A mission by the European Space Agency to create artificial eclipses in space is nearing a crucial milestone in development. The critical design review will take place this autumn and determine whether the spacecraft can proceed to fabrication, test and finally launch.
The launch date scheduled for Proba-3 is 2020. The venture will help solar research by providing scientists with long, uninterrupted, views of the sun’s tenuous outer atmosphere, the corona.
The corona is the region of the sun where space weather is generated. Giant gusts known as coronal mass ejections can endanger satellites and disrupt communication and navigational devices on earth.
This week’s total eclipse, which was witnessed across the US from the west coast to the eastern shores, lasted just 160 seconds. With Proba-3 artificial eclipses will be created lasting six hours. For this, two spacecraft will be used. One will contain the instruments, the second will block the light from the sun.
To maintain the eclipse the two craft must fly 150 metres or more apart yet maintain their alignment to within a millimetre.
As well as the scientific return, the ESA mission goal is to test whether such formation flying is possible. The technique is crucial for future projects like ESA’s laser interferometer space antenna, or LISA mission. The LISA venture will be the first space-based mission to search for gravitational waves, the recently detected ripples in space-time predicted by Albert Einstein about a century ago.
Formation flying requires the satellites to know precisely where they are in relation to one another. Hence the technique could also be used to allow spacecraft that are able to carry out repairs to find and rendezvous with stricken satellites and assist in orbit.
