Roundup: NASA launches twin spacecraft to study sun in 3D

NASA successfully launched twin spacecraft at 8:52 p.m. EDT on Wednesday (0052 GMT Thursday) from Cape Canaveral Air Force Station, Florida, according to NASA TV.

The two-year mission will provide the first-ever stereoscopic (3D) measurements to study the sun and its massive, weather-disrupting eruptions.

The twin spacecraft, stacked one on top of the other, blasted off aboard a single Delta II rocket, said NASA commentator. The spacecraft's launch was delayed several times this year because of technical problems.

NASA said today the twin spacecraft began an illuminating mission investigating how special solar storms, called "coronal mass ejections (CME)," start and flow around the Earth. The duo will observe solar eruptions in glorious 3D.

NASA devised a unique launch of the two solar-powered observatories, using the moon's gravity like a pinball flipper to send them into opposite and slightly distinct orbits around the sun.

The mission, known as STEREO, for Solar Terrestrial Relations Observatory, will be the first to view the sun from two separate vantage points outside Earth's orbit.

By simultaneously measuring and recording solar eruptions, the two nearly-identical spacecraft will act like a pair of human eyes, giving a "unique and revolutionary view" of the flow of energy between the sun and Earth.

Over the two-year mission cycle, the two spacecraft, working in tandem in different orbits, will slowly drift further apart while tracking the sun.

Scientists hope the mission will glean insight into solar activities such as CME. CME is the most violent explosions in our solar system, and the huge eruptions will blast a billion tonnes of solar plasma into space.

When aimed at the Earth, such storms can wreck satellites and cause power and telecommunications outages on Earth. They can also endanger astronauts on journeys beyond the Earth's magnetic field.

"In terms of space-weather forecasting, we're where weather forecasters were in the 1950s," mission scientist Michael Kaiser said. Now, under the help of STEREO, the prediction of solar eruptions can be greatly improved.

There are four instrument packages mounted on each of the two STEREO spacecraft: an extreme ultraviolet imager, two white-light coronagraphs and a heliospheric imager. These instruments will study the 3D evolution of CME's from birth at the sun's surface through the corona and interplanetary medium to its eventual impact at Earth.

In the meantime, the mission will also help researchers predict which solar storms could endanger astronaut. NASA hopes information about the solar eruptions helps the astronauts who fly to moon and eventually Mars in the coming decades.

Source: Xinhua