SOLAR SCOUT: The Solar Dynamics Observatory, shown here in its protective fairing as it is lifted onto an Atlas 5 rocket for launch, should provide an unprecedented bounty of data about the workings of the sun.
Image: NASA
NASA's Solar Dynamics Observatory is what might be called a satellite for the information age. It is designed to provide scientists who study the sun with a torrent of data—the space agency says the observatory will return 150 million bits of data about Earth's host star per second, or about 1.5 terabytes per day.
The spacecraft, known as SDO, is scheduled to launch into orbit at 10:26 A.M. Wednesday from Cape Canaveral Air Force Station in Florida, weather permitting. Its data stream is so broad that the observatory will have a dedicated pair of 18-meter radio dishes near Las Cruces, N.M., at its disposal for downlink; the satellite's geosynchronous orbit will keep it within radio range of New Mexico at all times.
The data SDO gathers should help hone forecasts of solar activity and the space weather it creates, which can wreak havoc on and around Earth with storms of charged particles and radiation. With advance warning about an impending solar storm, astronauts in orbit could seek refuge in shielded compartments, utilities could brace the power grid for disturbances, communications firms and the military could place their satellites in safe mode, and airplanes could change course to avoid the most dangerous altitudes and routes. (Earth's magnetic shielding is weakest at the poles, for instance, so transpolar flights would be at greater risk from solar storms.)
"Our big goal is to learn how to predict what the sun is going to do," says Dean Pesnell, SDO project scientist at NASA Goddard Space Flight Center in Greenbelt, Md. Pilots and astronauts, he says, would like to know solar forecasts hours or even days in advance, whereas the U.S. Air Force would like weeks of notice for mission-planning purposes. "And I'm interested, scientifically, in predicting what's going to happen a year or 10 years from now," Pesnell says.
To that end, SDO carries three scientific instruments, including the Atmospheric Imaging Assembly, a set of four telescopes that return eight images every 10 seconds in a variety of light bands, from the visible to the shorter-wavelength extreme ultraviolet. Those wavelengths reveal the roiling activity, such as explosive solar flares and looping prominences, on and above the sun's surface. Each image packs enough pixels—more than 4,000 a side—to fill 15 high-definition television screens.
A second instrument, the Extreme Ultraviolet Variability Experiment, uses spectrographs to break down the sun's extreme UV light into its component wavelengths with unprecedented resolution. The goal is to track the sun's shifting irradiance in the extreme UV, where high-energy photons pack a dangerous punch, potentially allowing heliophysicists to link variations in the extreme UV to other solar phenomena.
But Pesnell is most excited about the third instrument. "The one I think is the coolest is the Helioseismic and Magnetic Imager," he says. The instrument monitors magnetic flux and takes helioseismology readings, tracking the propagation of sound waves across the sun's surface. "It looks amazingly like ocean waves, if you can imagine looking down on an ocean and seeing waves just going in all directions," Pesnell says. "Well, if you study those waves you can infer what's going on inside the sun."
A recent study led by National Oceanic and Atmospheric Administration research scientist Alysha Reinard showed how helioseismology can be used to track swirling plasma flows in the sun and predict solar flares with unprecedented accuracy. But that forecasting approach is only as good as its data; at present the false alarm rate is above 50 percent. Helioseismology data from by SDO should lead to more reliable flare forecasting, which would be a boon to monitors of space weather.
SDO is the first mission to reach fruition from NASA's Living with a Star program, which seeks to better characterize how solar activity affects life on Earth. The mission will cost an estimated $850 million, including five years of operations, according to NASA. But with nearly 1.5 metric tons of maneuvering fuel onboard, SDO could well operate 10 years or longer.
As Big Hurricane Season Looms, NOAA Chief Calls Satellite Cuts a "Disaster"
Why Does NASA Launch Space Shuttles from Such a Weather-Beaten Place?
News Bytes of the Week--Tomatoes get thumbs-up; but peppers still hot
The Moon That Would Be a Planet
News Bytes of the Week—Headless Snake Bites Hapless Man
Titan Found to Be Rather Like Early Earth
Japanese Satellite First to Use Magnetic Memory
10 Comments
Add CommentThere seems to be some inconsistency in the article; 150Mbits/sec does not equate to 1.5TB/day, far from it.
Reply | Report Abuse | Link to this150Mbits = 18.75MB
18.85MB/sec * 60 sec/hour = 1.125TB/hour
1.125TB/hour * 24 hour/day = 27TB/day
If the satellite is transmitting 150Mbits/sec of data continuously, then it is only transmitting for the equivalent of one and a third hours. A little clarification would be great.
The article says 150 million BITS, not MEGABITS. Their calculation is exactly correct as that yields 1.47338141687214 TB/day.
Reply | Report Abuse | Link to this150 Million bits = 17.8813934326172 Megabytes
17.8813934326172 * 60 seconds in a minute = 1072.883605957032 Megabytes/minute
1072.883605957032 * 60 minutes in an hour = 64373.01635742192 Megabytes/hour
64373.01635742192 * 24 hours in a day = 1.47338141687214 TB/day
MATW,
Reply | Report Abuse | Link to thisI did make a mistake in that I jumped from MB to TB instead of GB and that I went from seconds to hours instead of minutes. I also incorrectly equated 1 million bytes to 1MB instead of 1048576 bytes to 1MB. Thank you for the correction.
Regardless.. 1.5TB/day is a lot of info about the sun! I hope they take lots of video.
Reply | Report Abuse | Link to thisCrucialitis - The article seems to explain that at least two of the instruments record image data, so there should be cool movies on the internet someday soon.
Reply | Report Abuse | Link to thisWhy a Geosychronous orbit? These orbits have eclipse periods when the sun cannot be "seen." An orbit at the L-1 libration point (where many solar viewing satellites are) would give 24/7 views of the sun.
Reply | Report Abuse | Link to thisPeterT
PeterT...that's what i was thinking...why not have it observing 24/7....like soho...
Reply | Report Abuse | Link to thisI hope their being careful. You wouldn't want to piss off the sun.
Reply | Report Abuse | Link to thisIt would not be possible to piss on The Sun, my maths teacher told me.
Reply | Report Abuse | Link to thisWill the SDO satellites tools be able to tell what causes the Sun's surface to rise up for hundreds of yards at switching about and mostly equatorial sites? Would that rising be equated to the many zone's fusion reaction's electromagnetic energy pulses chasing by ponderomotive force the electrons from the helium atoms that make up the tachocline sphere. With that in effect, and as each zones EM output is cut off that would possibly be the reason for the surface sites to redraw down to their former sites. What I am wondering; if my surmise is correct; and if it could be detirmined about the sequences of the separate rising sites, then a fusion reaction rythym, or firing order could be detirmined.
Reply | Report Abuse | Link to thisWith sixteen ionized proton swirls being cited beneath the equatorial belt in the convection zone, would that not lead one to assume that there are also sixteen fusion reactor zones in the radiative zone's cavernous space. With that being as so, then would each reactor zone would have its own magnetic segment, and with the sixteen making up a toroid inside of the tachocline. With that it might be easier to understand how the tachocline material remains as a single unit, if one considers the action provided to its atoms from each laser-like pulsation of the fusion reaction moments.
With each zone having its own malleable magnetic segment, as one segment expands from its reactor's process, that event would squash neighbor zones, which squashing could either compress a fresh load of ionized protons from the core's irradiated surface to build up its pressure and temperature, or squeeze out the effluent from a five minute ago firing in a neighbor zone. Perhaps it could be seen that the solar fusion reactor system in the radiative zone is a four sectioned four cycle engine? With that in effect then the energy transfer systems might more easily be recognized, such that all of the systems may be credited as being the total of the Solar Dynamo.
Then there are the short-lived spicules, are they each related to the solar dynamo? Being that they spear through the chromosphere's 10,000 degree heat, could it be that in their short magnetic life that they attract positive protons from the chromosphere, puncture through the chromosphere's magnetic cap and release the protons as up and coming bits of solar wind that are being released into the lower corona in what have been stated are mushrooming clouds called 'Celestial Moss'?
For those bits of future solar wind to scream out in great white sheets from the upper corona, something holds back.