ESE Mission Programs
ESE’s research and applications requirements for Earth observation are met through a slate of systematic, exploratory and technology demonstration/operational precursor satellite programs, and a diversified suborbital science program of aircraft and balloons. Systematic measurement missions are those that supply long-term data records to determine variability and trends in parameters of known importance, such as atmospheric temperature, humidity and vegetation cover. The more mature measurements become candidates for transition to operational systems, such as NOAA’s meteorological satellites (which are currently built and launched by NASA). Exploratory measurement missions are those designed to probe poorly understood Earth system processes, such as the 3-D profile of aerosols in the atmosphere or the Earth’s gravity field. Once these processes are understood, and their change over time is found to be important, they become candidates for future systematic measurement missions. Technology demonstration/operational precursor missions are intended to reduce the cost of today’s measurements or make possible those of tomorrow. From 1999 through 2001, ESE launched 11 successful missions, with 12 more planned through 2004.

The Earth Observing System (EOS) was created primarily to meet the need for systematic measurements, and is the largest component of the ESE. It aims to carry NASA’s legacy of focused Earth Science measurements into a new era of comprehensive data sets, leading to an improved understanding of the Earth as a complete global system. EOS is managed by the Goddard Space Flight Center, with important contributions from other NASA centers: Jet Propulsion Laboratory, Langley Research Center, Marshall Space Flight Center, Wallops Flight Facility, and Stennis Space Center. In addition, NASA works in conjunction with many other partners from government, industry, academia, and with international space agencies.

This drawing depicts the Terra spacecraft in orbit. Terra is the flagship of the EOS Program and the instruments on board provide a wealth of new knowledge about the Earth System. The Aqua and Aura spacecraft are of similar design.

Twelve missions are planned as part of the EOS program and already NASA has launched six EOS spacecraft. These include the Quik Scatterometer (QuikScat), the Active Cavity Radiometer Irradiance Monitor Satellite (ACRIMSAT), the third Stratospheric Aerosol and Gas Experiment (SAGE III - Meteor 3M), Landsat 7, Jason-1, Terra and Aqua. Terra launched in December 1999 and is the flagship of the EOS program. It is a joint mission with Japan and Canada that carried five advanced instruments into orbit to study land and ocean surfaces, sea surface temperature, cloud patterns, small atmospheric particles called aerosols, and the balance of solar energy absorbed and reflected by Earth. The most recent launch was that of Aqua, in May 2002. Aqua carries a synergistic instrument payload and is designed to observe how moisture cycles between Earth's lithosphere (land), hydrosphere (water), atmosphere (air), and cryosphere (ice). This is a very busy year for the EOS program with two additional launches planned. The Solar Radiance and Climate Experiment (SORCE) will make daily measurements of total solar irradiance and spectral solar irradiance between wavelengths of 1 nm and 2000 nm, and the Ice, Clouds and Land Elevation Satellite (ICESat) will measure precisely the elevations of Earth's ice sheets and cloud and aerosol layers in the atmosphere. Aura, the third major EOS mission, is scheduled to launch in 2004 and will carry a suite of instruments that will study the complex chemistry of the atmosphere.

The Earth System Science Pathfinder (ESSP) program is the primary source of exploratory missions to complement EOS. These are smaller and cheaper missions proposed by the scientific community to address specific research questions and they are developed and implemented on a faster schedule. They are competitively selected and led from development through data distribution by a Principal Investigator.

GRACE is the first ESSP mission. It will obtain the most precise measurements of Earth’s gravitational field that have ever been obtained. Improved resolution of the gravity field will lead to important advances in a number of disciplines that study the Earth's climate.

The first ESSP mission is the Gravity Recovery and Climate Experiment (GRACE) — launched in March 2002. Two satellites fly in formation, linked by a microwave ranging instrument and obtain the most precise measurements of the gravity field that have been obtained to date. Many scientific disciplines eagerly await advances that should derive from these data. A second launch in 2004 will deploy two more ESSP satellites — CloudSat and CALIPSO. CloudSat is a satellite experiment designed to measure the vertical structure of clouds from space, which will contribute to better predictions of clouds and effects of clouds on Earth radiation. The Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observer (CALIPSO) will profile the atmosphere using lidar and provide a global set of data on aerosol and cloud properties, radiative fluxes, and atmospheric state. These two spacecraft will fly in formation with Aqua and Aura; the resulting measurements will be intercomparable and will greatly improve our ability to predict future climate change. The Vegetation Canopy Lidar (VCL) — whose principal mission is the characterization of the three-dimensional structure of the Earth’s forest canopy and a global reference data set of topographic heights and transects — is currently being pursued as a technology demonstration. A decision is pending on whether to proceed with a satellite mission.

This drawing depicts the EO-1 spacecraft in orbit. EO-1 is the first NMP launch and carries instruments intended to demonstrate new technologies and serve as a testbed to develop instrumentation for future NASA missions.

The New Millennium Program (NMP) is the principal source of technology demonstration/operational precursor missions. NMP serves as a testbed for the development of cutting edge technology for future Earth science instruments and spacecraft. The first NMP mission, Earth Observing-1 (EO-1), was launched in November 2000. EO-1 carries an Advanced Land Imager designed to continue the measurements made by the Landsat series at a much lower cost and using an instrument that is four to five times smaller than the Enhanced Thematic Mapper Plus (ETM+) instrument on Landsat. Meanwhile, the Hyperion instrument onboard EO-1 tests hyperspectral imaging techniques that can split the signal returned from the surface into hundreds of separate wavelength bands, an order of magnitude improvement in resolution over Landsat. EO-1 is flying in formation with Landsat and Terra so that their observations can easily be compared, making them a physical emblem of the best in remote sensing satellites of today, tomorrow and for decades to come. Another planned NMP mission is the Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) developed at NASA Langley Research Center. GIFTS will allow tracking of the movement of water vapor through the atmosphere in all three spatial dimensions. GIFTS is scheduled to launch in 2005 and will give scientists the ability to observe the space and time distribution of temperature, water vapor, and wind, which will improve weather forecasting.

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Earth Science Enterprise
Introduction
Missions
Data and Information System
Partnerships