heads into 2010 with the bittersweet assignment of retiring the space
shuttle after nearly three decades. But that’s not all the agency has
planned: There are also launches of three new satellites aimed at
better understanding the Earth’s climate and oceans, and the sun.
Two of the probes will examine Earth — specifically
the concentration of salt in the world’s oceans and the presence of
aerosol particles, such as soot, in the atmosphere. A third mission
will study the sun and its effect on space weather including solar
flares that can disrupt communication on Earth.
All three come at a critical time for
Data from the two Earth probes will likely influence global-warming
research, and the trio of launches could serve as bright spots in a
year otherwise dominated by debate over the future of the agency’s
manned space program.
“They are extraordinary timely,” said
Earth-science division, of the two Earth probes. “It is a quest for
understanding of the Earth system and (to improve) our ability to
predict how our wonderful environment and our planet is going to change
in the future.”
Combined, the three missions will cost more than
SOLAR DYNAMICS OBSERVATORY:
—Launch:
—Cost:
—Mission duration: At least five years
—Overseen by: Goddard Space Flight Center in
SDO’s mission: Study how the sun works and its effect on space weather.
Predicting weather in space can be tricky.
Scientists hope this satellite can help astronomers better anticipate
the solar flares, sunspots and magnetic storms that come from the sun
and can jeopardize astronauts in space and electrical communications on
Earth.
instruments meant to meticulously document solar activity: a high-speed
camera, a device that will record the sun’s ultraviolet brightness and
an imager that uses sounds waves to map the sun’s interior — similar to
how an ultrasound produces fetal images.
The aim is to better understand the sun’s magnetic
field, which influences the development of sunspots, solar flares and
magnetic storms, called coronal mass ejections. That in turn should
enable better forecasting of solar eruptions, in much the same way
hurricane forecasters use broad climate conditions to estimate the
number of storms each season.
The key is learning more about the sun’s solar
cycle, which every 11 years or so flips the star’s magnetic pole from
north to south (or back again). This change triggers intense solar
activity and blasts cosmic rays toward Earth that can disrupt cell
phones and cause widespread blackouts.
“The sun hasn’t changed very much. But human
technology has. So it’s more important to understand the sources of the
ways these changes affect Earth,” said
AQUARIUS:
—Launch: TBD in 2010 from
—Cost:
—Mission duration: At least three years
—Overseen by:
Aquarius’ mission: Provide global measurements of saline levels in seawater and how that relates to Earth’s water cycle.
For the past 100 years, scientists have relied on
ships and buoys to provide estimates on how salt is distributed
throughout the world’s oceans. The readings were incomplete, however,
and didn’t provide timely readings of changes in salinity.
The Aquarius satellite could change that. Using
three onboard radiometers that can detect small changes in salt levels,
it will enable scientists — for the first time — to build a global map
of ocean-surface salinity and track how salt moves through ocean
currents.
The new data could be critical in learning how ocean
circulation and weather patterns such as El Nino, respond to global
warming. Fluctuations in salt levels generally result from fluctuations
in rainfall and evaporation, said
For instance, the readings could give oceanographers
a better idea of how fresh water from melting polar ice caps is being
distributed globally.
Aquarius will be carried aloft by the SAC-D spacecraft, built by the
“We want to utilize this data to improve our climate
models. … We don’t know what the fate of the water (from melting
polar ice caps) is,” Lagerloef said.
GLORY:
—Launch:
—Cost:
—Mission duration: At least three years
—Overseen by: Goddard Space Flight Center in
Glory’s mission: Observe the effects of aerosolized particles on the Earth’s climate.
One of the big questions in global-warming research
is the effect of aerosolized particles — from smog, auto exhaust,
factory chimneys, volcanic eruptions and myriad other sources — on
Earth’s temperature.
It is thought that aerosols could counteract the
effects of greenhouse warming caused by growing levels of carbon
dioxide by deflecting some of the sun’s rays. Major volcanic eruptions,
for instance, have lowered global temperatures for several years by
flinging sulfur dioxide into the atmosphere, which acts as a kind of
sunscreen.
But scientists have been unable to accurately
measure the influence of aerosols — or even say with certainty that all
of them have a cooling effect. Some climatologists have suggested that
black-carbon aerosols — such as soot — actually absorb the sun’s heat,
rather than reflect it, and result in a warmer Earth.
The Glory probe will try to catalog the different
types of aerosols in the atmosphere. Understanding the composition
could help scientists better understand their net effect on climate
change.
“We know that aerosols are having a significant effect, but we don’t know the magnitude of that effect,” said
