Scientific Results from Lutetia flyby

Asteroid 21 Lutetia was approached by the ESA's Rosetta spacecraft on 10 July 2010. During this flyby, spectacular images were taken by Rosetta's OSIRIS cameras revealing the richness of the geological processes of this asteroid as well as to determine its density, 3.4±0.3 g/cm³, one of the highest measured for an asteroid. These observations lead to believe that asteroid 21 Lutetia is probably a primeval planetesimal, relic form the initial Solar System, which didn't breaksince its formation about 4 billion years ago, contrarilly to most of other asteroids (>95%). The LAM (Laboratoire d'Astrophysique de Marseille – CNRS/Université de Provence), as part of OSIRIS scientific team, was particularly involved in this exceptional result, published in "Science".

Other scientific results obtained from different instruments of Rosetta during the same flyby were published in other "Science" articles on October 28, 2011.

Images of Asteroid 21 Lutetia: A Remnant Planetesimal from the Early Solar System

The Surface Composition and Temperature of Asteroid 21 Lutetia As Observed by Rosetta/VIRTIS

Asteroid 21 Lutetia: Low Mass, High Density

For more information about these results, see the ESA's website

ROSETTA enters hibernation in deep space

After a series of maneuvers in January and February that placed Rosetta on the right trajectory to intercept the comet in 2014, today, 8 of June 2011, the link with the probe has been turned off for a hibernation period of more than 30 months: this morning at 07:30 UTC Rosetta was spun up to stabilise its attitude so that solar panels would face the Sun during its long visit of the Jupiter neighbourhood. Indeed if Rosetta will sleep it will keep on controlling power and temperature by its own.
The hibernation exit is planned on January 23, 2014.

Read more about it on ESA's website

Latest news from ROSETTA
The test just before hibernation was requested to prove the new version of the main CDMS flight software V8.14 is able to manage the complex activities of the Separation-Descent-Landing phase that will be run in 2014: a 30 minutes landing trajectory was chosen and simulated comprising 6 instruments working consecutively or in parallel. Moreover the last mode never tested yet of the Ptolemy instrument was performed as well as new interference tests between Sesame and Consert instruments. All these operations went flawlessly, all data were correctly stored in the different memories and downloaded to the Earth. Perturbations of Consert and Sesame on eachother are confirmed and will prevent the 2 instruments to work simultaneously. In summary Philae is ready to take the 3 years sleep (full 2011 to 2013) of hibernation phase.

Ground means, LCC and SONC, behaved perfectly too. But they will not hibernate at all in the coming years. On the contrary the 2 centers will be refurbished to be able to run the very complicated ground and flight operations of the comet phase. Indeed we have to face a landing on a totally unknown body in a very far corner of the solar system.

An example of the pictures taken at 3.7 AU (555 millions of km) from the Sun by the CIVA instrument of Philae (copyright: ESA/Philae/CIVA). The first left and the last right show the 2 Rosetta dark orbiter solar panels.

Lutetia fly-by, on saturday July 10th, was fully successful
The entry in "asteroid fly-by" mode, time of the asteroid closest approach, as well as the end of the period without data transmission run exactly as planned. the Osiris cameras, WAC (wide field) and NAC (high resolution) also, functioned perfectly. Which resulted in these magnificient images:

The Osiris images enable to see a little more than 50 % of the asteroid surface. The visible side is 126 km long and 88 km wide. It is a very craterized asteroid, as many of them, but with some clean surfaces or with few craters, which indicates "young" surfaces (compared to the solar system, but none the less several millions of years old).
Another preliminary result, no magnetic field, seams to indicate that contrarily to what most of scientists thought, the asteroid is not metallic. But it remains to be confirmed.
A large number of other results can't be obtained in realtime. Several months, if not several years, will be necessary to study all the collected data.

Rosetta evening at the Cité de l'Espace, in Toulouse
After the fly-by of asteroid Lutetia by Rosetta, results and comments about the Rosetta mission objectives with: Philippe Gaudon, CNES project manager for the French contributions to Rosetta; Laurent Jorda, Astronomer at Marseille Provence Astronomy Observatory, French scientist specialist of Osiris Camera that will image Lutetia; Sylvestre Maurice, Astrophysicist at CESR; Lionel D'Uston, CNRS reseach Director.
In partnership with the CESR, Marseille Astronomy Observatory and EADS Astrium.
Free exhibition, registery advised at standard@cite-espace.com
Live broadcast on the space news website www.enjoyspace.com

Fly-by of asteroid Lutetia by Rosetta at 17h 45 local time at an altitude of 3000 km
This fly-by will take place at 457 millions of kilometres from our planet and will enable an estimation of its main characteristics.
Lutetia is about 100 km in diameter, thus superb images are expected. In addition to most of the orbiter's instruments, 3 of Philae instruments will be switched on (1 magnetometer and 2 spectrometers if an exosphere is present to "sniff").

Payload Check-Out n°12
The main objective is to test a new version of the main CDMS flight software dedicated to the comet phase. The basic functions of memory storage and communication with the orbiter will be checked. It will be an opportunity to change or refresh flight software of instruments, revalidate their nominal functioning and prepare with Ptolemy the coming Lutetia fly-by on July 10, 17h45 local time.