At a meeting in Paris on Tuesday, the European Space Agency approved two new space science missions to begin before the end of the decade.

The Solar Orbiter, set to launch in 2017, is designed to help scientists better understand how the Sun influences the Earth's environment, and how solar wind - the constant stream of energy particles from the Sun - affects the solar system. The second project, a space telescope called Euclid, is slated for blast-off in 2019.

Euclid will be able to see cosmological objects 10 billion light-years away from Earth, and will particularly be designed to further the study of dark energy, the mysterious expansionary force that causes the universe's rate of expansion to accelerate. The three American scientists involved in dark energy's discovery were awarded the Nobel Prize on Tuesday.

These two missions are the first in the ESA's Cosmic Vision 2015-2025 Plans, which outlines research priorities for the coming decade.

Pekka Janhunen pioneered this electric sail design, is a new space propulsion concept

Orbiter to make 'in situ' measurements

European astronomers say that these two missions will vastly improve knowledge of these types of stellar and cosmological phenomena.

"For Solar Orbiter, where I lead one of the ten instruments onboard, the mission will make huge leaps in our understanding of how the Sun makes the solar wind and how its 11 year sunspot cycle, which is actually a cycle in its magnetic field, actually works," wrote Tim Horbury, a physics professor at the Imperial College London, in an e-mail sent to Deutsche Welle.

"Solar Orbiter will do this by flying closer to the Sun then ever before, closer than Mercury, and taking pictures of the Sun's surface and atmosphere at very high resolution. It will also measure the solar wind and magnetic field coming off the Sun," Horbury said.

"By going close, we can link together where the different bits of solar wind come from. Incredibly, we currently just don't know where on the Sun about half of the solar wind is born."

Pekka Janhunen, a researcher at the Finnish Meteorological Institute, agreed, noting that scientists in his field say that little is known about how solar wind is created from the sun.

"We already know rather lot about how the solar wind behaves after it has left its creation region (the solar corona), but the basic question about the 'first mover' or primary engine of the solar wind is still largely open," he wrote in an e-mail. "Solar Orbiter will make direct local ('in situ') measurements very close to the Sun that are critical in increasing our understanding about this issue."

Euclid will be able to see into the farthest corners of the universe

'Major step' for dark energy research

ESA officials say that Euclid, meanwhile, will attempt to gain new insight into the farthest reaches of the galaxy and try to understand one of the universe's most bizarre, but fundamental, forces.

"Euclid is a major step forward," said Henk Hoekstra, an astronomy professor at the Leiden Observatory in the Netherlands, and one of the planners of the Euclid mission.

He said the new telescope should expand the current level of accuracy for dark energy measurements by two orders of magnitude.

"Dark energy was discovered only 14 years ago," he added. "It makes up 70 percent of the universe because it's a fairly subtle effect. It's only with new techniques that we are now able to make the next push forward."

Author: Cyrus Farivar

Editor: Stuart Tiffen