ESA SATELLITES TO TEST RAZOR-SHARP FORMATION FLYING

Summary from the TLDR newsletter

The European Space Agency will launch a mission later this year to demonstrate precision formation flying in orbit to create artificial solar eclipses. The mission will involve a pair of spacecraft that will fly about 144 meters apart, with one spacecraft acting as a disc to block out the sun from the other spacecraft. This will allow the ESA to study the Sun's highly ionized atmosphere. The formation flying technology could be used for other future missions as well.