Sunjammer, NASA’s next solar sail experiment.
Though the article headline focuses on the addition of space weather instruments to this solar sail, the article says very little about those instruments. One, Swan, is described as a “wind instrument”, which probably means it would study the solar wind. The other instrument would study the Earth’s magnetic field. Both instruments are needed to track the effect of the Sun on local space weather, since the one satellite we have to do this, Ace, is now more than a decade past its expiration date.