The USA - Today and Tomorrow

Understanding the Earth

The prevailing view of NASA is mainly concen- trated around spectacular missions to the Interna- tional Space Station, to the moon and beyond etc., but NASA is much more. NASA also man- ages the world’s most advanced and most com- prehensive programmes for observations on. The "To fully understand the system on earth as well as the changing climate." organization operates This image, taken August 7, 2009 shows the typhoon Moracot threating Taiwan. The typhoon fifteen satellite missions dumped more than 2000 mm of rain over the island and caused the worst flooding in half a that produce close to 4 century. Photo: NOAA terabytes of data every day. Through these sat- NASA’s ambitious goal is to fully the rest are different research satellites. ellite sensors, NASA op- understand the system on earth as well as Ten of the in-orbit missions are conducted applying fourteen different international erates and controls the the changing climate, and in association with national and international partners partners. world’s largest scientific apply this understanding for the well- NASA’s Earth Observation data and information being of society. A key strategic element Programmes are divided in six different areas, Earth Science Research, Earth system for collecting, is sustained simultaneous observations to unravel the complexity of the global Systematic Missions, Earth System processing, archiving, integrated earth monitoring system. In Science Pathfinder, Earth Science Multi- and distributing earth addition to the fifteen operative satellites Mission Operations, Earth Science Technology and Applied Sciences system data to users NASA has today, five new missions are being defined, developed or, said in worldwide. another way; pre engineered. Two missions Earth Science Research are scheduled to be launched about late 2013 and early 2015, while the remaining The Science Mission Directorate three are in pre-formulation stages. issues the Research Opportunities in Space Seven in-orbit satellite missions and Earth Science (ROSES), a research provide data in near-real time to the announcement covering all of the planned National Oceanic and Atmospheric research solicitations in the Earth Science Administration (NOAA) for operational Research for the following years. Roughly forecasts of weather, hurricanes, air a third of the Earth Science Research quality, and harmful algal blooms, while

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budget is completed each year through defines requirements for scientific missions, which may include suborbital ROSES. The resulting grants are generally observations through the vantage point of payloads, instruments to be flown on non- funded for three years following the space. Each of Earth Science’s six focus NASA spacecrafts, or small dedicated selections. areas has an implementation roadmap that spacecrafts, will be selected via an On-going scientific research areas shows what role space-based observations announcement of opportunity. Selection on earth, including ocean circulation, are play in meeting overall science objectives. of the first Venture-class mission(s) is the effect of decreasing sea ice coverage The six Earth Science focus areas are as planned for 2010. on the climate, energy and water cycles, follows: Climate variability and change; arctic research of the composition of the Atmospheric composition; Carbon cycle, Earth Science Multi- troposphere, geodetic imaging, global ecosystems, and biogeochemistry; Water modelling of the earth system, hurricane and energy cycles; Weather; and Earth Mission Operations science and biodiversity. surface and interior. This effort also In this respect, NASA has already provides techniques and technologies The Earth Science Multi-Mission initiated a new Airborne Science that can be employed to predict climate, Operations Program will continue the Campaign, called IceBridge, to “bridge weather and natural hazards on planets operation of the “Earth Observing System the gap” between ICESat I and ICESat II they plan to explore. Data and Information System” (EOSDIS). data. This activity, focusing on changes in The maintenance of these systems is important to the collection of data from Greenland and the Arctic ice, will continue Earth System Science in 2010 and beyond. Earth Science satellites in orbit, as well as Pathfinder to the continuity of Earth Science research efforts. Earth Systematic In these programmes NASA seeks Missions answers to some of the basic questions connected to general Earth Science. The Earth Science Technology mission closest to its launch in 2010 is the To fulfil the goals identified in the The Earth Science Technology Aquarius/SAC-D observatory. report, “Earth Science and Applications Program (ESTP) will develop new Aquarius is a focused satellite mission from Space: National Imperatives for remote-sensing and information designed to measure global Sea Surface the Next Decade and Beyond”, the Soil system technologies for infusion into Salinity. After its launch, it will provide the Moisture Active-Passive (SMAP) and future scientific missions to enable, or global view of salinity variability needed Ice, Cloud, and Land Elevation Satellite dramatically enhance, measurements and for climate studies. The Aquarius / SAC-D (ICESat II) missions will be pursued data system capabilities, a programme in mission is being developed by NASA and aggressively, leading to projected launches order to further develop and manage the the Space Agency of Argentina. between late 2013/early 2015. Studies of large amount of data from the different NASA is also working on how best to two new missions, the Climate Absolute types of earth observation data. Radiance and Refractivity Observatory meet the lost scientific contributions after (CLARREO) and the Deformation, the Orbiting Carbon Observatory (OCO) Ecosystem Structure, and Dynamics of Ice launch vehicle failure earlier this year. Applied Science (DESDynI), will also be intensified. Studies are carried out to examine both The Applied Sciences Program will The Earth Systematic Missions (ESM) science and hardware considerations. The continue to work across the range of Programme provides a number of earth- scientific study is assessing the current application areas, especially focusing on observing satellites that contribute to the state of carbon cycle science and existing supporting communities as they plan for provision of long-term environmental measurements to see what course of action and respond to the impacts of climate data sets that can be used to study the would best address the key scientific change. Its ultimate aim is to incorporate evolution of the earth system on a range issues. With regard to the hardware, NASA earth science data into decision making of temporal scales. NASA works with the is examining re-flight opportunities, activities for policy and management. The science community to identify scientific including, but not limited to, flying an Applied Sciences Programme used this questions on the frontiers of science that OCO-like instrument on a shared platform study to identify the best practices and have profound societal importance, and or as a dedicated mission. to benchmark its approaches on strategic to which on-going remote sensing of the In response to the report, “Earth planning, implementation, partnership earth can make a defining contribution. Science and Applications from Space”, development, and administration. These scientific questions become the NASA is initiating a new series of foundation of a research strategy, which competed “Venture-class” missions. These

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OCO- A Mission Not Accomplished

The Orbiting Carbon Observa- tory (OCO), a satellite one had high expectations to, unsuccessfully launched and was totally lost early this year. Its main mission was to detect the current state of the carbon cycle in the atmosphere. The loss of the satellite was an enormous setback for the research activities connected to the carbon cycle and NASA is now examining different re-flight opportu- nities.

The A-train Constellation

An example of both the American involvement and the international col- Incessant delays and cost laboration is the satellite constellation; the so-called A-train, five different satel- lites placed in close proximity in orbit that pass the same point of earth with short overruns for a NPOESS-sensor intervals. The afternoon A-train consists of the following satellites; NASA’s Aqua, Aura, CALIPSO, Cloudsat and the French PARASOL. The OCO satellite, recently lost Another problem is the next in an unsuccessful launch, should have been the sixth in the train. NASA’s Glory generation operational polar orbiting will also join the constellation when the satellite is to be launched. satellites, NPOESS. One of the sen- Each satellite within the A-Train has unique measurement capabilities that sors for this satellite, Visible/Infrared greatly complement each other. For the first time, near simultaneous measure- Imaging Radiometer Suite is slated ments of aerosols, clouds, temperature, relative humidity, and radiative fluxes to fly on the two first new NPOESS (the change of radiation in a layer) will be obtained across the globe during all satellites, as well as the NPOESS Pre- seasons. This ensemble of observations will allow one to understand how large paratory Project (NPP). The Visible/ scale aerosol and cloud properties change in response to changing environmental Infrared Imaging Radiometer Suite, conditions. It will further allow one to determine how changing cloud and aerosols designed to monitor cloud formations distributions influence our climate with greater clarity than possible before. and other atmospheric and ocean-sur- For much of its life, the A-Train will be maintained in orbit within 15 minutes face phenomena has been a constant of the leading and trailing spacecraft while traveling over 15,000 miles per hour. problem for NOPESS and has con- CloudSat and CALIPSO will be controlled to an even finer requirement, within 15 tributed to restructuring of the whole seconds of each other, so that both instrument suites will view the same cloud project, steady delays of the satellite area almost simultaneously. This capability is crucial for studying clouds, most of and large cost overruns. NPP was which have a lifespan of less than 15 minutes. planned for launch in 2010 but is now The constellation has a nominal orbital altitude of 705 km and inclination slated to launch in January 2011 and of 98 degrees. Aqua will lead the constellation with an equatorial crossing time the first NPOESS will not be launched of about 1:30 PM. CloudSat and CALIPSO lag Aqua by 1 to 2 minutes and will be until May 2014. separated from each other by 10 to 15 seconds. The constant delays and cost The satellites in the A-Train are maintained in orbit to match the World overruns have raised questions about Reference System 2 (WRS-2) reference grid. This reference system was developed the managing of the project further- to facilitate regular sampling patterns by remote sensors in the Landsat program. more, it has raised questions about Each satellite completes 14.55 orbits per day with a separation of 24.7 degrees whether one should completely res- longitude between each successive orbit at the equator. The orbit tracks westward ructure the project management. 10.8 degrees on succeeding days, which over a 16-day period produces a uniform WRS grid over the globe. The WRS grid pattern consists of 233 orbits with separa- For more information, see tion between orbits at the equator of 172 km. http://science.hq.nasa.gov/missions/ earth.html.

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