MESSENGER Says Its Final Farewell

Messenger sent this "family portrait" of the planets in the solar system, created from 34 images. (NASA)
Friday, May 01, 2015 

MESSENGER was the first spacecraft to orbit around Mercury. However on 30 April 2015, it also became the first spacecraft to make an impact crater on the rocky planet.

On 30 April, at 3:26 p.m., the MESSENGER spacecraft crashed into the surface of Mercury traveling at thousands of miles per hour after completing 4,104 orbits around Mercury during the past four years.

The probe, illustrated soaring above Mercury, went into orbit around the planet in March 2011, and ended it's journey on April 30, 2015, when it crash-landed into the rocky planet's surface. (NASA/JHU APL/CIW)

"We did not bring enough fuel to have any other type of possible outcome," said DTM Staff Scientist and MESSENGER Deputy Principal Investigator Larry Nittler to the BBC News' Katty Kay. "We had to be in a very elliptical orbit where we flew very close over one side of the planet [Mercury] and very far out the other way for various reasons but mostly to do with keeping our spacecraft cool and because of this it was not a very stable orbit. Gradually, the gravity of the Sun pulled us closer and closer to the planet and for most of the mission we were able to fire our engines periodically and boost ourselves up a little bit more."

That is until 30 April, when the "little spacecraft" finally ran out of thrust to keep itself in orbit.

"It's rather a quiet and solitary end to our mission," said former DTM Director and MESSENGER Principal Investigator Sean Solomon to NPR's Geoff Brumfield on MESSENGER's crash-landing.

NASA Spacecraft Crashes Into Mercury, Concluding 4-Year Study Of Planet
APRIL 30, 2015 4:27 PM ET by Geoff Brumfield, NPR

MESSENGER was launched from Earth in 2004, where it took more than six years to reach orbit around Mercury in March 2011. After traveling 8.73 billion miles and sending 289,265 images back to Earth, MESSENGER disappeared behind Mercury and left its own 52-foot-wide crater on the battered world just north of the Shakespeare basin for future probes to see from their orbits.

Written by Robin Dienel, 1 May 2015