In this erratum we acknowledge EASCO as one of the inspirational mission concepts that helped the development of our original mission concept OSCAR. It was brought to our attention that our original paper failed to acknowledge the mission concept EASCO, which was originally laid out in Gopalswamy et al. (2011). At the time we developed OSCAR, EASCO was one of the inspirational mission concepts on which we built our new and original concept of twin satellites leading and trailing the Earth with a separation angle of 68°. The omission of EASCO in our original paper was unintentional, and we wanted to acknowledge this important previous work in the present erratum.