ESA Science & Technology - LOI results

Into a mass of 180 kilograms, the scientists want to accommodate a set of in-situ and a set of remote sensing instruments. The in-situ instruments consist of detectors for observing particles and events in the immediate vicinity of the spacecraft: the charged particles and magnetic fields of the solar wind, radio and magnetic waves in the solar wind, and energetic charged particles flung out by the Sun.

The remote sensing instruments will observe the Sun's surface and atmosphere. The gas of the atmosphere is best seen by its strong emissions of short-wavelength ultraviolet rays. Tuned to these will be a full-Sun and high-resolution imager and a high-resolution spectrometer. The outer atmosphere will be revealed by ultraviolet and visible-light coronagraphs that blot out the bright disc of the Sun. To examine the surface by visible light, and measure local magnetic fields, Solar Orbiter will carry a high-resolution telescope and magnetograph.

AO and Call for Letters of Intent

An initial call for letters of intent was released in July 2006, followed by the Announcement of Opportunity in October 2007.

Responses to Call

The responses to the call are split into two categories: In-situ (measuring the environment along the spacecraft orbit) and Remote Sensing (observing the Sun).

The responses to the call for letters of intent are listed in the following table.