Sean Solomon Biography

MESSENGER launches to begin a complex seven-year journey that will culminate in the first orbital mission around Mercury.

MESSENGER flies past Earth for a gravity assist and calibrates its instruments while continuing toward Mercury.

MESSENGER completes its first Venus gravity assist, reducing orbital energy on the long route toward Mercury.

MESSENGER makes its second Venus flyby, using the encounter to reshape its orbit for later Mercury approaches.

MESSENGER completes its first Mercury flyby and returns the first close-up observations of the planet in more than thirty years.

MESSENGER images provide strong evidence for ancient volcanic activity on Mercury, including identified volcanic vents.

MESSENGER completes a second close flyby of Mercury and adjusts its solar orbit for eventual capture by the planet.

MESSENGER makes its third and final Mercury flyby before orbit insertion, further matching the spacecraft's path to Mercury's orbit.

During its cruise to Mercury orbit, MESSENGER photographs the planets to assemble a wide-angle portrait of the Solar System.

MESSENGER results establish that Mercury's internal magnetic field is about one hundred times weaker than Earth's field.

MESSENGER fires its main engine and becomes the first spacecraft to enter orbit around Mercury.

MESSENGER begins its primary year-long orbital science campaign to map Mercury and study its composition, magnetic field and environment.

MESSENGER begins its first extended mission after completing the primary year of orbital observations.

Mission controllers reduce MESSENGER's orbital period to about eight hours, increasing the number of close Mercury passes each day.

MESSENGER begins a second extended phase of Mercury observations, allowing progressively lower-altitude measurements.

MESSENGER begins increasingly low-altitude Mercury observations as its orbit evolves during the extended mission.

MESSENGER conducts an exceptionally low-altitude final campaign, obtaining measurements from only tens of kilometres above Mercury.

MESSENGER ends its mission by impacting Mercury after completing 4,105 orbits and transforming knowledge of the planet.

A post-mission data release provides the first global topographic model of Mercury and expands the lasting scientific archive from MESSENGER.