|| Home. | Universe Galaxies And Stars Archives. | |
|| Universe | Big Bang | Galaxies | Stars | Solar System | Planets | Hubble Telescope | NASA | Search Engine ||
Rosetta is an ESA spacecraft mission to investigate comet Churyumov-Gerasimenko.
Rosetta spacecraft is a European Space Agency-led robotic mission. Rosetta spacecraft was launched in 2004. Rosetta spacecraft is intended to study the comet 67P/Churyumov-Gerasimenko. Rosetta spacecraft consists of two main elements: the Rosetta space probe and the Philae lander. The probe is named after the Rosetta Stone, as it is hoped the mission will help unlock the secrets of how our solar system looked before planets formed. The lander is named after the Nile island Philae where an obelisk was found that helped decipher the Rosetta Stone.
Overview of Rosetta spacecraft.
During the 1986 apparition of the Comet Halley, a number of international space probes were sent to explore the cometary system, most prominent among them being ESA's highly successful Giotto. After the probes returned a treasure-trove of valuable scientific information it was becoming obvious that follow-ons were needed that would shed more light on the complex cometary composition and resolve the newly opened questions.
Both NASA and ESA started cooperatively developing new probes, the NASA led effort was the Comet Rendezvous Asteroid Flyby or CRAF mission, the follow-on Comet Nucleus Sample Return or CNSR mission was to be an ESA led effort, both missions were to share the common Mariner Mark II design, thus minimizing costs. In 1992, after NASA axed CRAF because of budgetary limitations, ESA decided on developing the spacecraft by themselves. By 1993 it was evident that the ambitious sample return mission was unfeasible with the existing ESA budget, so instead the mission was redesigned, with the final flight plan resembling the canceled CRAF mission, an asteroid flyby followed by a comet rendezvous with in-situ examination, including a lander.
Rosetta was built in a clean room according to COSPAR rules, but "Sterilisation [was] generally not crucial since comets are usually regarded as objects where you can find prebiotic molecules, that is, molecules that are precursors of life, but not living microorganisms," according to Gerhard Schwehm, Rosetta's Project Scientist.
It was set to be launched on January 12, 2003 to rendezvous with the comet 46P/Wirtanen in 2011.
However this plan was abandoned after an Ariane 5 failure on December 11, 2002. A new plan was formed to target the comet 67P/Churyumov-Gerasimenko with launch on February 26, 2004 and rendezvous in 2014. The larger mass and the resulting increased impact velocity made modification of the landing gear necessary. After two cancelled launch attempts, Rosetta was launched on March 2, 2004 at 7:17 GMT. Besides the changes made to launch time and target, the mission profile remains almost identical.
On 25 February 2007, the Rosetta craft was scheduled for a low-altitude bypass of Mars, as this was needed to correct the trajectory after the first lauch in 2003 was delayed by one year. This was not without risk, as the estimated altitude of the flyover manoeuvre was a mere 250 km (155 miles). Furthermore, the solar panels could not be used as the craft was at the far side of Mars, where it would not receive any solar light for 15 minutes, causing a dangerous shortage of power. The craft was therefore put into standby mode, with no possibility to communicate, flying on batteries that were originally not designed for this task. This Mars manouvre was therefore nicknamed "The Billion Dollar Gamble". Fortunately, the flyby was successful at 03:15 CET and the mission now continues.
In May 2014, the Rosetta craft will enter a very slow orbit around the comet and gradually slow down in preparation for releasing a lander that will make contact with the comet itself. The lander, named "Philae", will approach 67P/Churyumov-Gerasimenko at relative speed around 1 m/s and on contact with the surface, two harpoons will be fired into the comet to prevent the lander from bouncing off. Additional drills are used to further secure the lander on the comet.
Once attached to the comet, expected to take place in November 2014, the lander will begin its science mission:
The exact surface layout of the comet is currently unknown and the orbiter has been built to map this before detaching the lander. It is anticipated that a suitable landing site can be found, although few specific details exist regarding the surface.
Mission timeline of Rosetta spacecraft.
Instruments on board Rosetta spacecraft.
The spectroscopical investigation of the core is done by four instruments:
Rosetta spacecraft: Gas and Particles.
Rosetta spacecraft: Solarwind interaction.
Major events and discoveries by Rosetta spacecraft.
Go To Print Article
Universe - Galaxies and Stars: Links and Contacts
|| GNU License | Contact | Copyright | WebMaster | Terms | Disclaimer | Top Of Page. ||