Rosetta (spacecraft)


Rosetta spacecraft
Artist's illustration of Rosetta
Mission typeComet orbiter/lander
COSPAR ID2004-006A
SATCAT no.28169
Mission durationFinal: 12 years, 6 months, 28 days
Spacecraft properties
Launch massOrbiter: 2,900 kg (6,400 lb)
Lander: 100 kg (220 lb)
Dry massOrbiter: 1,230 kg (2,710 lb)
Payload massOrbiter: 165 kg (364 lb)
Lander: 27 kg (60 lb)
Dimensions2.8 × 2.1 × 2 m (9.2 × 6.9 × 6.6 ft)
Power850 watts at 3.4 AU[1]
Start of mission
Launch date2 March 2004, 07:17:51 (2004-03-02UTC07:17:51) UTC[2]
RocketAriane 5G+ V-158
Launch siteKourou ELA-3
End of mission
Last contact30 September 2016, 10:39:28 (2016-09-30UTC10:39:29) UTC SCET
Landing siteSais, Ma'at region[3]
2 years, 55 days of operations at the comet
Flyby of Earth
Closest approach4 March 2005
Distance1,954 km (1,214 mi)
Flyby of Mars
Closest approach25 February 2007
Distance250 km (160 mi)
Flyby of Earth
Closest approach13 November 2007
Distance5,700 km (3,500 mi)
Flyby of 2867 Šteins
Closest approach5 September 2008
Distance800 km (500 mi)
Flyby of Earth
Closest approach12 November 2009
Distance2,481 km (1,542 mi)
Flyby of 21 Lutetia
Closest approach10 July 2010
Distance3,162 km (1,965 mi)
67P/Churyumov–Gerasimenko orbiter
Orbital insertion6 August 2014, 09:06 UTC[4]
Orbital parameters
Periapsis altitude29 km (18 mi)[5]
BandS band (low gain antenna)
X band (high gain antenna)
Bandwidthfrom 7.8 bit/s (S band)[6]
up to 91 kbit/s (X band)[7]
Rosetta mission insignia
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).[8][9] During its journey to the comet, the spacecraft performed flybys of Earth, Mars, and the asteroids 21 Lutetia and 2867 Šteins.[10][11][12] 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).[13] On 12 November, its lander module Philae performed the first successful landing on a comet,[14] though its battery power ran out two days later.[15] 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.[16] On 30 September 2016, the Rosetta spacecraft ended its mission by hard-landing on the comet in its Ma'at region.[17][18]

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.

Mission overview

Comet Churyumov–Gerasimenko in September 2014 as imaged by Rosetta

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.[19] It performed a series of manoeuvres to enter orbit between then and 6 August 2014,[20] when it became the first spacecraft to orbit a comet.[21][19][22] (Previous missions had conducted successful flybys of seven other comets.)[23] It was one of ESA's Horizon 2000 cornerstone missions.[24] The spacecraft consisted of the Rosetta orbiter, which featured 12 instruments, and the Philae lander, with nine additional instruments.[25] 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.[26] 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.[27] It has been estimated that in the decade preceding 2014, some 2,000 people assisted in the mission in some capacity.[28]

In 2007, Rosetta made a Mars gravity assist (flyby) on its way to Comet Churyumov–Gerasimenko.[29] The spacecraft also performed two asteroid flybys.[30] The craft completed its flyby of asteroid 2867 Šteins in September 2008 and of 21 Lutetia in July 2010.[31] Later, on 20 January 2014, Rosetta was taken out of a 31-month hibernation mode as it approached Comet Churyumov–Gerasimenko.[32][33]

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.[34][35][36] 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.[37]



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.[38] 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.[39]

Both ESA and NASA started cooperatively developing new probes. The NASA project was the Comet Rendezvous Asteroid Flyby (CRAF) mission.[40] The ESA project was the follow-on Comet Nucleus Sample Return (CNSR) mission.[41] Both missions were to share the Mariner