Rosetta made history when the craft made its rendezvous with comet 67P/Churyumov-Gerasimenko in 2014 and deployed the Philae lander, with the goal of performing both remote sensing and in situ measurements. RHEA staff are involved in the development, maintenance and support of the Rosetta archives.

Rosetta mission timescale

Mission launch: 2 March 2004
End of operations: 30 September 2016

About the Rosetta mission

Rosetta was a European Space Agency (ESA) cornerstone mission initially set for a rendezvous with comet 46 P/Wirtanen. The initial launch date was postponed, so a new target was selected: comet 67P/Churyumov-Gerasimenko.

During the long journey towards 67P, Rosetta performed observations on two comets in the asteroid belt, Šteins and Lutetia, in September 2008 and July 2010.

At last, in September 2014, after one month of complex manoeuvres and more than 10 years after launch, Rosetta started orbiting 67P.

Philae and Rosetta land on comet 67P

In November 2014, after extensive testing, the Philae lander was released onto the comet’s surface. Unfortunately, due to a problem with one of the thrusters and the harpoon system that was due to anchor the lander to the comet, Philae bounced twice, leaving it in shadow. This cut its operation short, as once the batteries supplying power to all the instruments were exhausted, the instruments stopped working.

This was a rather sad end to such an exciting endeavour with the lander. However, Rosetta stayed in orbit around 67P and all its instruments worked perfectly. That enabled two more years of data acquisition until the end of the mission in September 2016, when Rosetta was sent on a controlled descent onto the surface of the comet.

Rosetta continued acquiring data until the last moment. The images acquired by the OSIRIS camera during the descent were transmitted to ESA’s European Space Operations Centre (ESOC) in Darmstadt, Germany, providing many close-ups of interesting features on the surface of the comet.

An outburst from Comet 67P/Churyumov–Gerasimenko captured by Rosetta’s OSIRIS narrow-angle camera. Image copyright: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
An outburst from Comet 67P/Churyumov–Gerasimenko captured by Rosetta’s OSIRIS narrow-angle camera. © ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Rosetta’s main technical achievements

Determining the path of a satellite from launch to final orbit is an extremely complicated task that needs to consider the limits to the volume of fuel that can be carried on board. For missions like Rosetta, trajectories need to be optimized in order to take advantage of the help that can be provided by gravity.

In the case of Rosetta, its flight made use of the gravity of the Earth and Mars in order to reach 67P, using three Earth flybys and one via Mars.

The Mars flyby on 27 February 2007 was particularly critical due to:

  • its low altitude – a mere 250km from the surface
  • being in shadow, making it impossible to recharge the batteries for all systems on board.

The fact that the spacecraft emerged from those 15 minutes of darkness with all systems in perfect condition is a tribute to the amazing capabilities of the engineers and scientists responsible for operating Rosetta.

See images of Rosetta’s flybys of Earth, Mars and asteroids

Rosetta’s main scientific achievements

Just as the Rosetta stone played a crucial role in helping to decipher Egyptian hieroglyphs, the Rosetta spacecraft will help us unravel the mysteries of the formation of the solar system.

Comets are made of the primordial material that has given rise to most of the solar system. Understanding its composition will help scientists determine how the solar system has formed.

Some exciting discoveries have already been made. It has long been assumed that water was brought to Earth by comets crashing onto the surface. However, it turns out that water molecules detected by Rosetta on the surface of 67P are mostly made with a type of hydrogen that is different from the most common type found on Earth. If 67P is truly representative of the comets that bombarded Earth during its formation, then water must have been brought to Earth by a different mechanism.

This is a truly exciting discovery and raises important questions regarding the origin of the Earth and the solar system.

Overall, in situ data acquisition was cut short due to the loss of Philae, but the amount of data acquired by the Rosetta mission will keep scientists busy for many years.

Strange but true

Unexpectedly, Rosetta measured an oscillating magnetic field on the surface of 67P. The field is most likely to be a result of the interaction of the solar wind with the surface of the comet and not generated by the core of 67P.

Although a completely natural phenomenon, this effect has been described as a song. German composer Manuel Senfft created an artistic rendition from the data acquired by the magnetometers on board Rosetta that, despite being a piece of ‘natural’ art, has been compared to the piece Continuum for harpsichord by Hungarian avant-garde composer György Ligeti.

Read more about ‘the singing comet’.

How RHEA is contributing to the Rosetta mission

RHEA MOIS software was used for Rosetta mission procedure preparation and management.

RHEA staff are now involved in the development, maintenance and support of the Rosetta archives, part of the Planetary Science Archive (PSA) at the ESAC Science Data Centre (ESDC).

Although this behind the scenes work does not get much visibility, it is absolutely essential as it provides the international scientific community with long-term access to the data, thus fostering scientific discovery. RHEA is one of the main contributors to the development and support of the ESDC.


Main image: © ESA/ATG medialab

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