science Pathfinder Program. NASA’s Jet Propulsion Laboratory
in Pasadena, California
, manages OCO for NASA's Science Mission Directorate.
s, integrated into a common structure and fed by a common telescope
. The spectrometers would have made simultaneous measurements of the carbon dioxide and molecular oxygen absorption of sunlight reflected off the same location on Earth’s surface when viewed in the near-infrared
part of the electromagnetic spectrum
, invisible to the human eye.
As sunlight passes through Earth’s atmosphere and is reflected from Earth’s surface, molecules of atmospheric gases absorb very specific colors of light. If the light is divided into a rainbow of colors, called a spectrum
, the specific colors absorbed by each gas appear as dark lines. Different gases absorb different colors, so the pattern of absorption lines provides a telltale spectral “fingerprint” for that molecule. OCO’s spectrometers were designed to detect these molecular fingerprints.
Each of the three spectrometers was tuned to measure the absorption in a specific range of colors. Each of these ranges includes dozens of dark absorption lines produced by either carbon dioxide or molecular oxygen. The amount of light absorbed in each spectral line increases with the number of molecules along the optical path. OCO's spectrometers would have measured the fraction of the light absorbed in each of these lines with very high precision. This information was then to be analyzed to determine the number of molecules along the path between the top of the atmosphere and the surface.
If the amount of carbon dioxide varies from place to place, the amount of absorption will also vary. To resolve these variations, the observatory’s instrument was to record an image of the spectrum produced by each spectrometer three times every second as the satellite flies over the surface at more than four miles per second. This information would then have been transmitted to the ground, where carbon dioxide concentrations would have been retrieved in four separate footprints for each image collected. These spatially varying carbon dioxide concentration estimates would then have been analyzed using global transport models, like those used for weather prediction, to infer the locations of carbon dioxide sources and sinks.
The OCO instrument was developed by Hamilton Sundstrand
Sensor Systems in Pomona, California
, and the Jet Propulsion Laboratory
.
The OCO launch failed because the Taurus-XL launcher payload fairing failed to separate. A payload fairing is a clamshell-shaped cover that encloses and protects a payload on the pad and during early flight. Fairings are a standard component of expendable launch vehicles, and they are always jettisoned as soon as possible after a rocket has climbed high enough for heating from air friction to no longer risk damaging the payload. On this flight, the fairing should have been jettisoned several seconds after Stage 2 ignition. The extra mass of the fairing was not a significant factor during the flight of the larger lower stages, but it kept the relatively small Stage 3 from adding enough velocity to reach orbit, so the resulting sub-orbital ballistic path took the payload into the ocean near Antarctica, 17 minutes after liftoff.
The Orbital Taurus program manager John Brunschwyler said, "We could not make orbit. ... Initial indications are the vehicle did not have enough [force] to reach orbit and landed just short of Antarctica in the ocean. ... Certainly for the science community, it's a huge disappointment."
On July 17, 2009 NASA released a summary of its Mishap Investigation Board report. In the report the board provided recommendations to prevent any future problems associated with the four hardware components that could have caused the failure.
On June 23, 2010 NASA selected Orbital Sciences for OCO 2 to launch in February 2013 on a Taurus XL 3110 from Vandenberg Air Force Base in California.
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
satellite mission intended to provide global space-based observations of atmospheric
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...
carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
(CO2). The original spacecraft was lost in a launch
Rocket launch
A rocket launch is the takeoff phase of the flight of a rocket. Launches for orbital spaceflights, or launches into interplanetary space, are usually from a fixed location on the ground, but may also be from a floating platform such as the San Marco platform, or the Sea Launch launch...
failure on February 24, 2009, when the payload fairing
Payload fairing
Payload fairing is one of the main components of a launch vehicle. The fairing protects the payload during the ascent against the impact of the atmosphere . More recently, an additional function is to maintain the cleanroom environment for precision instruments.Outside the atmosphere the fairing is...
of the Taurus rocket which was carrying it failed to separate during ascent. The added mass of the fairing prevented the satellite from reaching orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
. It subsequently re-entered the atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
and crashed into the Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
near Antarctica. The FY 2010 NASA budget request includes US$170 million for NASA to develop and fly a replacement for the Orbiting Carbon Observatory.
Mission description
OCO's measurements would have been accurate enough to show for the first time the geographic distribution of carbon dioxide sources and sinks on a regional scale. The data would have improved the understanding of the global carbon cycleCarbon cycle
The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth...
, the natural processes and human activities that influence the abundance and distribution of the greenhouse gas
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...
. This improved understanding was expected to enable more reliable forecasts of future changes in the abundance and distribution of carbon dioxide in the atmosphere
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...
and the effect that these changes may have on Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
's climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
.
Orbital Sciences Corporation
Orbital Sciences Corporation is an American company which specializes in the manufacturing and launch of satellites. Its Launch Systems Group is heavily involved with missile defense launch systems...
. It was launched from Vandenberg Air Force Base
Vandenberg Air Force Base
Vandenberg Air Force Base is a United States Air Force Base, located approximately northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command ....
in California on a dedicated Taurus XL rocket. However, the payload fairing — a clam shell-shaped covering that protects the satellite during launch — apparently failed to separate from the spacecraft. "We have not had a successful launch tonight and will not be able to have a successful OCO mission," NASA commentator George Diller said.
During its two-year mission, OCO would have flown in a near polar orbit
Polar orbit
A polar orbit is an orbit in which a satellite passes above or nearly above both poles of the body being orbited on each revolution. It therefore has an inclination of 90 degrees to the equator...
which would have enabled the instrument to observe most of Earth's surface at least once every sixteen days. It would have flown in loose formation with a series of other Earth-orbiting satellites known as the Earth Observing System Afternoon Constellation, or the A-train
A-train (satellite constellation)
The A-train is a satellite constellation scheduled to have seven Franco-American Earth observation satellites in sun-synchronous orbit at an altitude of 690 kilometers above the Earth....
. This coordinated flight formation was intended to enable researchers to correlate OCO data with data acquired by other instruments on other spacecraft. In particular, Earth scientists could have compared OCO data with nearly simultaneous measurements acquired by the Atmospheric Infrared Sounder
Atmospheric Infrared Sounder
The Atmospheric Infrared Sounder is one of six instruments flying on board NASA’s Aqua satellite, launched on May 4, 2002. The instrument is designed to support climate research and improve weather forecasting....
(AIRS) instrument, flying on NASA’s Aqua
Aqua (satellite)
Aqua is a multi-national NASA scientific research satellite in orbit around the Earth, studying the precipitation, evaporation, and cycling of water. It is the second major component of the Earth Observing System preceded by Terra and followed by Aura .The name "Aqua" comes from the Latin word...
satellite.
The cost of the mission was US$280 million. It was sponsored by NASA's Earth System Science Pathfinder Program. NASA’s Jet Propulsion Laboratory
Jet Propulsion Laboratory
Jet Propulsion Laboratory is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is headquartered in the city of Pasadena on the border of La Cañada Flintridge and Pasadena...
in Pasadena, California
Pasadena, California
Pasadena is a city in Los Angeles County, California, United States. Although famous for hosting the annual Rose Bowl football game and Tournament of Roses Parade, Pasadena is the home to many scientific and cultural institutions, including the California Institute of Technology , the Jet...
, manages OCO for NASA's Science Mission Directorate.
Technology
The satellite carried a single instrument that would have taken the most precise measurements of atmospheric carbon dioxide ever made from space. The instrument consisted of three parallel, high-resolution spectrometerSpectrometer
A spectrometer is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's intensity but could also, for instance, be the polarization...
s, integrated into a common structure and fed by a common telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
. The spectrometers would have made simultaneous measurements of the carbon dioxide and molecular oxygen absorption of sunlight reflected off the same location on Earth’s surface when viewed in the near-infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
part of the electromagnetic spectrum
Electromagnetic spectrum
The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object....
, invisible to the human eye.
As sunlight passes through Earth’s atmosphere and is reflected from Earth’s surface, molecules of atmospheric gases absorb very specific colors of light. If the light is divided into a rainbow of colors, called a spectrum
Spectrum
A spectrum is a condition that is not limited to a specific set of values but can vary infinitely within a continuum. The word saw its first scientific use within the field of optics to describe the rainbow of colors in visible light when separated using a prism; it has since been applied by...
, the specific colors absorbed by each gas appear as dark lines. Different gases absorb different colors, so the pattern of absorption lines provides a telltale spectral “fingerprint” for that molecule. OCO’s spectrometers were designed to detect these molecular fingerprints.
Each of the three spectrometers was tuned to measure the absorption in a specific range of colors. Each of these ranges includes dozens of dark absorption lines produced by either carbon dioxide or molecular oxygen. The amount of light absorbed in each spectral line increases with the number of molecules along the optical path. OCO's spectrometers would have measured the fraction of the light absorbed in each of these lines with very high precision. This information was then to be analyzed to determine the number of molecules along the path between the top of the atmosphere and the surface.
If the amount of carbon dioxide varies from place to place, the amount of absorption will also vary. To resolve these variations, the observatory’s instrument was to record an image of the spectrum produced by each spectrometer three times every second as the satellite flies over the surface at more than four miles per second. This information would then have been transmitted to the ground, where carbon dioxide concentrations would have been retrieved in four separate footprints for each image collected. These spatially varying carbon dioxide concentration estimates would then have been analyzed using global transport models, like those used for weather prediction, to infer the locations of carbon dioxide sources and sinks.
The OCO instrument was developed by Hamilton Sundstrand
Hamilton Sundstrand
Hamilton Sundstrand, is a global corporation that manufactures and supports aerospace and industrial products for worldwide markets. It was formed from the merger of Hamilton Standard and Sundstrand Corporation in 1999. A subsidiary of United Technologies Corporation, HS is headquartered in Windsor...
Sensor Systems in Pomona, California
Pomona, California
-2010:The 2010 United States Census reported that Pomona had a population of 149,058, a slight decline from the 2000 census population. The population density was 6,491.2 people per square mile...
, and the Jet Propulsion Laboratory
Jet Propulsion Laboratory
Jet Propulsion Laboratory is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is headquartered in the city of Pasadena on the border of La Cañada Flintridge and Pasadena...
.
Launch data
- Source: NASA
- Date: February 24, 2009, 1:55 a.m. PST
- Launch Vehicle: Orbital Sciences Taurus XL
- Launch Site: Vandenberg Air Force BaseVandenberg Air Force BaseVandenberg Air Force Base is a United States Air Force Base, located approximately northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command ....
– Launch Pad SLC 576-EVandenberg AFB Launch Complex 576Launch Complex 576, also known as Area 576, is a group of rocket launch pads at Vandenberg Air Force Base. The pads at the complex were used from 1959 until 1971 to launch SM-65 Atlas missiles. The site was also known as Complex ABRES...
The OCO launch failed because the Taurus-XL launcher payload fairing failed to separate. A payload fairing is a clamshell-shaped cover that encloses and protects a payload on the pad and during early flight. Fairings are a standard component of expendable launch vehicles, and they are always jettisoned as soon as possible after a rocket has climbed high enough for heating from air friction to no longer risk damaging the payload. On this flight, the fairing should have been jettisoned several seconds after Stage 2 ignition. The extra mass of the fairing was not a significant factor during the flight of the larger lower stages, but it kept the relatively small Stage 3 from adding enough velocity to reach orbit, so the resulting sub-orbital ballistic path took the payload into the ocean near Antarctica, 17 minutes after liftoff.
The Orbital Taurus program manager John Brunschwyler said, "We could not make orbit. ... Initial indications are the vehicle did not have enough [force] to reach orbit and landed just short of Antarctica in the ocean. ... Certainly for the science community, it's a huge disappointment."
On July 17, 2009 NASA released a summary of its Mishap Investigation Board report. In the report the board provided recommendations to prevent any future problems associated with the four hardware components that could have caused the failure.
Proposed reflight
Three days after the failed February 2009 launch, the OCO science team sent NASA headquarters a proposal to build and launch an OCO "carbon copy", which planned to have the replacement satellite launched by late 2011. On February 1, 2010, the FY 2010 NASA budget request did include US$170 million for NASA to develop and fly a replacement for the Orbiting Carbon Observatory.On June 23, 2010 NASA selected Orbital Sciences for OCO 2 to launch in February 2013 on a Taurus XL 3110 from Vandenberg Air Force Base in California.
See also
- Greenhouse Gases Observing SatelliteGreenhouse Gases Observing SatelliteThe Greenhouse Gases Observing Satellite or GOSAT, also known as , is an Earth observation satellite and the world's first satellite dedicated to greenhouse-gas-monitoring, which will be used to measure densities of carbon dioxide and methane from 56,000 locations on the Earth's atmosphere...