The STEREO mission launched in 2006 and provided us with a pair of Sun orbiting satellites in order to observe the farside of the Sun.. For many years both STEREO-Ahead and STEREO-Behind did just that and made tracking sunspot regions easier once they rotated out of direct view. In 2014, the STEREO-Behind spacecraft suffered a major malfunction and no further imagery was available from that satellite. This left us with the STEREO-Ahead spacecraft which continues to beam back images to this day. For many years the section of the Sun approaching the east limb was still observable and gave us a great deal of warning on approaching active regions. Due to its continuing orbit around the Sun, STEREO-A caught up with Earth and will begin to observe the farside beyond the west limb.
In the future, imagery courtesy of STEREO-Ahead should still be available, however a focus will be put on a technique called Time-Distance Helioseismology in order to track potential farside active regions.
