A
modified Russian ballistic missile successfully launched a $464 million
European science satellite Monday to investigate Earth's water cycle by
measuring moisture levels in soil and salt concentrations in the world's
oceans.
"I'm really happy and
relieved," said Achim Hahne, project manager for the Soil Moisture and
Ocean Salinity satellite.
The SMOS satellite will
spend the next three years creating the best
maps of variations of moisture and salt in land areas and the open ocean.
This data will help weather forecasters, climatologists, and water resource
managers better predict changes in the water cycle.
"SMOS is known as
ESA's water mission," said Mark Drinkwater, head of the European Space
Agency's mission science division. "It's going to help us understand the
complexities of the water cycle on Earth.
Jean-Jacques Dordain, ESA
director general, praised the agency's role in space research focused on planet
Earth.
"ESA is certainly the
space agency of the world making the best efforts for Earth science and climate
(research) and this is a new contribution to the understanding of
climate," Dordain said.
SMOS and another satellite,
called Proba 2, rode into space on the power of a retired ballistic missile
taken from the arsenal of the Russian military.
The Rockot launcher
flickered to life and roared off its launch pad at Plesetsk Cosmodrome at 0150
GMT Monday (8:50 p.m. EST Sunday), disappearing into fog and low clouds in the
predawn hours in northern Russia.
The 95-foot-tall rocket
pitched northward from Plesetsk, flying over the Barents Sea as it jettisoned
its first stage, payload fairing and second stage within five minutes of
liftoff.
The Rockot passed out of
communications range with ground stations moments later, leaving ground
controllers in the blind until the vehicle appeared again over the
Hartebeesthoek communications site in South Africa.
By that point, the 1,451-pound SMOS
satellite was separated from the Rockot's Breeze KM upper stage and
executing programmed commands to deploy the spacecraft's two solar panels.
"Currently, we are
analyzing the telemetry we have received, but we can say the satellite is in
good health and the solar panels have been deployed," said Francois
Bermudo, SMOS project manager at the French space agency, CNES.
SMOS was planned to be
released in an orbit ranging in altitude from 465 miles to 476 miles, with an
inclination of 98.4 degrees. Spacecraft separation occurred at about 0300 GMT
Monday (10 p.m. EST Sunday).
The Breeze upper stage
coasted through space for another circuit of Earth before the $27 million Proba
2 secondary payload was cast free of the rocket.
The 287-pound miniature
satellite will demonstrate 17 new space technologies and carries four
experiments to study the sun's impact on space weather during its two-year
mission. Proba 2 carries test components that could be used on future missions,
including the BepiColombo Mercury probe and the Solar Orbiter spacecraft.
"With Proba 2, we are
preparing for missions 10 years from now," Dordain said.
SMOS will unfurl three
prongs of its Y-shaped antenna Tuesday before the instrument is activated for
testing over the next few weeks.
The L-band MIRAS
instrument, resembling the rotors of a helicopter, is a first-of-a-kind payload
comprising 69 individual antennas stringed together in an inferometer-like
array to maximize the sensor's sensitivity.
Each of the small antennas
will measure faint radio signals emitted by Earth and an on-board processor
will bind the data together before sending the packets back to scientists on
the ground.
The MIRAS radiometer was
built by EADS CASA in Spain.
Development of the
ground-breaking technologies required for such an instrument began in 1992. The
engineering design was finally mature enough for the SMOS mission to be
formally proposed in 1998.
"MIRAS is really a
radio telescope looking down instead of up," said Manuel Martin-Neira,
payload engineer on the SMOS mission. "But to gather an image of useful
resolution would require a classical antenna of at least eight meters (26 feet)
across, far too bulky to fly on the launcher and satellite platform
available."
"When we think about
it's sensitivity, we can think about measuring on the order of one teaspoon of
fresh water in the upper layer of soil," Drinkwater said.
Soil moisture is a key
factor in determining humidity in the atmosphere and the formation of
precipitation.
"Water is the main
driver for the exchanges between the atmosphere and the soil," said Yann
Kerr, SMOS lead investigator at CESBIO, a French space research agency.
"Monitoring these changes help us have better weather forecasts and better
monitor climate changes."
Officials hope data from
SMOS will be fed into numerical weather prediction models to aid meteorologists
in making more accurate forecasts.
"Being able to measure
accurately the water available in the skin of the Earth helps us have a better
understanding of the future weather," Kerr said.
Soil moisture is also
important for researchers studying plant growth and vegetation distributions.
"With SMOS, it will be
the first time that we have measured soil moisture with an accuracy of 4
percent, which will allow us to get 10 to 11 classes of soil wetness,"
said Matthias Drusch, SMOS mission scientist.
SMOS will create maps of
soil moisture in 30-mile-wide blocks and maps of ocean salinity in boxes 120
miles across.
Ocean salinity data from
SMOS will tell scientists how the atmosphere and oceans interact.
Scientists will also gain
new insights on ocean circulation, one of the most important drivers of world
climate. Like conveyor belts, circulation patterns transport warm water to high
latitudes and cool water to low latitudes, moderating the planet's climate.
"It helps to maintain
a balance of temperature across the globe," Drinkwater said.
The temperature and
saltiness of the water help determine ocean circulation patterns.
"That's why SMOS was
really crafted as a mission to get a look at how the salinity varies globally
from one region in the ocean to another, since it's the variations that really
drive the circulation," Drinkwater said.
SMOS data will be used to
make weekly, seasonal and annual maps of salinity and moisture levels.
"The ability of SMOS
is really helped by the fact that we can map the whole globe every few
days," Drinkwater said. "We accumulate data over intervals of two
weeks to a month, and we can make a global picture of the salinity in grid
cells around the globe on those intervals of time."
In its ocean salinity
investigations, the two-dimensional SMOS radiometer can detect one-tenth of a
gram of salt in a liter of water.
All of these measurements
occur as SMOS orbits nearly 500 miles above Earth.
"That's a
mind-boggling thought," Drinkwater said.
SMOS will be the first
satellite capable of gathering global observations of soil moisture and ocean
salinity, building on previous point measurements made by aircraft, ships and
buoys.
NASA is planning two
satellites, Aquarius and SMAP, for launch in 2010 and 2014 to make further measurements
of salinity and soil moisture, respectively.
The SMOS mission's price
tag of about 315 million euros, or $464 million, was divided between ESA and
CNES.
CNES will conduct the
day-to-day operations of the satellite, while ESA will be responsible for
management of the mission and the ground segment.
Normal science activities
should begin about six months after launch, starting two-and-a-half years of
activities to map the distribution of moisture in soil and salt in ocean water.
But SMOS could last much
longer.
SMOS is the second of ESA's
Earth Explorer missions, which were conceived to follow up on observations of
the agency's flagship Envisat satellite launched in 2002.
The gravity-mapping
GOCE spacecraft launched on another Rockot vehicle in March. The CryoSat 2
mission, a replacement for a satellite lost in 2005, is due for launch on a
Dnepr rocket in February to probe the polar ice caps.
"There are many
aspects of Earth we don't know about to the extent necessary. For example, the
gravity field, soil moisture, ocean salinity, to give only three examples which
we are going to measure," said Volker Liebig, director of ESA's Earth
observation programs.
"I like to see the
three missions as very powerful triplets to help address the key climate
questions that we have today," Drinkwater said.
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