The European Space Agency plans to sync two satellites to create a single, virtual telescope. If it works, it could mean hugely increased telescopic power.
The ESA Proba-3 project, scheduled for launch in 2018, is designed to not only carry out a practical task (studying our Sun in greater detail) but to test a principle: that two satellites can orbit and maintain their relative positions.
The goal is to have the satellite crafts controlled using refined versions of existing technology. Both will use radios and lasers to measure their positions, then use miniature thrusters to adjust their position where needed. According to the Observer newspaper, the goal is to have the two satellites 150 meters apart, keeping synced to within one millimeter.
To take advantage of this precision, the ESA will mount a disc on one of the satellites such that it creates a permanent solar eclipse for the second satellite. This will allow the second telescope to study the Sun’s corona) without being blinded by the Sun itself. One goal is to find out more about why the corona, the Sun’s outer gaseous layer, is hotter than the surface of the Sun itself.
If Proba-3 is able to maintain the sync between the two satellites, it could lead to future projects where two or even more craft can be sent into orbit together, each performing a different role to make up a virtual telescope.
That could overcome current limitations by which it’s only possible to carry a certain size of telescope into space in one piece, in turn limiting the distance over which the telescope can operate, the level of detail it can capture, or both. The alternative, building gigantic telescopes to use on Earth, is limited by the distorting effects of our own atmosphere.