|Mission type||Comet orbiter/lander|
|Mission duration||Final: 12 years, 6 months, 28 days|
|Launch mass||Orbiter: 2,900 kg (6,400 lb)|
Lander: 100 kg (220 lb)
|Dry mass||Orbiter: 1,230 kg (2,710 lb)|
|Payload mass||Orbiter: 165 kg (364 lb)|
Lander: 27 kg (60 lb)
|Dimensions||2.8 × 2.1 × 2 m (9.2 × 6.9 × 6.6 ft)|
|Power||850 watts at 3.4 AU|
|Start of mission|
|Launch date||2 March 2004, 07:17:51UTC|
|Rocket||Ariane 5G+ V-158|
|Launch site||Kourou ELA-3|
|End of mission|
|Last contact||30 September 2016, 10:39:28UTC SCET|
|Landing site||Sais, Ma'at region |
2 years, 55 days of operations at the comet
|Flyby of Earth|
|Closest approach||4 March 2005|
|Distance||1,954 km (1,214 mi)|
|Flyby of Mars|
|Closest approach||25 February 2007|
|Distance||250 km (160 mi)|
|Flyby of Earth|
|Closest approach||13 November 2007|
|Distance||5,700 km (3,500 mi)|
|Flyby of 2867 Šteins|
|Closest approach||5 September 2008|
|Distance||800 km (500 mi)|
|Flyby of Earth|
|Closest approach||12 November 2009|
|Distance||2,481 km (1,542 mi)|
|Flyby of 21 Lutetia|
|Closest approach||10 July 2010|
|Distance||3,162 km (1,965 mi)|
|Orbital insertion||6 August 2014, 09:06 UTC|
|Periapsis altitude||29 km (18 mi)|
|Band||S band (low gain antenna)|
X band (high gain antenna)
|Bandwidth||from 7.8 bit/s (S band)|
up to 91 kbit/s (X band)
ESA Solar System insignia for Rosetta
Rosetta was a space probe built by the European Space Agency launched on 2 March 2004. Along with Philae, its lander module, Rosetta performed a detailed study of comet 67P/Churyumov–Gerasimenko (67P). During its journey to the comet, the spacecraft performed flybys of Earth, Mars, and the asteroids 21 Lutetia and 2867 Šteins. It was launched as the third cornerstone mission of the ESA's Horizon 2000 programme, after SOHO / Cluster and XMM-Newton.
On 6 August 2014, the spacecraft reached the comet and performed a series of manoeuvres to eventually orbit the comet at distances of 30 to 10 kilometres (19 to 6 mi). On 12 November, its lander module Philae performed the first successful landing on a comet, though its battery power ran out two days later. Communications with Philae were briefly restored in June and July 2015, but due to diminishing solar power, Rosetta's communications module with the lander was turned off on 27 July 2016. On 30 September 2016, the Rosetta spacecraft ended its mission by hard-landing on the comet in its Ma'at region.
The probe was named after the Rosetta Stone, a stele of Egyptian origin featuring a decree in three scripts. The lander was named after the Philae obelisk, which bears a bilingual Greek and Egyptian hieroglyphic inscription.
Rosetta was launched on 2 March 2004 from the Guiana Space Centre in Kourou, French Guiana, on an Ariane 5 rocket and reached Comet Churyumov–Gerasimenko on 7 May 2014. It performed a series of manoeuvres to enter orbit between then and 6 August 2014, when it became the first spacecraft to orbit a comet. (Previous missions had conducted successful flybys of seven other comets.) It was one of ESA's Horizon 2000 cornerstone missions. The spacecraft consisted of the Rosetta orbiter, which featured 12 instruments, and the Philae lander, with nine additional instruments. The Rosetta mission orbited Comet Churyumov–Gerasimenko for 17 months and was designed to complete the most detailed study of a comet ever attempted. The spacecraft was controlled from the European Space Operations Centre (ESOC), in Darmstadt, Germany. The planning for the operation of the scientific payload, together with the data retrieval, calibration, archiving and distribution, was performed from the European Space Astronomy Centre (ESAC), in Villanueva de la Cañada, near Madrid, Spain. It has been estimated that in the decade preceding 2014, some 2,000 people assisted in the mission in some capacity.
In 2007, Rosetta made a Mars gravity assist (flyby) on its way to Comet Churyumov–Gerasimenko. The spacecraft also performed two asteroid flybys. The craft completed its flyby of asteroid 2867 Šteins in September 2008 and of 21 Lutetia in July 2010. Later, on 20 January 2014, Rosetta was taken out of a 31-month hibernation mode as it approached Comet Churyumov–Gerasimenko.
Rosetta's Philae lander successfully made the first soft landing on a comet nucleus when it touched down on Comet Churyumov–Gerasimenko on 12 November 2014. On 5 September 2016, ESA announced that the lander was discovered by the narrow-angle camera aboard Rosetta as the orbiter made a low, 2.7 km (1.7 mi) pass over the comet. The lander sits on its side wedged into a dark crevice of the comet, explaining the lack of electrical power to establish proper communication with the orbiter.
During the 1986 approach of Halley's Comet, international space probes were sent to explore the comet, most prominent among them being ESA's Giotto. After the probes returned valuable scientific information, it became obvious that follow-ons were needed that would shed more light on cometary composition and answer new questions.
Both ESA and NASA started cooperatively developing new probes. The NASA project was the Comet Rendezvous Asteroid Flyby (CRAF) mission. The ESA project was the follow-on Comet Nucleus Sample Return (CNSR) mission. Both missions were to share the Mariner