A NASA satellite that promises to deliver an unprecedented volume of data about the workings of the sun launched successfully atop an Atlas 5 rocket Thursday. The Solar Dynamics Observatory, or SDO, lifted off from Cape Canaveral Air Force Station in Florida at 10:23 A.M. (Eastern Standard Time) after a one-day delay due to high winds at the launch site. The satellite separated from the upper rocket stage and deployed its solar arrays about two hours later.
SDO, expected to cost $850 million over five years of operation, carries three instruments that NASA estimates will deliver 1.5 terabytes of data on the sun's workings every day. The torrent will include dozens of ultrahigh-resolution images each minute and helioseismology readings that track the propagation of acoustic waves across the sun's surface. Those waves allow heliophysicists to make inferences about the convective inner workings of the sun, allowing for more reliable forecasts of solar activity and the space weather it creates, which can endanger satellites, power grids and astronauts in orbit.
The satellite will circle Earth in a geosynchronous orbit that allows for constant contact with a pair of dedicated radio dishes in New Mexico. That way, SDO can continually offload its data stream without having to store or heavily process information on-board. The downside of a geosynchronous orbit is that twice a year, near equinox, Earth will block SDO's view of the sun. But SDO project scientist Dean Pesnell of the NASA Goddard Space Flight Center in Greenbelt, Md., says that the spacecraft's minders will use those periods for calibration and tune-up of the satellite.
Launch photo: NASA TV