![]() Artist's view of SMOS | |
Mission type | Earth observation |
---|---|
Operator | ESA |
COSPAR ID | 2009-059A |
SATCAT no. | 36036 |
Website | www |
Mission duration | Planned: 3 years Elapsed: 14 years, 5 months, 21 days |
Spacecraft properties | |
Bus | Proteus |
Manufacturer | Thales Alenia Space CNES |
Launch mass | 658 kilograms (1,451 lb) |
Dry mass | 630 kilograms (1,390 lb) |
Dimensions | 2.4 by 2.3 metres (7.9 ft × 7.5 ft) (diameter) |
Power | up to 1065 watts |
Start of mission | |
Launch date | 2 November 2009, 14:21:00 UTC [1] |
Rocket | Rokot/Briz-KM |
Launch site | Plesetsk 133/3 |
Contractor | Eurockot |
Orbital parameters | |
Reference system | Geocentric |
Regime | Sun-synchronous |
Perigee altitude | 765 kilometres (475 mi) [2] |
Apogee altitude | 766 kilometres (476 mi) [2] |
Inclination | 98.44 degrees [2] |
Period | 100.02 minutes [2] |
Repeat interval | 23 days |
Epoch | 25 January 2015, 00:45:13 UTC [2] |
Transponders | |
Band | S Band (TT&C support) X Band (science data acquisition) |
Bandwidth | up to 722 kbit/s download (S Band) up to 18.4 Mbit/s download (X Band) up to 4 kbit /s upload (S Band) |
Instruments | |
MIRAS: Microwave Imaging Radiometer using Aperture Synthesis | |
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Soil Moisture and Ocean Salinity (SMOS) is a satellite which forms part of ESA's Living Planet Programme. It is intended to provide new insights into Earth's water cycle and climate. In addition, it is intended to provide improved weather forecasting and monitoring of snow and ice accumulation. [3] [4] [5] [6]
The project was proposed in November 1998; in 2004 the project passed ESA-phase "C/D" and, [7] after several delays, it was launched on 2 November 2009 from Plesetsk Cosmodrome on a Rockot rocket. [8] The first data from the MIRAS (Microwave Imaging Radiometer using Aperture Synthesis) instrument was received on 20 November 2009. [9] The SMOS programme cost is about €315 million ($465 million; £280 million). It is led by ESA but with significant input from French and Spanish interests. [8]
The satellite is part of ESA's Earth Explorer programme – satellite missions that are performing innovative science in obtaining data on issues of pressing environmental concern. The first is already complete – a mission called GOCE, which mapped variations in the pull of gravity across the Earth's surface. SMOS was the second Explorer to launch; and was followed by CryoSat-2 (the first CryoSat failed on launch), Swarm (spacecraft), and ADM-Aeolus.
The satellite was launched on 2 November 2009 (04:50 (01:50 GMT)) to a nearly circular orbit of 763 km aboard a Rokot, a modified Russian Intercontinental Ballistic Missile (ICBM) SS-19 launched from a decommissioned SS-19 launcher from Northern Russia's Plesetsk Cosmodrome. [4] [10] The SMOS satellite was launched together with the Proba-2, a technology demonstration satellite. [11] [12]
The goal of the SMOS mission is to monitor surface soil moisture with an accuracy of 4% (at 35–50 km spatial resolution). [7] This aspect is managed by the HYDROS project. Project Aquarius will attempt to monitor sea surface salinity with an accuracy of 0.1 psu (10- to 30-day average and a spatial resolution of 200 km x 200 km). [7] [13]
Soil moisture is an important aspect of climate, and therefore forecasting. Plants transpire water from depths lower than 1 meter in many places and satellites like SMOS can only provide moisture content down to a few centimeters, but using repeated measurements in a day, the satellite can extrapolate soil moisture. [4] [5] The SMOS team of ESA hope to work with farmers around the world, including the United States Department of Agriculture to use as ground-based calibration for models determining soil moisture, as it may help to better understand crop yields over wide regions. [14]
Ocean salinity is crucial to the understanding of the role of the ocean in climate through the global water cycle. [15] Salinity in combination with temperature determine ocean circulation by defining its density and hence thermohaline circulation. [16] Additionally, ocean salinity is one of the variables that regulate CO2 uptake and release and therefore has an effect on the oceanic carbon cycle. [17]
Information from SMOS is expected to help improve short and medium-term weather forecasts, and also have practical applications in areas such as agriculture and water resource management. In addition, climate models should benefit from having a more precise picture of the scale and speed of movement of water in the different components of the hydrological cycle. [8]
SMOS has been used to improve hurricane forecasting by collecting hurricane surface-level wind speed data using its novel microwave imaging radiometer, which can penetrate the thick clouds surrounding a cyclone. Hurricanes that have been studied by SMOS include Hurricane Florence, Typhoon Mangkhut, and Typhoon Jebi. [18]
The SMOS satellite carries a new type of instrument called Microwave Imaging Radiometer with Aperture Synthesis (MIRAS). Some eight metres across, it has the look of helicopter rotor blades; the instrument creates images of radiation emitted in the microwave L-band (1.4 GHz). MIRAS will measure changes in the wetness of the land and in the salinity of seawater by observing variations in the natural microwave emission coming up off the surface of the planet. [6] [8] [13]
The CNES Satellite Operations Ground Segment will operate the spacecraft with telecommunications from ESA's S-band facility located in Kiruna, Sweden. The Data Processing Ground Segment (CDTI, Villafranca, Spain) will process SMOS data through the X-band. Higher level processing of information will be done by scientists globally. [4]
A microwave radiometer (MWR) is a radiometer that measures energy emitted at one millimeter-to-metre wavelengths (frequencies of 0.3–300 GHz) known as microwaves. Microwave radiometers are very sensitive receivers designed to measure thermally-emitted electromagnetic radiation. They are usually equipped with multiple receiving channels to derive the characteristic emission spectrum of planetary atmospheres, surfaces or extraterrestrial objects. Microwave radiometers are utilized in a variety of environmental and engineering applications, including remote sensing, weather forecasting, climate monitoring, radio astronomy and radio propagation studies.
European Remote Sensing satellite (ERS) was the European Space Agency's first Earth-observing satellite programme using a polar orbit. It consisted of two satellites, ERS-1 and ERS-2, with ERS-1 being launched in 1991.
Jason-1 was a satellite altimeter oceanography mission. It sought to monitor global ocean circulation, study the ties between the ocean and the atmosphere, improve global climate forecasts and predictions, and monitor events such as El Niño and ocean eddies. Jason-1 was launched in 2001 and it was followed by OSTM/Jason-2 in 2008, and Jason-3 in 2016 – the Jason satellite series. Jason-1 was launched alongside the TIMED spacecraft.
CryoSat is an ESA programme to monitor variations in the extent and thickness of polar ice through use of a satellite in low Earth orbit. The information provided about the behaviour of coastal glaciers that drain thinning ice sheets will be key to better predictions of future sea level rise. The CryoSat-1 spacecraft was lost in a launch failure in 2005, however the programme was resumed with the successful launch of a replacement, CryoSat-2, launched on 8 April 2010.
Aeolus, or, in full, Atmospheric Dynamics Mission-Aeolus (ADM-Aeolus), was an Earth observation satellite operated by the European Space Agency (ESA). It was built by Airbus Defence and Space, launched on 22 August 2018, and operated until it was deorbited and re-entered the atmosphere over Antarctica on 28 July 2023. ADM-Aeolus was the first satellite with equipment capable of performing global wind-component-profile observation and provided much-needed information to improve weather forecasting. Aeolus was the first satellite capable of observing what the winds are doing on Earth, from the surface of the planet and into the stratosphere 30 km high.
Copernicus is the Earth observation component of the European Union Space Programme, managed by the European Commission and implemented in partnership with the EU Member States, the European Space Agency (ESA), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), the European Centre for Medium-Range Weather Forecasts (ECMWF), the Joint Research Centre (JRC), the European Environment Agency (EEA), the European Maritime Safety Agency (EMSA), Frontex, SatCen and Mercator Océan.
Aquarius was a NASA instrument aboard the Argentine SAC-D spacecraft. Its mission was to measure global sea surface salinity to better predict future climate conditions.
PROBA-2 is the second satellite in the European Space Agency's series of PROBA low-cost satellites that are being used to validate new spacecraft technologies while also carrying scientific instruments. PROBA-2 is a small satellite (130 kg) developed under an ESA General Support Technology Program (GSTP) contract by a Belgian consortium led by Verhaert of Kruibeke, Belgium. The nominal mission duration was two years. As of 2022, the mission continues.
Sentinel-3 is an Earth observation heavy satellite series developed by the European Space Agency as part of the Copernicus Programme. It currently consists of 2 satellites: Sentinel-3A and Sentinel-3B. After initial commissioning, each satellite was handed over to EUMETSAT for the routine operations phase of the mission. Two recurrent satellites— Sentinel-3C and Sentinel-3D— will follow in approximately 2025 and 2028 respectively to ensure continuity of the Sentinel-3 mission.
The Living Planet Programme (LPP) is a programme within the European Space Agency which is managed by the Earth Observation Programmes Directorate. LPP consists of two classes of Earth observation missions including research missions known as Earth Explorers, and the Earth Watch class of missions whose objective is to develop support operational applications such as numerical weather forecasting or resource management.
Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) is the major instrument on the Soil Moisture and Ocean Salinity satellite (SMOS). MIRAS employs a planar antenna composed of a central body and three telescoping, deployable arms, in total 69 receivers on the Unit. Each receiver is composed of one Lightweight Cost-Effective Front-end (LICEF) module, which detects radiation in the microwave L-band, both in horizontal and vertical polarizations. The aperture on the LICEF detectors, planar in arrangement on MIRAS, point directly toward the Earth's surface as the satellite orbits. The arrangement and orientation of MIRAS makes the instrument a 2-D interferometric radiometer that generates brightness temperature images, from which both geophysical variables are computed. The salinity measurement requires demanding performance of the instrument in terms of calibration and stability. The MIRAS instrument's prime contractor was EADS CASA Espacio, manufacturing the payload of SMOS under ESA's contract.
The Earth and Mission Science Division is a group of European Space Agency (ESA) staff mission scientists, contractors, research fellows, young graduates, trainees, and administrative staff working within the Climate Action, Sustainability and Science Department of the Directorate of Earth Observation Programmes. The Division is located at ESA's European Space Research and Technology Centre in Noordwijk, South Holland, The Netherlands.
CryoSat-2 is a European Space Agency (ESA) Earth Explorer Mission that launched on April 8, 2010. CryoSat-2 is dedicated to measuring polar sea ice thickness and monitoring changes in ice sheets. Its primary objective is to measure the thinning of Arctic sea ice, but has applications to other regions and scientific purposes, such as Antarctica and oceanography.
Soil Moisture Active Passive (SMAP) is a NASA environmental monitoring satellite that measures soil moisture across the planet. It is designed to collect a global 'snapshot' of soil moisture every 2 to 3 days. With this frequency, changes from specific storms can be measured while also assessing impacts across seasons of the year. SMAP was launched on 31 January 2015. It was one of the first Earth observation satellites developed by NASA in response to the National Research Council's Decadal Survey.
Swarm is a European Space Agency (ESA) mission to study the Earth's magnetic field. High-precision and high-resolution measurements of the strength, direction and variations of the Earth's magnetic field, complemented by precise navigation, accelerometer and electric field measurements, will provide data for modelling the geomagnetic field and its interaction with other physical aspects of the Earth system. The results offer a view of the inside of the Earth from space, enabling the composition and processes of the interior to be studied in detail and increase our knowledge of atmospheric processes and ocean circulation patterns that affect climate and weather.
SAC-D, also known as Aquarius after its primary instrument, is an Argentine Earth science satellite built by INVAP and operated by CONAE. SAC-D was launched from Vandenberg Air Force Base on 10 June 2011, with a planned mission life of five years. Due to a power system failure, the mission was ended on 8 June 2015.
Sea ice thickness spatial extent, and open water within sea ice packs can vary rapidly in response to weather and climate. Sea ice concentration are measured by satellites, with the Special Sensor Microwave Imager / Sounder (SSMIS), and the European Space Agency's Cryosat-2 satellite to map the thickness and shape of the Earth's polar ice cover. The sea ice volume is calculated with the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS), which blends satellite-observed data, such as sea ice concentrations into model calculations to estimate sea ice thickness and volume. Sea ice thickness determines a number of important fluxes such as heat flux between the air and ocean surface—see below—as well as salt and fresh water fluxes between the ocean since saline water ejects much of its salt content when frozen—see sea ice growth processes. It is also important for navigators on icebreakers since there is an upper limit to the thickness of ice any ship can sail through.
NOAA-20, designated JPSS-1 prior to launch, is the first of the United States National Oceanic and Atmospheric Administration's latest generation of U.S. polar-orbiting, non-geosynchronous, environmental satellites called the Joint Polar Satellite System. NOAA-20 was launched on 18 November 2017 and joined the Suomi National Polar-orbiting Partnership satellite in the same orbit. NOAA-20 operates about 50 minutes behind Suomi NPP, allowing important overlap in observational coverage. Circling the Earth from pole-to-pole, it crosses the equator about 14 times daily, providing full global coverage twice a day. This gives meteorologists information on "atmospheric temperature and moisture, clouds, sea-surface temperature, ocean color, sea ice cover, volcanic ash, and fire detection" so as to enhance weather forecasting including hurricane tracking, post-hurricane recovery by detailing storm damage and mapping of power outages.
Biomass is an Earth observing satellite planned for launch by the European Space Agency (ESA) in 2024 on a Vega launch vehicle.
Eni G. Njoku is a Nigerian-American scientist specializing in microwave remote sensing. He worked at the Jet Propulsion Laboratory (JPL), California Institute of Technology, where he was responsible for developing techniques for sea surface temperature and soil moisture remote sensing using microwave radiometers. He produced the first microwave-derived sea surface temperature maps from space, and developed the first application of deployable mesh antennas for satellite Earth observation. From 2008-2013, he served as project scientist of NASA's first soil moisture mission, the Soil Moisture Active Passive (SMAP) mission, launched in 2015.