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Tiny IceCube Satellites first global map of ice clouds



NASA

Astronauts on Earth see large white clouds spreading from the International Space Station over the planet. You can not distinguish a gray rain cloud from a swollen white cloud. While satellites can see through many clouds and appreciate the liquid rainfall they hold, they can not see the smaller ice particles that produce enormous rain clouds.

An experimental small satellite has filled this gap and captured the little boy's first global image Frozen particles in clouds, usually called ice clouds.

Launched in May 2017 from the space station, IceCube tests instruments for their ability to measure the small, frozen crystals that make up ice clouds in space. "Heavy rains come from ice clouds," said Dong Wu, head of the IceCube project at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Ice clouds begin as tiny particles in the atmosphere. By absorbing moisture, the ice crystals grow and become heavier so that they fall to lower altitudes. Eventually, the particles become so heavy that they will fall and melt to form raindrops. The ice crystals can also simply stay in the air.

Like other clouds, ice clouds affect the Earth's energy budget by either reflecting or absorbing the sun's energy and influencing heat release from Earth into space. Therefore, ice clouds are key variables in weather and climate models.

This is a three month average of ice clouds. The brightest peak areas represent the largest concentration of ice clouds. They are also the places with heavy rainfall underneath. They reach to the top of the troposphere from the deepest convection, which is usually strongest in the tropics.

[IceCube has created a global map of these ice clouds around the planet, which could someday help improve models and forecasts. Credits: NASA Goddard/ Jennifer Brill]

The measurement of atmospheric ice on a global scale remains very uncertain, since satellites could not detect the amount of small ice particles in the clouds since these Particles too opaque to infrared and visible sensors are to invade. To overcome this limitation, IceCube was equipped with a submillimeter radiometer that bridges the lack of sensitivity between infrared and microwave wavelengths.

Although it weighs only 10 pounds and is about the size of a loaf of bread, IceCube is a true three-axis attitude control spacecraft, deployable solar arrays, and a deployable UHF communications antenna. The CubeSat rotates like a plate that rotates on a pole about its axis. It points to the earth to take a measurement and then looks at the cold room for calibration.

Originally a 30-day technology demonstration mission, IceCube is fully operational in near-Earth orbit almost a year later, measuring ice clouds and providing data "good enough to make real science," Wu said.

[The bread loaf-sized IceCube was deployed from the International Space Station in May 2017. One month later, it began science operations gathering global data about atmospheric ice clouds in the submillimeter wavelengths. Credits: NASA]

"The hard part in developing the CubeSat is keeping the commercial parts in space," said Tom Johnson, Goddard's Small Satellite Manager stationed at the NASA Wallops Flight Facility in Virginia. "We bought commercial components for IceCube and spent a lot of time testing the components to make sure all parts worked."

Last year, engineers tested the limits of the satellite in orbit. They wanted to see if the device's batteries stored enough energy for 24 hours. IceCube charges its batteries when the sun shines on its solar panels. During the test, security precautions prevented the satellite from losing all its power and ending the mission; The test was successful. The batteries ran the IceCube all night and were recharged during the day. This change made the CubeSat even more valuable for the collection of scientific data.

While the IceCube team planned to operate in space for 30 days, "it does not cost much to keep it going," Johnson said, adding to the mission because of the outstanding science that IceCube performs. We download the data eight to ten times a week. Even if we miss a week, the CubeSat can save a few weeks of data. Johnson says he's not surprised at how long IceCube has taken. "It'll take about a year to get it back in."

Earth's atmosphere and burns there. "

The IceCube team built the spacecraft using NASA Earth Observation (InVEST) technology from the Earth Science Technology Office (ESTO) program and NASA's Science Mission Directorate CubeSat Initiative [19659002] Small satellites, including CubeSats, are playing an increasingly important role in NASA's exploration, technology demonstration, scientific research, and educational research, in planetary space exploration, fundamental space and space science, and the development of groundbreaking scientific tools such as state-of-the-art laser communications, satellites used for satellite communications and autonomous motor skills.

Ed for meteorologist Mace Michaels [19659019]
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