Europe's comet-chasing Rosetta mission

 A timeline of Europe's Rosetta mission, which marked the end of a chapter Friday when ground controllers said they would stop trying to contact robot lab Philae on the surface of comet 67P/Churyumov-Gerasimenko.

- March 2, 2004: 

Rosetta, with Philae riding piggyback, is launched on an Ariane 5 rocket from the European Space Agency's base in Kourou, French Guiana.

- March 2005: 

Rosetta flies past Earth, using the planet's gravity as a slingshot to boost its speed. It zips by Mars in 2007 and twice more by Earth, in 2007 and 2009, to accelerate more.

- June 2011 to January 2014: 
At its maximum distance -- about 800 million kilometres (500 million miles) -- from the Sun and a billion km from home, Rosetta hibernates to conserve energy.

- August 6, 2014: 

Rosetta arrives at comet 67P/Churyumov-Gerasimenko, and goes into its orbit. It has 11 onboard instruments: cameras, radar, microwave, infrared and other sensors to analyse the comet surface and gases escaping from it.

- November 12, 2014: 

Rosetta sends down Philae, a 100-kilogram (220-pound) lab equipped with 10 instruments. After bouncing several times, Philae ends in a ditch, shadowed from the Sun's battery-replenishing rays.

- November 15, 2014: 
Philae's stored battery power runs out after about 60 hours of work. It sends home reams of data before going into standby mode. 

- June 13, 2015:

As 67P nears the Sun, Philae's batteries are recharged, it emerges from hibernation and sends home a two-minute message.

- July 9, 2015:

Philae goes into "silent mode" after eight intermittent communications with Earth.

- August 13, 2015:

67P comes within 186 million km of the Sun, its closest distance to our star, before shooting off again to restart its 6.5-year orbit.

- January 2016: 

Ground controllers command Philae to spin up its flywheel in the hope it would shake dust from its solar panels and better align itself with the Sun to charge its battery and re-establish contact. Philae did not send any message back.

Looking ahead:

- September 2016: 

Projected end of the mission, with Rosetta to be reunited with Philae on the comet surface in September.