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| Credit : NASA Headquarters |
1). TOPEX/Poseidon
Launched in 1992, TOPEX/Poseidon is a joint venture between CNES and NASA that measured ocean surface topography to an accuracy of 4.2 cm, enabled scientists to forecast the 1997-1998 El Niño, and improved understanding of ocean circulation and its effect of global climate. While a 3-year prime mission was planned, with a 5-year store of expendables, TOPEX/Poseidon delivered an astonishing 13+ years of data from orbit. The mission ended in January 2006. In those 13 years, it:
1. Measured sea levels with unprecedented accuracy to better than 5 cm
2. Continuously observed global ocean topography
3. Monitored effects of currents on global climate change and produced the first global views of seasonal changes of currents
4. Monitored large-scale ocean features like Rossby and Kelvin waves and studied such
5. phenomena as El Niño, La Niña, and the Pacific Decadal OscillationMapped basin-wide current variations and provided global data to validate models of ocean circulation
6. Mapped year-to-year changes in heat stored in the upper ocean
7. Produced the most accurate global maps of tides everImproved our knowledge of Earth's gravity field
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| Credit : NASA |
2). TERRA
Fifteen year ago (as of 2014) on December 18th, 1999, Terra was launched and started to see Earth for the first time. As the Flagship Earth Observing Satellite, Terra was the first satellite to look at Earth system science, collecting multiple types of data dedicated to various areas of Earth science. It joined other satellites designed to monitor specific areas of Earth science and has since been joined by others that all work in concert to collect data that leads to a better understanding of how our planet functions as a whole.
Since Terra’s launch, scientists are able to document relationships between Earth’s systems and examine their connections. Through every pass that Terra makes and every piece of data it and the other Earth Observing Satellites collect, the picture of our earth gets richer, revealing trends and connections for the entire earth, impacting all of Earth’s inhabitants.
Terra’s original design life was 6 years, after 15 years in orbit, Terra has been collecting valuable data about our planet for two and a half times its planned lifetime. This is due in no small part to the dedicated scientists and engineers who built, launched, and continue to maintain this valuable spacecraft that has surpassed its original mission objectives and continues to make outstanding contributions to Earth science.
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Credit : NASA
TERRA Satellite |
3). LAGEOS
LAser GEOdynamics Satellite-1 (LAGEOS) was designed by NASA and launched in 1976. It was the first spacecraft dedicated exclusively to high-precision laser ranging and provided the first opportunity to acquire laser-ranging data that were not degraded by errors originating in the satellite orbit or satellite array. LAGEOS-2, based on the LAGEOS-1 design, was built by the Italian Space Agency and was launched in 1992.
There are plans for the launch of LAGEOS-3, which is a joint multinational program with collaboration from France, Germany, Great Britain, Italy, Spain and the United States. Data from LAGEOS-3 would be used to measure, for the first time, a quasi-stationary property of the Earth - its gravitational magnetic dipole moment as predicted by Einstein's theory of general relativity.
The LAGEOS satellites are covered with 426 cube corner reflectors with all but four of these reflectors made with fused silica glass. The other four reflectors are made of germanium to obtain measurements in the infrared for experimental studies of reflectivity and satellite orientation.
Dr. Carl Sagan designed a plaque that was installed in LAGEOS-1. The plaque is 4 inches by 7 inches (10 cm by 18 cm) stainless steel plate. The spacecraft carries two identical copies included in its interior. In its upper center it displays the simplest counting scheme, binary arithmetic. The numbers one to ten in binary notation are shown. At upper right is a schematic drawing of the Earth in orbit around the Sun, and an arrow indicating direction of motion. The arrowhead points to the right, the convention adopted for indicating the future. All arrows accompanying numbers are "arrows of time". Under the Earth's orbit is the binary number one, denoting the period of time used on the plaque -- one revolution of the Earth, or one year. The remainder of the LAGEOS plaque consists of three maps of the Earth's surface. The first map denotes the Earth 268 million years in the past. All the continents are shown together in one mass. The close fit of South America into West Africa was one of the first hints that continental drift actually occurs. The middle map represents the zero point in time for the other two maps. It displays the present configuration of the planet. The final map shows the Earth's surface 8.4 million years from now -- very roughly the estimated lifetime of the LAGEOS. Many important changes in the Earth's surface are shown, including the drift of California out into the Pacific Ocean. Whoever comes upon the LAGEOS plaque needs only compare a current map of the Earth's geography with that in the lower two maps to calculate roughly the difference between his time and ours. Drift rates of about an inch per year can, in fact be estimated by comparing the bottom two maps. The same objective of LAGEOS and the method of telling time on the plaque are identical. (from NASA/John R. Bannister, February 1977 NASA Aerospace Education Services Project Oklahoma State University, Stillwater, Oklahoma).
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| Credit : NASA |
4). DISCOVER-AQ
DISCOVER-AQ, a NASA Earth Venture program funded mission, stands for Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality.
Near-surface pollution is one of the most challenging problems for Earth observations from space. However, with an improved ability to monitor pollution from satellites from DISCOVER-AQ, scientists could make better air quality forecasts, more accurately determine the sources of pollutants in the air and more closely determine the fluctuations in emissions levels. In short, the more accurate data scientists have at hand, the better society is able to deal effectively with lingering pollution problems.
The main objectives of the mission is to make several important observations such as :
1. Relate column observations to surface conditions for aerosols and key trace gases O3, NO2, and CH2O. Researchers will ask, How well do column and surface observations correlate?; What additional variables (e.g., boundary layer depth, humidity, surface type) appear to influence these correlations?; and On what spatial scale is information about these variables needed (e.g., 5 km, 10 km, 100 km) to interpret column measurements?
2. Characterize differences in diurnal variation of surface and column observations for key trace gases and aerosols. Researchers will ask, How do column and surface observations differ in their diurnal variation?; How do emissions, boundary layer mixing, synoptic transport, and chemistry interact to affect these differences?; and Do column and surface conditions tend to correlate better for certain times of day?
3. Examine horizontal scales of variability affecting satellites and model calculations. Researchers will ask, How do different meteorological and chemical conditions cause variation in the spatial scales for urban plumes?; What are typical gradients in key variables at scales finer than current satellite and model resolutions?; and How do these fine-scale gradients influence model calculations and assimilation of satellite observations?
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Credit : NASA
Titled "From pole to pole NASA Flying Laboratories Study our World " |
5). FUSE
The Far Ultraviolet Spectroscopic Explorer (FUSE) was a NASA astrophysics satellite/telescope whose purpose was to explore the Universe using the technique of high-resolution spectroscopy in the far-ultraviolet spectral region. The Johns Hopkins University (JHU) had the lead role in developing the mission, in collaboration with The University of Colorado at Boulder, The University of California at Berkeley, international partners the Canadian Space Agency (CSA) and the French Space Agency (CNES), and numerous corporate partners. Professor Warren Moos of the Henry A. Rowland Department of Physics and Astronomy at JHU was the Principal Investigator.
The FUSE satellite was launched on June 24, 1999, and operated until October 18, 2007. The mission was operated by a group of scientists and engineers from a control center in the Bloomberg Center for Physics and Astronomy building on JHU's Homewood campus in Baltimore, Maryland. The primary FUSE ground station was located at the Unversity of Puerto Rico Mayaguez. NASA/Goddard Space Flight Center provided management oversight of the project. As of 2014, FUSE was still the largest and most complex astrophysics mission that had been operated out of a university setting.
Over the years, hundreds of astronomers from all over the world used
FUSE to observe nearly 3000 different astronomical objects, totaling over 64 million seconds of successful observing time.
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| Credit : NASA |
6). MESSENGER
MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging), was a NASA robotic spacecraft that orbited Mercury between 2011 and 2015. The spacecraft was launched aboard a Delta II rocket in August 2004 to study Mercury's chemical composition, geology, and magnetic field.
Messenger started collecting its data for the mission on April 4, 2011 While its primary mission was completed on March 17, 2012, having collected close to 100,000 images. MESSENGER had achieved successful results from mapping of Mercury on March 6, 2013, and completed its first year-long extended mission on March 17, 2013. MESSENGER's second extended mission lasted for over two years, but as its low orbit degraded, it required thrust to avoid impact. It conducted its final reboost thrust on October 24, 2014, and January 21, 2015, before crashing into Mercury on April 30, 2015.
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| Credit : NASA |
7). NEEMO
NEEMO, the NASA Extreme Environment Mission Operations project - is a NASA analog mission that sends groups of astronauts, engineers and scientists to live in Aquarius, the world's only undersea research station, for up to three weeks at a time. Operated by Florida International University (FIU), Aquarius is located 5.6 kilometers (3.5 miles) off Key Largo in the Florida Keys National Marine Sanctuary. It is deployed next to deep coral reefs 62 feet (19 meters) below the surface.
The Aquarius habitat and its surroundings provide a convincing analog for space exploration. Much like space, the undersea world is a hostile, alien place for humans to live. NEEMO crew members, known as aquanauts, experience some of the same challenges there that they would on a distant asteroid, planet or moon. During NEEMO missions, the aquanauts are able to simulate living on a spacecraft and test spacewalk techniques for future space missions. Working in space and underwater environments requires extensive planning and sophisticated equipment. The underwater condition has the additional benefit of allowing NASA to "weight" the aquanauts to simulate different gravity environments.
A technique known as saturation diving allows the aquanauts to live and work underwater for days or weeks at a time. After twenty four hours underwater at any depth, the human body becomes saturated with dissolved gas. With saturation diving, divers can accurately predict exactly how much time they need to decompress before returning to the surface. This information limits the risk of decompression sickness. By living in the Aquarius habitat and working at the same depth on the ocean floor, NEEMO crews are able to remain underwater for the duration of their mission.
NASA is developing the technologies and systems to transport future explorers to multiple destinations, each with its own unique - and extreme - space environment. Future destinations may include near-Earth asteroids, the moon, and Mars and its moons. To prepare for these complex missions, NASA must conduct field tests in Earth-based extreme environments to plan, test and develop technologies that will help guide the future direction of human exploration of the solar system.
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Credit : NASA
Underwater NEEMO missions. |
This Article was written by : Anubhav Srivastava
Credits : All the above information published above is for information purpose only. All the credit for providing above information and images goes to
NASA.
YOU CAN READ ABOUT THESE MISSIONS ON NASA OFFICIAL MISSION WEBSITES.
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