THE ROSETTA
PROGRAM
D.Moura (CNES)
Content
The foundations
Some general aspects
Engineering
Development
Launch campaign
In flight operations
The foundations
The case for comets
• They very likely constitute the fossils bricks of the solar system
• They may have contributed to the life emergence on the Earth
Solar system formation
Link with life
Besides contributing to the formation of the Solar System, comets also appear to have played a key role in the evolution of life on Earth. Some theories suggest that they may have seeded our planet with a large portion of the organic material constituting the basic building blocks of life.
Observations show that comets are partly
composed of water and of complex carbon
molecules, the essential building blocks of life.
Today, it is generally accepted that planets and
comets have the same origin. Thus, information
collected on the comet composition and
evolution processes will allow us to reach
conclusions on the formation and early evolution
Historical case of comets
Comets have been observed and recorded in China since the Shang Dynasty (1600/1046 BC).
The set of comet illustrations shown here is from a silk book written during the Han period (206/220 BC) . The different shapes and characteristics of the comet tails were outlined and on some of the comets, differences in the appearance of the core of the comet were noted.
Besides contributing to the formation of the Solar System, comets also appear to have played a key role in the evolution of life on Earth. Some theories suggest that they may have seeded our planet with a large portion of the organic material constituting the basic building blocks of life.
Historical case of comets
What is a comet ?
With space missions, we have a few images of comet nucleus:
• Halley (1986, Giotto)
• Borrelly (2001, Deep Space 1)
• Wild2 (2004, Stardust)
• Tempel1 (2005, Deep Impact)
What is a comet ?
They appear to be very fragile bodies where outgassing processes may be particularly violent
Model of the nucleus of the Halley comet
Why do they have tails ?
As a comet approaches the Sun,
outgassing leads to the formation
of a dust cloud called the coma,
which may trail a long distance
behind the comet in the form of a
tail blown by solar radiation
pressure and drawn out by the
solar wind.
Most known comets follow a highly elliptical trajectory bringing them periodically close to the Sun.
Some general aspects
Rosetta scientific objectives & measurements
Prime objective: comet observation:
• Origin of comets
• Role in the solar system formation
• Relationship with interstellar material
• Potential link with life
Scientific measurements to be performed to meet these objectives:
• Global characterization of the nucleus
• Characterization of the volatile and refractory materials
Why these names ?
A project has to have a name easy to remember and attractive, including for public
Programmatic aspects
Rosetta development has followed the classical phasing A, B, C/D and E. However, due its
complexity and the launcher problem, the overall duration up to the launch has been long (8 years).
Overall budget ~ 1 G €
Engineering
Engineering: the theoretical case
MISSION REQUIREMENTS
ORBIT(S) PAYLOAD
LAUNCHER
COST but ...
Engineering: the real case
OK : implement development Yes MISSION REQUIREMENTS ORBIT(S) PAYLOAD SPACECRAFT(S) LAUNCHER COST OBJECTIVE No GROUND SEGMENT Fits ? INTERNATIONAL COOPERATION RE-ASSESS EVERYTHING (and change timescale)and/or
The Rosetta trajectory
CD Lander
The Rosetta orbiter
Descent Parameters
duration: beween 0.5 and 3 h impulse < 1 m/s
Landing Parameters
impact velocity : < 1.2 m/s impact angle: < 30 deg attack angle: < 30 deg
Initial Orbit
altitude > 1 km
no éclipse, no impact, no escape
Separation Parameters
amplitude dV < 0.53 m/s (in flight tunable) accuracy dV: 1 %, 0.3 deg (1 sigma)
V comet Landing relative velocity V lander at landing
Impulse at landing and harpoons firing
V orbiter V lander after separation
Impulse during descent (if needed)
dV separation
The Philae lander trajectory
The Philae lander
The ground segment
New Norcia & Camberra stations
The Mechanical & Structural models
Used to validate (at qualification levels) the mechanical and thermal architectures and to generate the final mechanical and thermal specifications of all units
The Electrical models
The Flight models
Used for verification and control (proto-fligth levels)
Launch campaign
The launch campaign : arrival in Rochambeau airport
The launch campaign:
deployment tests
The launch campaign: Electrical test and setting
The launch campaign: satellite fuelling
Launch
Rosetta successfully lifted off from Europe's Spaceport in Kourou, French Guiana, at 04:17 local time (08:17 CET) on 2 March 2004
The inflight operations : commissioning
Immediatly after the launcher separation the spacecraft is activated autonomatically and progressively, through TM/TC links it gets its final configuration. Then the inflight tests are
performed during several weeks to check all the equipments & sub-systems
Satellite solar arrays viewed from the c-lander’s camera CIVA
The inflight operations : Mars swing-by
The inflight operations : asteroids swing-bys
Asteroid Lutetia (July 2010) Asteroid Steins
Conclusions
And to finish …
A HUMAN CHALLENGE BETWEEN INDIVIDUALS !
A HUMAN CHALLENGE BETWEEN INDIVIDUALS !
A project is of course a technical challenge, but it is also…
Advancement of non - involved Chaos
Panic
Search for the guilty
Punishment of the innocent Disillusion Wild Enthusiasm T H E R E A L P H A S E S O F A S P A C E P R O J E C T
Thanks for your attention
Questions ?
