This weekend, NASA is planning to launch a spacecraft that can use half a dozen bright-green laser beams to measure seasonal and annual adjustments to Earth’s icy poles.
The mission, referred to as the Ice, Cloud and land Elevation Satellite tv for pc-2 (ICESat-2), will take extremely exact measurements of ice sheet depth, permitting scientists so as to add the third dimension they lose when aerial or space-based pictures of the unfold of ice.
That is essential info on the subject of constructing an correct image of adjustments to ice over time, since thinning ice is simply as regarding as shrinking ice. However simply because it is an vital sort of knowledge does not imply it is simple to collect, which is the place NASA’s affection for space-based lasers comes into play. [How Satellites Watched Birth of a Giant Iceberg in Antarctica (Photos)]
ICESat-2 will carry only one instrument, which is named the Superior Topographic Laser Altimeter System (ATLAS). ATLAS produces six finely tuned laser beams of bright-green mild, which it beams all the way down to bounce off Earth’s floor. (By no means worry, the laser is not sturdy sufficient to soften the ice.)
A lot of these photons are misplaced, scattering off in all instructions. However a treasured few bounce again completely to satisfy the satellite tv for pc once more. Scientists can then translate the spacecraft’s extremely exact measurement of the journey time of every photon — correct to inside a billionth of a second — into the gap it traveled, basically measuring the peak of Earth’s floor at that time.
For sea ice, the highest of the ice is in comparison with the floor of the ocean round it. Then, scientists can calculate how a lot further ice have to be hidden floating within the water. For land ice, the method is a bit more difficult however works on comparable ideas.
The spacecraft produces 10,000 pulses of photons each single second, and for every pulse, the identical course of performs out. ICESat-2 will orbit from pole to pole, taking measurements all alongside the way in which however providing the densest peak maps close to the poles.
Each three months, the spacecraft will journey over a complete of 1,387 orbital paths, then start to retrace its steps, guaranteeing it revisits the identical swath of ice in 91-day increments. And since the instrument creates six separate laser beams in three pairs, scientists can adapt the information if the satellite tv for pc finally ends up straying somewhat from its deliberate path.
That is a significant development from the unique ICESat mission, which operated from 2003 to 2010 however solely produced knowledge utilizing a single laser beam. However, that mission supplied essential proof that the Greenland Ice Sheet was thinning.
The ICESat-2 mission value somewhat over $1 billion and the spacecraft is in regards to the dimension of a Sensible automobile. The preliminary mission is scheduled to final for 3 years, with that timeline starting about two months after launch to permit the workforce to calibrate the devices. That stated, the spacecraft carries sufficient gasoline for 10 years, so the mission might probably be prolonged.
The spacecraft is scheduled to take off from Vandenberg Air Power Base in California on Saturday, Sept. 15, throughout a launch window that can open at 5:46 a.m. native time (eight:46 a.m. EDT, 1246 GMT) and final for two hours and 34 minutes. You’ll be able to watch the launch stay starting at eight:10 a.m. EDT (1210 GMT) on Area.com, courtesy of NASA TV. The launch would be the last journey of the Delta II rocket, which has been flying for 29 years.
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