Candidate Comet Landing Sites Identified
 
August 26, 2014:  The European Space Agency's Rosetta mission has chosen
five candidate landing sites on comet 67P/Churyumov-Gerasimenko for its
Philae lander. Philae's descent to the comet's nucleus, scheduled for this
November, will be the first such landing ever attempted.
 
http://tinyurl.com/q2qoopb
 
This annotated image depicts four of the five potential landing sites for
Rosetta's Philae lander.  Image credit: ESA/Rosetta/MPS for OSIRIS Team
MPS/UPD/LAM/IAA/SSO/INTA/UPM  Full image and caption.
 
"This is the first time landing sites on a comet have been
considered," said Stephan Ulamec, Philae Lander Manager at the German
Aerospace Center, Cologne, Germany. "The candidate sites that we want
to follow up for further analysis are thought to be technically feasible on
the basis of a preliminary analysis of flight dynamics and other key issues
- for example, they all provide at least six hours of daylight per comet
rotation and offer some flat terrain. Of course, every site has the
potential for unique scientific discoveries."
 
For each possible zone, important questions must be asked: Will the lander
be able to maintain regular communications with Rosetta? How common are
surface hazards such as large boulders, deep crevasses or steep slopes? Is
there sufficient illumination for scientific operations and enough sunlight
to recharge the lander's batteries beyond its initial 64-hour lifetime
without causing overheating?
 
The potential landing sites were assigned a letter from an original
pre-selection of 10 possible sites, which does not signify any ranking.
Three sites (B, I and J) are located on the smaller of the two lobes of the
comet and two sites (A and C) are located on the larger lobe.
 
[See above link]
 
This annotated image depicts two of the five potential landing sites for
Rosetta's Philae lander, including one ("C") not shown in the
image above. Image credit: ESA/Rosetta/MPS for OSIRIS Team
MPS/UPD/LAM/IAA/SSO/INTA/UPM  
"The process of selecting a landing site is extremely complex and
dynamic; as we get closer to the comet, we will see more and more details,
which will influence the final decision on where and when we can
land," said Fred Jansen, Rosetta's mission manager from the European
Space Agency's Science and Technology Centre in Noordwijk, The Netherlands.
"We had to complete our preliminary analysis on candidate sites very
quickly after arriving at the comet, and now we have just a few more weeks
to determine the primary site. The clock is ticking and we now have to meet
the challenge to pick the best possible landing site."
 
The next step in preparation for landing operations is a comprehensive
analysis of each of the candidate sites, to determine possible orbital and
operational strategies that could be used for Rosetta to deliver the lander
to any of them. At the same time, Rosetta will move to within 31 miles (50
kilometers) of the comet, allowing a more detailed study of the proposed
landing sites. By September 14, the five candidate sites will have been
assessed and ranked, leading to the selection of a primary landing site. A
fully detailed strategy for the landing operations at the selected site
will be developed, along with a backup.
 
The landing of Philae is expected to take place in mid-November when the
comet is about 280 million miles (450 million kilometers) from the sun.
This will be before activity on the comet reaches levels that might
jeopardize the safe and accurate deployment of Philae to the comet's
surface, and before surface material is modified by this cometary activity.
 
Rosetta is an international mission spearheaded by the European Space
Agency with support and instruments provided by NASA.
 
For more information on the U.S. instruments aboard Rosetta, visit:
http://rosetta.jpl.nasa.gov.  The ESA's Rosetta home page is at
http://www.esa.int/rosetta .
 
Credits:
Production editor: Dr. Tony Phillips | Credit: Science{at}NASA
 
More information:
 
Choosing the right landing site is a complex process. It must balance the
technical needs of the orbiter and lander during all phases of the
separation, descent and landing, and during operations on the surface, with
the scientific requirements of the 10 instruments on board Philae. A key
issue is that uncertainties in navigating the orbiter close to the comet
mean that it is possible to specify any given landing zone only in terms of
an ellipse - covering up to six-tenths of a square mile (one square
kilometer) - within which Philae might land.
 
Launched in March 2004, Rosetta was reactivated in January 2014 after a
record 957 days in hibernation. Composed of an orbiter and lander,
Rosetta's objectives since arriving at comet 67P/Churyumov-Gerasimenko
earlier this month are to study the celestial object up close in
unprecedented detail, prepare for landing a probe on the comet's nucleus in
November, and track its changes through 2015, as it sweeps past the sun.
 
Comets are time capsules containing primitive material left over from the
epoch when the sun and its planets formed. Rosetta's lander will obtain the
first images taken from a comet's surface and will provide comprehensive
analysis of the comet's possible primordial composition by drilling into
the surface. Rosetta also will be the first spacecraft to witness at close
proximity how a comet changes as it is subjected to the increasing
intensity of the sun's radiation. Observations will help scientists learn
more about the origin and evolution of our solar system and the role comets
may have played in seeding Earth with water, and perhaps even life.
 
The scientific imaging system, OSIRIS, was built by a consortium led by the
Max Planck Institute for Solar System Research (Germany) in collaboration
with Center of Studies and Activities for Space, University of Padua
(Italy), the Astrophysical Laboratory of Marseille (France), the Institute
of Astrophysics of Andalusia, CSIC (Spain), the Scientific Support Office
of the European Space Agency (Netherlands), the National Institute for
Aerospace Technology (Spain), the Technical University of Madrid (Spain),
the Department of Physics and Astronomy of Uppsala University (Sweden) and
the Institute of Computer and Network Engineering of the TU Braunschweig
(Germany). OSIRIS was financially supported by the national funding
agencies of Germany (DLR), France (CNES), Italy (ASI), Spain, and Sweden
and the ESA Technical Directorate.
 
Rosetta is an ESA mission with contributions from its member states and
NASA. Rosetta's Philae lander is provided by a consortium led by the German
Aerospace Center, Cologne; Max Planck Institute for Solar System Research,
Gottingen; French National Space Agency, Paris; and the Italian Space
Agency, Rome. NASA's Jet Propulsion Laboratory in Pasadena, California, a
division of the California Institute of Technology, manages the U.S.
participation in the Rosetta mission for NASA's Science Mission Directorate
in Washington.
 
 
Regards,
 
Roger

--- D'Bridge 3.99