Rosetta (spacecraft) in the context of "Comet nucleus"

M-type (metallic-type, aka M-class) asteroids are a spectral class of asteroids which appear to contain higher concentrations of metal phases (e.g. iron-nickel) than other asteroid classes, and are widely thought to be the source of iron meteorites.

The European Space Operations Centre (ESOC) serves as the main mission control centre for the European Space Agency (ESA) and is located in Darmstadt, Germany. ESOC's primary function is the operation of uncrewed spacecraft on behalf of ESA and the launch and early orbit phases (LEOP) of ESA and third-party missions. The Centre is also responsible for a range of operations-related activities within ESA and in cooperation with ESA's industry and international partners, including ground systems engineering, software development, flight dynamics and navigation, development of mission control tools and techniques and space debris studies.

ESOC's current major activities comprise operating planetary and solar missions, such as Mars Express and the Trace Gas Orbiter, astronomy & fundamental physics missions, such as Gaia and XMM Newton, and Earth observation missions such as CryoSat2 and Swarm.

Philae (/ˈfaɪliː/ or /ˈfiːleɪ/) was a robotic European Space Agency lander that accompanied the Rosetta spacecraft until it separated to land on comet 67P/Churyumov–Gerasimenko, ten years and eight months after departing Earth. On 12 November 2014, Philae touched down on the comet, but it bounced when its anchoring harpoons failed to deploy and a thruster designed to hold the probe to the surface did not fire. After bouncing off the surface twice, Philae achieved the first-ever "soft" (nondestructive) landing on a comet nucleus, although the lander's final, uncontrolled touchdown left it in a non-optimal location and orientation.

Despite the landing problems, the probe's instruments obtained the first images from a comet's surface. Several of the instruments on Philae made the first in-situ analysis of a comet nucleus, sending back data regarding the composition of the surface and outgassing from the subsurface. In October 2020, scientific journal Nature published an article revealing what Philae had discovered while it was operational on the surface of 67P/Churyumov–Gerasimenko.

67P/Churyumov–Gerasimenko (abbreviated as 67P or 67P/C–G) is a Jupiter-family comet. It is originally from the Kuiper belt and has an orbital period of 6.45 years as of 2012, a rotation period of approximately 12.4 hours, and a maximum velocity of 135,000 km/h (38 km/s; 84,000 mph). Churyumov–Gerasimenko is approximately 4.3 by 4.1 km (2.7 by 2.5 mi) at its longest and widest dimensions. It was first observed on photographic plates in 1969 by Soviet astronomers Klim Ivanovych Churyumov and Svetlana Ivanovna Gerasimenko, after whom it is named. It most recently came to perihelion (closest approach to the Sun) on 2 November 2021, and will next come to perihelion on 9 April 2028.

Churyumov–Gerasimenko was the destination of the European Space Agency's Rosetta mission, launched on 2 March 2004. Rosetta rendezvoused with Churyumov–Gerasimenko on 6 August 2014 and entered orbit on 10 September 2014. Rosetta's lander, Philae, landed on the comet's surface on 12 November 2014, becoming the first spacecraft to land on a comet nucleus. On 30 September 2016, the Rosetta spacecraft ended its mission by landing on the comet in its Ma'at region.

The Herschel Space Observatory was a space observatory built and operated by the European Space Agency (ESA). It was active from 2009 to 2013, and was the largest infrared telescope ever launched until the launch of the James Webb Space Telescope in 2021. Herschel carries a 3.5-metre (11.5 ft) mirror and instruments sensitive to the far infrared and submillimetre wavebands (55–672 μm). Herschel was the fourth and final cornerstone mission in the Horizon 2000 programme, following SOHO, Cluster II, XMM-Newton and Rosetta.

The observatory was carried into orbit by an Ariane 5 in May 2009, reaching the second Lagrangian point (L2) of the Earth–Sun system, 1,500,000 kilometres (930,000 mi) from Earth, about two months later. Herschel is named after Sir William Herschel, the discoverer of the infrared spectrum and planet Uranus, and his sister and collaborator Caroline Herschel.

Hibernation of spacecraft is an operating mode used when regular operations are suspended for an extended period of time but restarting is expected (unlike termination). On long duration and deep space missions it saves power or other limited resources and extends mission life. The term is substantially similar to the hibernation mode used in computer power saving.

• Rosetta, a mission to study comet 67P/Churyumov–Gerasimenko (67P), was placed into hibernation for 31 months to conserve its limited resources when it ventured near the orbit of Jupiter while en route to its rendezvous.
• The New Horizons mission entered hibernation mode many times on its way to Pluto and then again while en route to the Kuiper belt object 486958 Arrokoth. Its hibernation mode provides some amount of health and status monitoring and occasional wake-ups to check and calibrate instruments.
• NASA's Wide-field Infrared Survey Explorer mission, originally operated by the agency's astrophysics division for an infrared all-sky survey, was placed into hibernation in 2011 and then reawakened in 2013 to conduct an asteroid survey by the planetary science division.

The Science Programme of the European Space Agency is a long-term programme of space science and space exploration missions. Managed by the agency's Directorate of Science, The programme funds the development, launch, and operation of missions led by European space agencies and institutions through generational campaigns. Horizon 2000, the programme's first campaign, facilitated the development of eight missions between 1985 and 1995 including four "cornerstone missions" – SOHO and Cluster II, XMM-Newton, Rosetta, and Herschel. Horizon 2000 Plus, the programme's second campaign, facilitated the development of Gaia, LISA Pathfinder, and BepiColombo between 1995 and 2005. The programme's current campaign since 2005, Cosmic Vision, has so far funded the development of ten missions including three flagship missions, JUICE, Athena, and LISA. The programme's upcoming fourth campaign, Voyage 2050, is currently being drafted. Collaboration with agencies and institutions outside of Europe occasionally occur in the Science Programme, including a collaboration with NASA on Cassini–Huygens and the CNSA on SMILE.