On May 2009 the III Solar Orbiter Workshop was held in Sorrento, Italy. The decision of NASA to drop the Sentinels Mission had a stong impact on the SO orbiter mission objectives. Infact they heve been previously re-defined in the context of the HELEX mission (SO + Sentinels), with the intent of exploiting all the synergies among the remote sensing packages onboard SO and the in-situ packages onboar SO itself and the four sentinels.


At the same time NASA decided to push forward the Solar Probe Plus mission, a new mission concept based on the old Solar Probe mission, that basically will fly less closer to the Sun (about 12 solar radii instead of 4) but will spend considerably more time within 30 solar radii from the Sun's surface.
Despite the development of two missions will proceed separately, their specific orbit and peculiarity (out of ecliptic orbit and closeness to the Sun for SO and SPP respectively) have stimulated scientist to search for synergies between the two missions. The meeting developed along two main streams. From the one hand there was the clear need to re-establish the importance of the SO mission on its own, hence re-assessing the SO science objectives and reporting about the advances in the instruments development. From the other hand, the possiblilty of combining the SO in-situ and remote sensing packages with those of SPP (alignment and quadrature observations, multi-point insitu measuremnts) brought fresh and stimulating ideas that in the future could lead to a real breakthrou in solar and heliospheric science.
More informations about the meeting, including presentations, can be found here.