pr395.pdf

NEO Lander assessment DLR January 2006 FROM THE ROSETTA LANDER PHILAE TO AN ASTEROID HOPPER: LANDER CONCEPTS FOR SMALL BODIES MISSIONS S. Ulamec, J. Biele German Aerospace Center (DLR), Köln, Germany, Dokumentname > 23.11.2004 Folie 2 > Vortrag > Autor Outline The investigation of small bodies, comets and asteroids, can contribute substantially to our understanding of the formation and history of the Solar System. In situ observations by Landers play an important role in this field. The Rosetta Lander – Philae – is currently on its way to comet 67P/Churyumov-Gerasimenko. Philae is an example of a ~100 kg landing platform, including a complex and highly integrated payload, consisting of 10 scientific instruments. Other lander designs, more lightweight and with much smaller payload are currently investigated in the frame of a number of missions to small bodies in the Solar System. We will address a number of possible concepts, including mobile surface packages. Dokumentname > 23.11.2004 Folie 3 > Vortrag > Autor Background on small-body landers Historically, there are only two missions which reached the surface of a small body: the NEAR spacecraft touched down on asteroid Eros and Hayabusa attempted to take samples from the surface of Itokawa and recently returned to Earth. In-situ probes can deliver a much higher scientific return if mobility is possible to explore more than one site. We discuss mobility concepts for low-gravity environments including current developments (the MASCOT hopper). Missions aiming for sample return, e.g., asteroid sample return mission Hayabusa-2 , can be significantly enhanced by the implementation of insitu surface packages  help to constrain the geological and physical context of the samples, provide a hold on the evolutionary history of the body by probing its interior. Mobility can even “scout” the most interesting sampling sites on thaNEO Lander assessment DLR January 2006
FROM THE ROSETTA LANDER PHILAE TO AN
ASTEROID HOPPER: LANDER CONCEPTS FOR
SMALL BODIES MISSIONS
S. Ulamec, J. Biele
German Aerospace Center (DLR), Köln, Germany,
Dokumentname > 23.11.2004
Folie 2 > Vortrag > Autor
Outline
The investigation of small bodies, comets and asteroids, can contribute
substantially to our understanding of the formation and history of the
Solar System. In situ observations by Landers play an important role in
this field.
The Rosetta Lander – Philae – is currently on its way to comet
67P/Churyumov-Gerasimenko. Philae is an example of a ~100 kg
landing platform, including a complex and highly integrated payload,
consisting of 10 scientific instruments.
Other lander designs, more lightweight and with much smaller payload
are currently investigated in the frame of a number of missions to small
bodies in the Solar System.
We will address a number of possible concepts, including mobile surface
packages.
Dokumentname > 23.11.2004
Folie 3 > Vortrag > Autor
Background on small-body landers
Historically, there are only two missions which reached the surface of a
small body: the NEAR spacecraft touched down on asteroid Eros and
Hayabusa attempted to take samples from the surface of Itokawa and
recently returned to Earth.
In-situ probes can deliver a much higher scientific return if mobility is
possible to explore more than one site. We discuss mobility concepts for
low-gravity environments including current developments (the MASCOT
hopper).
Missions aiming for sample return, e.g., asteroid sample return mission
Hayabusa-2 , can be significantly enhanced by the implementation of insitu
surface packages  help to constrain the geological and physical
context of the samples, provide a hold on the evolutionary history of the
body by probing its interior.
Mobility can even “scout” the most interesting sampling sites on the
surface
Dokumentname > 23.11.2004
Folie 4 > Vortrag > Autor
Conditions when landing on Small Bodies
Low gravity
Impact velocity can be chosen small even without thrusters (0.5-2 m/s)
Rebounce needs to be minimized
Anchoring to be considered
Uncertainty regarding surface properties
Wide range of surface strength to be considered
Local slopes may be steep
Dust – ice – gas-jets
Usually not spherical … “wobbling potatoes”
Rotation axis may be chaotic
Day night cycle at landing site not trivial to be estimated
Complex descent analysis necessary
Large variations of temperature day/night, heliocentric distance
Dokumentname > 23.11.2004
Folie 5 > Vortrag > Autor
Itokawa (JAXA/Hayabusa))
Wild 2 (NASA/Stardust) Mathilde (NASA/NEAR)
Ida (NASA/Galileo)
Gaspra (NASA/Galileo)
Daktyl (NASA/Galileo)
Tempel 1 (NASA/Deep Impact)
Churyumov-Gerasimenko
Wirtanen
Wilson Harrington
Phobos (ESA/MEX)
Land here
Eros (NASA/NEAR)
Dokumentname > 23.11.2004
Folie 6 > Vortrag > Autor
Phobos (ESA/MEX)
Itokawa (JAXA/Hayabusa))
Halley (MPS/ESA/Giotto)
Wild 2 (NASA/Stardust)
Tempel 1 (NASA/Deep Impact)
Mathilde (NASA/NEAR)
Dokumentname > 23.11.2004
Folie 7 > Vortrag > Autor
Lander strategies
Impactor / Penetrator: not considered!
„Classical Lander“ with landing legs or platform
(e.g. Philae, Phobos-Grunt)
Hopper (e.g. Phobos Hopper)
Opening shell (derivative from Mars Netlander)
„Orbiter Landing“
(e.g. Hayabusa)
Dokumentname > 23.11.2004
Folie 8 > Vortrag > Autor
Rosetta Mission
•Rosetta is an ESA
cornerstone Mission to Comet
67P/Churyumov Gerasimenko
•11 Orbiter Instruments plus
the Lander
•Launch: March 2nd, 2004
•Arrival: May 2014,
•Lander separation: Nov.2014
Dokumentname > 23.11.2004
Folie 9 > Vortrag > Autor
Philae – system overview
Overall mass of about 98 kg (including 26,7 kg of science payload)
based on a carbon fibre / aluminium honeycomb structure
power system including a solar generator, primary- and secondary
batteries
S-band communications system, using the Rosetta Orbiter as relay
Thermal control system: cope with Sun distance 2..3 AU, no RHUs;
double MLI tent, absorbers
Mechanical separation system: 0.05 .. 0.5 m/s to 1% and 0.3deg,
emergency spring eject
Landing Gear: tripod – dissipate landing energy, provide TD signal,
Change of target comet (Wirtanen to Churyumov-Gerasimenko)
prompted stiffening of LG.
Dokumentname > 23.11.2004
Folie 10 > Vortrag > Autor
Mission
Cruise: 10 years
SDL (Descent) 30 .. 60 min: Images, magnetic field, acoustic and IR
mapper calibration, dust impact
First science sequence: feasible only with primary battery, core science,
lasts about 55 hours
Longterm mission: ~3 months (until r<2 AU resp. overheating): very interesting variations with day/night cycle and approach to the sun /activity variations Dokumentname > 23.11.2004
Folie 11 > Vortrag > Autor
Rosetta Trajectory
Dokumentname > 23.11.2004
Folie 12 > Vortrag > Autor
Dokumentname > 23.11.2004
Folie 13 > Vortrag > Autor
Lander FM
Thermal-Vacuum
Test at IABG,
October 2001
Dokumentname > 23.11.2004
Folie 14 > Vortrag > Autor
Schematic view of the Philae spacecraft
N.B.: some instruments are not visible in this
drawing: specifically, the instruments in charge
of analyzing the samples distributed by the SD2
(CIVA, COSAC, PTOLEMY), and the downlooking
camera (ROLIS).
Dokumentname > 23.11.2004
Folie 15 > Vortrag > Autor
Scientific Objectives of the Lander
In-situ-analysis of original material of the Solar System
Elemental and isotope composition
Organic molecules
Minerals and ices
Structure and physical properties of the nucleus
Surface topology
Physical properties
Stratigraphy, global internal structure
Observation of variations with time
Day-night cycle
Approach to the Sun
Dokumentname > 23.11.2004
Folie 16 > Vortrag > Autor
P/L Resources
Mass: 22.01 kg, 26.68 incl. SD2
Power/Energy: currently about 52 – 65 hours of primary mission operation
are feasible with ca. 30% system margin, long term mission relying
entirely on solar cells thereafter
Average power: 15-20 W with primaries, 10 W with solar power alone at
daytime
Data: 235 Mbit during primary mission, 65 Mbit during each subsequent
60 h period
Dokumentname > 23.11.2004
Folie 17 > Vortrag > Autor
² v 1
v 0,lan vor,sep
v rot,com et
R O S E T T A O rbiter
E jectio n m an eu ver
 Separation from the
Orbiter Orbiter adjustable adjustable
velocity of 0,05 to 0,52
m/s
 Descent (gravity)
 Activation of cold gas
system (optional)
 Attitude control with
flywheel
 Soft landing
 Fixation to ground
Landing Scenario
Dokumentname > 23.11.2004
Folie 18 > Vortrag > Autor
Delivery Strategy
A : WITHOUT ROTATION
OR POLAR LANDING
B : WITH ROTATION AND
EQUATORIAL LANDING
Periapsis 1 mean radius (minimises Vorbit)
Delivery at apoapsis (minimises Vimpact)
Vertical free fall
Vorbit Vmss Vorbit
Vmss
Vads
Vrot
Vmss
Dokumentname > 23.11.2004
Folie 19 > Vortrag > Autor
Harpoon Anchoring Device
2 harpoons, accelerated by a
cartridge driven piston
into surface material and connected
by tensioned tether
to the Lander´s landing gear.
Includes MUPUS accelerometers and
temperature sensors
mass of unit: 400g
Projectile: 100g
rewind velocity: 0.5 m/s
anchor velocity: 60 m/s
rewind force(TBC): 1…30 N
max. tether tension: 200 N
max. gas pressure: 250 bar
Dokumentname > 23.11.2004
Folie 20 > Vortrag > Autor
Scalability of the Philae design
The Philae design can be scaled in mass and size to some extent;
internal DLR studies (Witte, 2009) show that similar landers for asteroids
can be designed in a mass range down to about 40 kg and probably well
beyond 150 kg. For very small systems (<< 50 kg), other concepts will be more adequate. Dokumentname > 23.11.2004
Folie 21 > Vortrag > Autor
MASCOT – Lander (proposed for Marco Polo)
A Lander, MASCOT, has been
proposed, following the Instrument
AO for Marco Polo but now foreseen
for Hayabusa-2
Several options (depending e.g. on
the available mass 95- 70 -35- 10 kg)
were studied
A strawman payload has been
suggested:
Ion Laser Mass Analyser
Evolved Gas Analyser
APXS
Mößbauer Spectrometer
Camera Systems (incl. microscope and
IR spectrometer
ATR
Mole – Penetrator
µ-Seismometer
Tomographer Radar instrument
Dokumentname > 23.11.2004
Folie 22 > Vortrag > Autor
A 30 kg „shell Lander“ (DLR/CNES study 2005)
NEO mission to 1996FG3
Landed mass = max. 31 kg incl. margins
0.7 – 1.4 A.U. sun distance, Asteroid diameter 1400 m, bulk density 1100 –
3000 kg/m3, rotational period 3.6 hours
 Vertical touchdown velocity < 1 m/s For a 7.3 kg payload (incl. margins) two options are feasible: either a battery-driven lander with a lifetime of approx. 5 days, or a solar-generator powered lander with a long lifetime (≥ 2 months). Total lander mass is 31 kg, 20% margins are included on each subsystem. As most components of the lander system rely on Netlander phase B developments or Philae FM parts, the design should be quite robust. Delivery is straightforward, as there is no attitude control required. Upon touchdown, two harpoons will anchor the lander and operations can be started. Instruments are assumed to be integrated primarily on the RSS. Thermal system design (large temperature amplitudes, 2:1 changes in solar insulation!) based on Philae heritage. Dokumentname > 23.11.2004
Folie 23 > Vortrag > Autor
NetLander Heritage for an Asteroid Lander
Basic Approach:
• Use the developed mechanical platform of NetLander mainly as it is
• The 4 secondary petals under the main lid are removed
(provided the Lander is battery-driven and does not need solar arrays)
Dokumentname > 23.11.2004
Folie 24 > Vortrag > Autor
Landing in Upright Position
When the Lander has reached its final position (after all rebounces),
the lid is slowly opened and a circumferential hose is inflated.
There is no need to determine the Lander attitude by any sensors in
advance. The operational configuration is reached automatically.
The operational configuration (upright position with lid opened) can
be safely reached from all landing scenarios.
Proper surface contact for the payload units is ensured.
Dokumentname > 23.11.2004
Folie 25 > Vortrag > Autor
Operational Configuration
The operational configuration (upright position with lid
opened) can be safely reached from all landing scenarios.
Proper surface contact for the payload units is ensured.
Dokumentname > 23.11.2004
Folie 26 > Vortrag > Autor
Mobility concepts for small bodies
I. General
Roving by wheeled vehicles is practically impossible
Alternatively, surface elements could move with relatively low
effort by means of propulsion systems (e.g., by cold gas
thrusters)
or using mechanically triggered jumping; the latter discussed in
more detail hereafter. For landers without attitude control during
descent, a self-rightening mechanism has to be foreseen for
proper orientation on the surface after touchdown or after a
mobility operation.
Dokumentname > 23.11.2004
Folie 27 > Vortrag > Autor
PROP-F, the Phobos hopper
45 kg hopper on the Russion Phobos-2
mission (1988)
1-2 km altitude drop over Phobos surface,
no attitude control, impact with 5 m/s
dampened by „pacifier“
Self-righening (see below), hopping: with
„whiskers“ , spring tensioned by motor.
Operations time was limited to about 4
hours and a maximum of 10 jumps (driven by
the capacity of the battery, 30 Ah)
Image courtesy VNII
Transmash
Dokumentname > 23.11.2004
Folie 28 > Vortrag > Autor
Minerva: 0.6 kg robot on
Haybusa-1
Long-lived, excenter mass
uncontrolled hopping
The tests of the orientation mechanism of the mobile probe
with simulated Phobos gravity (courtesy VNIITransmash)
Dokumentname > 23.11.2004
Folie 29 > Vortrag > Autor
Mobility concepts for small bodies
II. Developments for future missions
Mascot XS hopper (see Caroline
Lange et al. Presentation!) inititally with
„whiskers“ or „arms“
A slightly different concept of
mechanically triggered jumping includes
accelerating masses inside the lander
body. Depending on the parameters,
turning or hopping can be achieved.
These concepts are presently under
intense investigation in the context of the
MASCOT project at DLR.
10-15 kg range, 300x300x185 mm3,
Payload mass 3 kg
Scaleable: certainly bigger hoppers
are feasible!
Dokumentname > 23.11.2004
Folie 30 > Vortrag > Autor
MASCOT XS
Dokumentname > 23.11.2004
Folie 31 > Vortrag > Autor
MASCOT XS characteristics
Hopping distance order of 100 m, time 0.5 h, depending on
attitude and latitude for a given asteroid (Trot, size).
Lifetime ~15 hours (batteries only)
Solar generator option is not heavier, but more complex
(deployable petals, more complicated thermal system, operational
constraints)
Dokumentname > 23.11.2004
Folie 32 > Vortrag > Autor
Conclusions
Landers on Comets or Asteroid allow essential
measurements, even in case of a Sample Return
Mission
There is significant heritage in Europa for the
development of Small Bodies Landers; in the range
between ~10kg and >100 kg
Several Missions to small bodies are currently
studied (e.g. Hayabusa-2). All of them could/should
include Landers
Dokumentname > 23.11.2004
Folie 33 > Vortrag > Autor
Additional material
Dokumentname > 23.11.2004
Folie 34 > Vortrag > Autor
Structure
Manufactured in High Modulus Carbon Fibre (DLR Braunschweig,
Institute for Structural Mechanics)
Consists of
Baseplate
Experiment Carrier
Hood
Struts + Support Elements
Conductive Cover on outer Surfaces
Dokumentname > 23.11.2004
Folie 35 > Vortrag > Autor
Drill and Sampling Device SD2
•SD2 manufactured by Tecnospazio, Milano
under ASI contract
•Drill depth up to 230 mm
•drill-collect-transport to carousel-volume
checker – rotate carousel and present for
analysis
•Mass 3.6 kg
•Power 5 to 12 W
Dokumentname > 23.11.2004
Folie 36 > Vortrag > Autor
Missions and Studies
Phobos (1988-1989)
Included long term Lander and Hopper
Mission failed during approach
NEAR (1996 – 1997)
Rosetta Lander (2004 – 2014)
Philae (on ist way to Churyumov-Gerasimenko)
Concepts for smaller Landers: RoLand and Champollion
Hayabusa (2003)
Deep Impact (2005)
Phobos Grunt (2009 tbc)
Leonard (CNES-DLR-ASI study)
Marco Polo (ESA/(JAXA) Cosmic Vision study)
MASCOT (DLR-CNES-JAXA, ongoing)
Dokumentname > 23.11.2004
Folie 37 > Vortrag > Autor
Mass breakdown Unit Mass [kg]
Structure 18,0
Thermal Control System
(/MLI)
3,9 (/2,7)
Power System (/ Batteries / Solar
Generator)
12,2 (/8,5/1,7)
Active Descent System 4,1
Flywheel 2,9
Landing Gear 10,0
Anchoring System 1,4
CDMS 2,9
TxRx 2,4
Common Electronics Box 9,8
MSS (on Lander), Harness,
balancing mass
3,6
Payload 26,7
Sum [Lander] 97,9
ESS, TxRx (on Orbiter) 4,4
MSS, harness 8,7
Sum [incl. Orbiter units] 111,0
Dokumentname > 23.11.2004
Folie 38 > Vortrag > Autor
PHILAE, THE ROSETTA LANDER:
the target is almost unknown
Engineering models for the comet surface properties covered a range for
the compressive strength between 60 kPa and 2 MPa. The surface
roughness is completely unknown. Extreme surface compressive
strengths down to a few kPa are now covered as well.
The results of space missions to various asteroids and comets indicate
that these bodies show a very wide range of surface characteristics and
are very different to each other.
Dokumentname > 23.11.2004
Folie 39 > Vortrag > Autor
Technical Challenge developing Philae (and merging
two smaller Landers both proposed for Rosetta)
Soft Landing on a Comet –
Nobody has tried this so far… How soft is the comet, anyway?
Size, mass, day-night period, temperature and surface properties
of the comet are only vaguely known
Longterm Operations of a Lander in Deep Space without RTG´s
10 Science Instruments aboard a 100 kg Lander
Dokumentname > 23.11.2004
Folie 40 > Vortrag > Autor
Target: Comet 67P/Churyumov-Gerasimenko
Characteristica:
Diameter ~4000 m
Density 0.2-1.5 gcm-3
Aphelion 5.75 AU
Perihel 1.3 AU
Orb.period 6.57 years
Albedo ca. 0.04
Rotation 12,7 h
latest Perihel: 2009 Feb 28
Discovered by Klim Churyumov in
photographs of 32P/Comas Solá taken
by Svetlana Gerasimenko on 22 October
1969.
Dokumentname > 23.11.2004
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Contribution of Philae to the Orbiter Science
Phenomena which are not observable remotely by the Rosetta Orbiter:
local erosion of the surface by sublimating ices, modifications of texture and chemical
composition of near surface materials, changes in dust precipitation and heat flux
through the surface, which is the determining parameter for all processes modifying
cometary material.
CONSERT
Seismometry and magnetometry will also be used to investigate the interior of the comet.
Local ground truth to calibrate Orbiter instruments.
Calibration of albedo and topographical features observed by the Orbiter camera.
In-situ chemical and mineralogical analysis of surface material by the Lander payload
provides a means to correlate chemical and mineralogical compositions with
brightness at various infrared wavelengths observed by the Orbiter.
Dokumentname > 23.11.2004
Folie 42 > Vortrag > Autor
Landing system
Damping of landing
Rotation and hight adjustment
Anchoring with harpune
„Hold-down Thruster“
Energy- und Thermal-Concept
Solar generator 11 W (at 3AU)
Primary and secondary batteries
„warm“ and „cold“ areas
Drill /Sampling Device
Drill depth 20 cm
multiple sampling
low temperature modifications
Data
Central computer
Data relay via Orbiter (16 kb/s)
Lander Characteristica
Dokumentname > 23.11.2004
Folie 43 > Vortrag > Autor
The Consortium
System contributions Instruments
•DLR (Köln, Braunschweig)
•MPG (Lindau, Garching) MPG (Lindau, Garching)
•CNES (Paris, Toulouse) CNES (Paris, Toulouse)
•ASI (Rom, Matera) ASI (Rom, Matera)
•KFKI (Budapest) KFKI (Budapest)
•TU-Budapest Budapest
•STIL (Maynooth) STIL (Maynooth)
•FMI (Helsinki) FMI (Helsinki)
•RAL (Chilton) RAL (Chilton)
•IWF (Graz) IWF (Graz)
•ESA
•MPG (Lindau, Mainz, Garching) MPG (Lindau, Mainz, Garching)
•IAS, Orsay IAS, Orsay
•DLR (Köln, Berlin)
•Open University (Milton Open University (Milton
Keynes)
•KFKI (Budapest) KFKI (Budapest)
•FMI (Helsinki) FMI (Helsinki)
•Universität Münster
•CEPHAG (Grenoble) CEPHAG (Grenoble)
•Politecnico Milano Politecnico Milano
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Scientific Instruments
Material Analysis
COSAC (MPS)
MODULUS (OU)
APX (MPCh/Uni Mainz)
Cameras
ÇIVA (IAS)
ROLIS (DLR)
Structure
SESAME (DLR)
CONSERT (LPG)
MUPUS (U. Münster/DLR)
Plasma/Magnetic Environment
ROMAP (TU Braunschweig)
Sampling & Drilling Device
SD
2 (Politecnico Milano)
Dokumentname > 23.11.2004
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Side view schematics of the inner structure of the lander
compartment
Dokumentname > 23.11.2004
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SD2
ÇIVA
ROMAP
MUPUS
Balcony payload („cold compartment“)
APX
Dokumentname > 23.11.2004
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Local Environment
Unknown topography and
surface
Shape [km] about 3×5
Temperatures
Day ~ -80 to 200 °C
Night > -160 °C
Rotation period 12,3 h
Surface strength:
1 kPa to 2 MPa (??)
Gravity ~10-4 g
Comet Surface Temperature
100
120
140
160
180
200
220
-180 -135 -90 -45 0 45 90 135 180
Rotation angle
Temperature [K]
1.06 AU
2 AU
3AU
Sunrise
Noon
Sunset
Dokumentname > 23.11.2004
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Implications of Change of Target Comet
Increased Mission Time
Experimenters need to live even healthier…. landing in 2014
Churyumov-G. is considerably bigger than Wirtanen
increased landing velocity
stiffened cardanic joint in landing gear
iterated requirements regardind separation altitude (>1km)
different dust environment
baseline landing still at 3 AU
(from Wirtanen to CG)
Dokumentname > 23.11.2004
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SUBSYSTEMS
Warm (-40°C) and cold (ambient cometary temperatures > -200°C) areas
Solar absorbers on top panel
Electrical power dissipation about 10W average
No use of Radioisotope Heater Units (RHUs)
Thermal Control System
Dokumentname > 23.11.2004
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Power System
Power to be provided with solar generators and by batteries.
LILT solar cells (Si-based technology) 10-12 W @ day (3 a.u.)
Li/SOCl2-primary batteries (about 1000 Wh) Li-ion
secondary batteries (about 140 Wh)
Bootstrap procedure („wakeup“)
Dokumentname > 23.11.2004
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Telecommunications TxRx
Telecommunication via Rosetta Orbiter, S-Band omnidir., redundant
Data rate 16 kbit/sec
Hard-coded TCs possible
Blind commanding possible
Max distance Lander-Orbiter: 150 km
Highest Priority 1 week prior and 1 week after separation (with high
fraction of visibility periods)
Priority as Orbiter instruments during long-term operations
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On-board computer: CDMS
Provides central computing and data storage capability (2×2 Mbyte,
RAM, EEPROM)
Acts as interface to the telecoms system
Gouverns sequence of subsystem- and payload operations
Provided by a Hungarian Consortium (KFKI Budapest, U Budapest)
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MOST FAVORABLE
LANDING AREAS
FROM THIS LIGHT CURVE DERIVED
FROM HST OBSERVATIONS
ON MARCH 2003 ,
THE P.LAMY TEAM MODELLED
A POSSIBLE CG NUCLEUS SHAPE
(DPS 2003 presentation – CNES/NASA grant)
Shape, Landing areas
Dokumentname > 23.11.2004
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Landing strategy
delivery foreseen in November 2014 at a distance of about 3 Astronomical Units (AU) to the
Sun
change of the target comet has a major impact on the Philae landing safety, since the
expected touchdown velocity is much higher than in the case of P/Wirtanen (the original
target of the Rosetta mission), due to the much larger size of P/Churyumov-Gerasimenko.
Some hardware changes have been implemented, to increase robustness at touch-down.
However, the safe landing remains highly sensitive to actual nucleus properties, largely
unknown at this time.
Consequently, a dedicated mapping phase will take place several months prior to
separation, acquiring data from Orbiter instruments to update environmental and surface
cometary models, towards an optimized selection of the landing site and of the release
strategy.
Following touch-down, Philae will have mission priority over Orbiter investigations for one
week
After this phase, Philae will share resources with the Orbiter investigations.
Dokumentname > 23.11.2004
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Touchdown Simulation
Landing with vimpact of 1.2 m/s at a local slope of 30°
Free cardanic joint Cardanic joint fixed to ± 5°
Dokumentname > 23.11.2004
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Cardanic
joint
Bubble rotation limitation simulation:
The bubble rotation is free
for about 5°, 2.5° for the
cardanic joint and 2.5° for
the rotational torsion of the
landing gear. The rotation
is limited by a hard spring.
Dokumentname > 23.11.2004
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Mars Swingby 2007: Some results
Closest Approach: 250.6 km
CIVA deliveres spectacular images
ROMAP detects Bow Shock
© CIVA/Philae/ESA
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Steins and Lutetia flybys
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0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
01/2
0
0
4
0
7/2
0
0
4
01/2
0
0
5
0
7/2
0
0
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01/2
0
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7/2
0
0
6
01/2
0
0
7
0
7/2
0
0
7
01/2
0
0
8
0
7/2
0
0
8
01/2
0
0
9
0
7/2
0
0
9
01/2
010
0
7/2
010
01/2
011
0
7/2
011
01/2
012
0
7/2
012
01/2
013
0
7/2
013
01/2
014
0
7/2
014
01/2
015
0
7/2
015
Date
Dista
n
c
e (A
U)
Earth Distance
Sun Distance
Launch
020304
Earth Flyby
Mars Flyby
250207
RVM 1
230111
RVM 2
220514
Steins Flyby
050908
Earth Flyby
Earth Flyby
Comet Orbit
Insertion
220814
Landing
101114
Lutetia Flyby
100710
Future events
Dokumentname > 23.11.2004
Folie 60 > Vortrag > Autor
Landing Shock Tests on NetLander
Drop tests in the airbag belts (180 g deceleration) and impact tests on sand
and on hard ground were successfully performed
NetLander survives 2.5 m/s on hard ground without any damage
Internal payload and subsystem units can be shock-protected by mounting
on the internal baseplate, which is only softly coupled with the „hard“
structure
 No airbags are needed for landing scenarios with  1 m/s
Dokumentname > 23.11.2004
Folie 61 > Vortrag > Autor
Landing in Upside-Down Position
In case of upside-down landing, the opening mechanism of the lid
will tilt the Lander until it falls (very slowly) into the upright position.
Repeated attempts are possible.
The uprighting mechanism was developed and qualified for Mars
environment, and can be adapted to very-low-gravity environment.
Dokumentname > 23.11.2004
Folie 62 > Vortrag > Autor
Structural Configuration (without the Lid)
Primary structure (carbonfiber) 2980 g
Lid (not shown on the photo) 1350 g
Mass dummies
of E-boxes
Silica isolation
Payload
instruments
on this sidee surface Dokumentname > 23.11.2004 Folie 4 > Vortrag > Autor Conditions when landing on Small Bodies Low gravity Impact velocity can be chosen small even without thrusters (0.5-2 m/s) Rebounce needs to be minimized Anchoring to be considered Uncertainty regarding surface properties Wide range of surface strength to be considered Local slopes may be steep Dust – ice – gas-jets Usually not spherical … “wobbling potatoes” Rotation axis may be chaotic Day night cycle at landing site not trivial to be estimated Complex descent analysis necessary Large variations of temperature day/night, heliocentric distance Dokumentname > 23.11.2004 Folie 5 > Vortrag > Autor Itokawa (JAXA/Hayabusa)) Wild 2 (NASA/Stardust) Mathilde (NASA/NEAR) Ida (NASA/Galileo) Gaspra (NASA/Galileo) Daktyl (NASA/Galileo) Tempel 1 (NASA/Deep Impact) Churyumov-Gerasimenko Wirtanen Wilson Harrington Phobos (ESA/MEX) Land here Eros (NASA/NEAR) Dokumentname > 23.11.2004 Folie 6 > Vortrag > Autor Phobos (ESA/MEX) Itokawa (JAXA/Hayabusa)) Halley (MPS/ESA/Giotto) Wild 2 (NASA/Stardust) Tempel 1 (NASA/Deep Impact) Mathilde (NASA/NEAR) Dokumentname > 23.11.2004 Folie 7 > Vortrag > Autor Lander strategies Impactor / Penetrator: not considered! „Classical Lander“ with landing legs or platform (e.g. Philae, Phobos-Grunt) Hopper (e.g. Phobos Hopper) Opening shell (derivative from Mars Netlander) „Orbiter Landing“ (e.g. Hayabusa) Dokumentname > 23.11.2004 Folie 8 > Vortrag > Autor Rosetta Mission •Rosetta is an ESA cornerstone Mission to Comet 67P/Churyumov Gerasimenko •11 Orbiter Instruments plus the Lander •Launch: March 2nd, 2004 •Arrival: May 2014, •Lander separation: Nov.2014 Dokumentname > 23.11.2004 Folie 9 > Vortrag > Autor Philae – system overview Overall mass of about 98 kg (including 26,7 kg of science payload) based on a carbon fibre / aluminium honeycomb structure power system including a solar generator, primary- and secondary batteries S-band communications system, using the Rosetta Orbiter as relay Thermal control system: cope with Sun distance 2..3 AU, no RHUs; double MLI tent, absorbers Mechanical separation system: 0.05 .. 0.5 m/s to 1% and 0.3deg, emergency spring eject Landing Gear: tripod – dissipate landing energy, provide TD signal, Change of target comet (Wirtanen to Churyumov-Gerasimenko) prompted stiffening of LG. Dokumentname > 23.11.2004 Folie 10 > Vortrag > Autor Mission Cruise: 10 years SDL (Descent) 30 .. 60 min: Images, magnetic field, acoustic and IR mapper calibration, dust impact First science sequence: feasible only with primary battery, core science, lasts about 55 hours Longterm mission: ~3 months (until r<2 AU resp. overheating): very interesting variations with day/night cycle and approach to the sun /activity variations Dokumentname > 23.11.2004 Folie 11 > Vortrag > Autor Rosetta Trajectory Dokumentname > 23.11.2004 Folie 12 > Vortrag > Autor Dokumentname > 23.11.2004 Folie 13 > Vortrag > Autor Lander FM Thermal-Vacuum Test at IABG, October 2001 Dokumentname > 23.11.2004 Folie 14 > Vortrag > Autor Schematic view of the Philae spacecraft N.B.: some instruments are not visible in this drawing: specifically, the instruments in charge of analyzing the samples distributed by the SD2 (CIVA, COSAC, PTOLEMY), and the downlooking camera (ROLIS). Dokumentname > 23.11.2004 Folie 15 > Vortrag > Autor Scientific Objectives of the Lander In-situ-analysis of original material of the Solar System Elemental and isotope composition Organic molecules Minerals and ices Structure and physical properties of the nucleus Surface topology Physical properties Stratigraphy, global internal structure Observation of variations with time Day-night cycle Approach to the Sun Dokumentname > 23.11.2004 Folie 16 > Vortrag > Autor P/L Resources Mass: 22.01 kg, 26.68 incl. SD2 Power/Energy: currently about 52 – 65 hours of primary mission operation are feasible with ca. 30% system margin, long term mission relying entirely on solar cells thereafter Average power: 15-20 W with primaries, 10 W with solar power alone at daytime Data: 235 Mbit during primary mission, 65 Mbit during each subsequent 60 h period Dokumentname > 23.11.2004 Folie 17 > Vortrag > Autor ² v 1 v 0,lan vor,sep v rot,com et R O S E T T A O rbiter E jectio n m an eu ver  Separation from the Orbiter Orbiter adjustable adjustable velocity of 0,05 to 0,52 m/s  Descent (gravity)  Activation of cold gas system (optional)  Attitude control with flywheel  Soft landing  Fixation to ground Landing Scenario Dokumentname > 23.11.2004 Folie 18 > Vortrag > Autor Delivery Strategy A : WITHOUT ROTATION OR POLAR LANDING B : WITH ROTATION AND EQUATORIAL LANDING Periapsis 1 mean radius (minimises Vorbit) Delivery at apoapsis (minimises Vimpact) Vertical free fall Vorbit Vmss Vorbit Vmss Vads Vrot Vmss Dokumentname > 23.11.2004 Folie 19 > Vortrag > Autor Harpoon Anchoring Device 2 harpoons, accelerated by a cartridge driven piston into surface material and connected by tensioned tether to the Lander´s landing gear. Includes MUPUS accelerometers and temperature sensors mass of unit: 400g Projectile: 100g rewind velocity: 0.5 m/s anchor velocity: 60 m/s rewind force(TBC): 1…30 N max. tether tension: 200 N max. gas pressure: 250 bar Dokumentname > 23.11.2004 Folie 20 > Vortrag > Autor Scalability of the Philae design The Philae design can be scaled in mass and size to some extent; internal DLR studies (Witte, 2009) show that similar landers for asteroids can be designed in a mass range down to about 40 kg and probably well beyond 150 kg. For very small systems (<< 50 kg), other concepts will be more adequate. Dokumentname > 23.11.2004 Folie 21 > Vortrag > Autor MASCOT – Lander (proposed for Marco Polo) A Lander, MASCOT, has been proposed, following the Instrument AO for Marco Polo but now foreseen for Hayabusa-2 Several options (depending e.g. on the available mass 95- 70 -35- 10 kg) were studied A strawman payload has been suggested: Ion Laser Mass Analyser Evolved Gas Analyser APXS Mößbauer Spectrometer Camera Systems (incl. microscope and IR spectrometer ATR Mole – Penetrator µ-Seismometer Tomographer Radar instrument Dokumentname > 23.11.2004 Folie 22 > Vortrag > Autor A 30 kg „shell Lander“ (DLR/CNES study 2005) NEO mission to 1996FG3 Landed mass = max. 31 kg incl. margins 0.7 – 1.4 A.U. sun distance, Asteroid diameter 1400 m, bulk density 1100 – 3000 kg/m3, rotational period 3.6 hours  Vertical touchdown velocity < 1 m/s For a 7.3 kg payload (incl. margins) two options are feasible: either a battery-driven lander with a lifetime of approx. 5 days, or a solar-generator powered lander with a long lifetime (≥ 2 months). Total lander mass is 31 kg, 20% margins are included on each subsystem. As most components of the lander system rely on Netlander phase B developments or Philae FM parts, the design should be quite robust. Delivery is straightforward, as there is no attitude control required. Upon touchdown, two harpoons will anchor the lander and operations can be started. Instruments are assumed to be integrated primarily on the RSS. Thermal system design (large temperature amplitudes, 2:1 changes in solar insulation!) based on Philae heritage. Dokumentname > 23.11.2004 Folie 23 > Vortrag > Autor NetLander Heritage for an Asteroid Lander Basic Approach: • Use the developed mechanical platform of NetLander mainly as it is • The 4 secondary petals under the main lid are removed (provided the Lander is battery-driven and does not need solar arrays) Dokumentname > 23.11.2004 Folie 24 > Vortrag > Autor Landing in Upright Position When the Lander has reached its final position (after all rebounces), the lid is slowly opened and a circumferential hose is inflated. There is no need to determine the Lander attitude by any sensors in advance. The operational configuration is reached automatically. The operational configuration (upright position with lid opened) can be safely reached from all landing scenarios. Proper surface contact for the payload units is ensured. Dokumentname > 23.11.2004 Folie 25 > Vortrag > Autor Operational Configuration The operational configuration (upright position with lid opened) can be safely reached from all landing scenarios. Proper surface contact for the payload units is ensured. Dokumentname > 23.11.2004 Folie 26 > Vortrag > Autor Mobility concepts for small bodies I. General Roving by wheeled vehicles is practically impossible Alternatively, surface elements could move with relatively low effort by means of propulsion systems (e.g., by cold gas thrusters) or using mechanically triggered jumping; the latter discussed in more detail hereafter. For landers without attitude control during descent, a self-rightening mechanism has to be foreseen for proper orientation on the surface after touchdown or after a mobility operation. Dokumentname > 23.11.2004 Folie 27 > Vortrag > Autor PROP-F, the Phobos hopper 45 kg hopper on the Russion Phobos-2 mission (1988) 1-2 km altitude drop over Phobos surface, no attitude control, impact with 5 m/s dampened by „pacifier“ Self-righening (see below), hopping: with „whiskers“ , spring tensioned by motor. Operations time was limited to about 4 hours and a maximum of 10 jumps (driven by the capacity of the battery, 30 Ah) Image courtesy VNII Transmash Dokumentname > 23.11.2004 Folie 28 > Vortrag > Autor Minerva: 0.6 kg robot on Haybusa-1 Long-lived, excenter mass uncontrolled hopping The tests of the orientation mechanism of the mobile probe with simulated Phobos gravity (courtesy VNIITransmash) Dokumentname > 23.11.2004 Folie 29 > Vortrag > Autor Mobility concepts for small bodies II. Developments for future missions Mascot XS hopper (see Caroline Lange et al. Presentation!) inititally with „whiskers“ or „arms“ A slightly different concept of mechanically triggered jumping includes accelerating masses inside the lander body. Depending on the parameters, turning or hopping can be achieved. These concepts are presently under intense investigation in the context of the MASCOT project at DLR. 10-15 kg range, 300x300x185 mm3, Payload mass 3 kg Scaleable: certainly bigger hoppers are feasible! Dokumentname > 23.11.2004 Folie 30 > Vortrag > Autor MASCOT XS Dokumentname > 23.11.2004 Folie 31 > Vortrag > Autor MASCOT XS characteristics Hopping distance order of 100 m, time 0.5 h, depending on attitude and latitude for a given asteroid (Trot, size). Lifetime ~15 hours (batteries only) Solar generator option is not heavier, but more complex (deployable petals, more complicated thermal system, operational constraints) Dokumentname > 23.11.2004 Folie 32 > Vortrag > Autor Conclusions Landers on Comets or Asteroid allow essential measurements, even in case of a Sample Return Mission There is significant heritage in Europa for the development of Small Bodies Landers; in the range between ~10kg and >100 kg Several Missions to small bodies are currently studied (e.g. Hayabusa-2). All of them could/should include Landers Dokumentname > 23.11.2004 Folie 33 > Vortrag > Autor Additional material Dokumentname > 23.11.2004 Folie 34 > Vortrag > Autor Structure Manufactured in High Modulus Carbon Fibre (DLR Braunschweig, Institute for Structural Mechanics) Consists of Baseplate Experiment Carrier Hood Struts + Support Elements Conductive Cover on outer Surfaces Dokumentname > 23.11.2004 Folie 35 > Vortrag > Autor Drill and Sampling Device SD2 •SD2 manufactured by Tecnospazio, Milano under ASI contract •Drill depth up to 230 mm •drill-collect-transport to carousel-volume checker – rotate carousel and present for analysis •Mass 3.6 kg •Power 5 to 12 W Dokumentname > 23.11.2004 Folie 36 > Vortrag > Autor Missions and Studies Phobos (1988-1989) Included long term Lander and Hopper Mission failed during approach NEAR (1996 – 1997) Rosetta Lander (2004 – 2014) Philae (on ist way to Churyumov-Gerasimenko) Concepts for smaller Landers: RoLand and Champollion Hayabusa (2003) Deep Impact (2005) Phobos Grunt (2009 tbc) Leonard (CNES-DLR-ASI study) Marco Polo (ESA/(JAXA) Cosmic Vision study) MASCOT (DLR-CNES-JAXA, ongoing) Dokumentname > 23.11.2004 Folie 37 > Vortrag > Autor Mass breakdown Unit Mass [kg] Structure 18,0 Thermal Control System (/MLI) 3,9 (/2,7) Power System (/ Batteries / Solar Generator) 12,2 (/8,5/1,7) Active Descent System 4,1 Flywheel 2,9 Landing Gear 10,0 Anchoring System 1,4 CDMS 2,9 TxRx 2,4 Common Electronics Box 9,8 MSS (on Lander), Harness, balancing mass 3,6 Payload 26,7 Sum [Lander] 97,9 ESS, TxRx (on Orbiter) 4,4 MSS, harness 8,7 Sum [incl. Orbiter units] 111,0 Dokumentname > 23.11.2004 Folie 38 > Vortrag > Autor PHILAE, THE ROSETTA LANDER: the target is almost unknown Engineering models for the comet surface properties covered a range for the compressive strength between 60 kPa and 2 MPa. The surface roughness is completely unknown. Extreme surface compressive strengths down to a few kPa are now covered as well. The results of space missions to various asteroids and comets indicate that these bodies show a very wide range of surface characteristics and are very different to each other. Dokumentname > 23.11.2004 Folie 39 > Vortrag > Autor Technical Challenge developing Philae (and merging two smaller Landers both proposed for Rosetta) Soft Landing on a Comet – Nobody has tried this so far… How soft is the comet, anyway? Size, mass, day-night period, temperature and surface properties of the comet are only vaguely known Longterm Operations of a Lander in Deep Space without RTG´s 10 Science Instruments aboard a 100 kg Lander Dokumentname > 23.11.2004 Folie 40 > Vortrag > Autor Target: Comet 67P/Churyumov-Gerasimenko Characteristica: Diameter ~4000 m Density 0.2-1.5 gcm-3 Aphelion 5.75 AU Perihel 1.3 AU Orb.period 6.57 years Albedo ca. 0.04 Rotation 12,7 h latest Perihel: 2009 Feb 28 Discovered by Klim Churyumov in photographs of 32P/Comas Solá taken by Svetlana Gerasimenko on 22 October 1969. Dokumentname > 23.11.2004 Folie 41 > Vortrag > Autor Contribution of Philae to the Orbiter Science Phenomena which are not observable remotely by the Rosetta Orbiter: local erosion of the surface by sublimating ices, modifications of texture and chemical composition of near surface materials, changes in dust precipitation and heat flux through the surface, which is the determining parameter for all processes modifying cometary material. CONSERT Seismometry and magnetometry will also be used to investigate the interior of the comet. Local ground truth to calibrate Orbiter instruments. Calibration of albedo and topographical features observed by the Orbiter camera. In-situ chemical and mineralogical analysis of surface material by the Lander payload provides a means to correlate chemical and mineralogical compositions with brightness at various infrared wavelengths observed by the Orbiter. Dokumentname > 23.11.2004 Folie 42 > Vortrag > Autor Landing system Damping of landing Rotation and hight adjustment Anchoring with harpune „Hold-down Thruster“ Energy- und Thermal-Concept Solar generator 11 W (at 3AU) Primary and secondary batteries „warm“ and „cold“ areas Drill /Sampling Device Drill depth 20 cm multiple sampling low temperature modifications Data Central computer Data relay via Orbiter (16 kb/s) Lander Characteristica Dokumentname > 23.11.2004 Folie 43 > Vortrag > Autor The Consortium System contributions Instruments •DLR (Köln, Braunschweig) •MPG (Lindau, Garching) MPG (Lindau, Garching) •CNES (Paris, Toulouse) CNES (Paris, Toulouse) •ASI (Rom, Matera) ASI (Rom, Matera) •KFKI (Budapest) KFKI (Budapest) •TU-Budapest Budapest •STIL (Maynooth) STIL (Maynooth) •FMI (Helsinki) FMI (Helsinki) •RAL (Chilton) RAL (Chilton) •IWF (Graz) IWF (Graz) •ESA •MPG (Lindau, Mainz, Garching) MPG (Lindau, Mainz, Garching) •IAS, Orsay IAS, Orsay •DLR (Köln, Berlin) •Open University (Milton Open University (Milton Keynes) •KFKI (Budapest) KFKI (Budapest) •FMI (Helsinki) FMI (Helsinki) •Universität Münster •CEPHAG (Grenoble) CEPHAG (Grenoble) •Politecnico Milano Politecnico Milano Dokumentname > 23.11.2004 Folie 44 > Vortrag > Autor Scientific Instruments Material Analysis COSAC (MPS) MODULUS (OU) APX (MPCh/Uni Mainz) Cameras ÇIVA (IAS) ROLIS (DLR) Structure SESAME (DLR) CONSERT (LPG) MUPUS (U. Münster/DLR) Plasma/Magnetic Environment ROMAP (TU Braunschweig) Sampling & Drilling Device SD 2 (Politecnico Milano) Dokumentname > 23.11.2004 Folie 45 > Vortrag > Autor Side view schematics of the inner structure of the lander compartment Dokumentname > 23.11.2004 Folie 46 > Vortrag > Autor SD2 ÇIVA ROMAP MUPUS Balcony payload („cold compartment“) APX Dokumentname > 23.11.2004 Folie 47 > Vortrag > Autor Local Environment Unknown topography and surface Shape [km] about 3×5 Temperatures Day ~ -80 to 200 °C Night > -160 °C Rotation period 12,3 h Surface strength: 1 kPa to 2 MPa (??) Gravity ~10-4 g Comet Surface Temperature 100 120 140 160 180 200 220 -180 -135 -90 -45 0 45 90 135 180 Rotation angle Temperature [K] 1.06 AU 2 AU 3AU Sunrise Noon Sunset Dokumentname > 23.11.2004 Folie 48 > Vortrag > Autor Implications of Change of Target Comet Increased Mission Time Experimenters need to live even healthier…. landing in 2014 Churyumov-G. is considerably bigger than Wirtanen increased landing velocity stiffened cardanic joint in landing gear iterated requirements regardind separation altitude (>1km) different dust environment baseline landing still at 3 AU (from Wirtanen to CG) Dokumentname > 23.11.2004 Folie 49 > Vortrag > Autor SUBSYSTEMS Warm (-40°C) and cold (ambient cometary temperatures > -200°C) areas Solar absorbers on top panel Electrical power dissipation about 10W average No use of Radioisotope Heater Units (RHUs) Thermal Control System Dokumentname > 23.11.2004 Folie 50 > Vortrag > Autor Power System Power to be provided with solar generators and by batteries. LILT solar cells (Si-based technology) 10-12 W @ day (3 a.u.) Li/SOCl2-primary batteries (about 1000 Wh) Li-ion secondary batteries (about 140 Wh) Bootstrap procedure („wakeup“) Dokumentname > 23.11.2004 Folie 51 > Vortrag > Autor Telecommunications TxRx Telecommunication via Rosetta Orbiter, S-Band omnidir., redundant Data rate 16 kbit/sec Hard-coded TCs possible Blind commanding possible Max distance Lander-Orbiter: 150 km Highest Priority 1 week prior and 1 week after separation (with high fraction of visibility periods) Priority as Orbiter instruments during long-term operations Dokumentname > 23.11.2004 Folie 52 > Vortrag > Autor On-board computer: CDMS Provides central computing and data storage capability (2×2 Mbyte, RAM, EEPROM) Acts as interface to the telecoms system Gouverns sequence of subsystem- and payload operations Provided by a Hungarian Consortium (KFKI Budapest, U Budapest) Dokumentname > 23.11.2004 Folie 53 > Vortrag > Autor MOST FAVORABLE LANDING AREAS FROM THIS LIGHT CURVE DERIVED FROM HST OBSERVATIONS ON MARCH 2003 , THE P.LAMY TEAM MODELLED A POSSIBLE CG NUCLEUS SHAPE (DPS 2003 presentation – CNES/NASA grant) Shape, Landing areas Dokumentname > 23.11.2004 Folie 54 > Vortrag > Autor Landing strategy delivery foreseen in November 2014 at a distance of about 3 Astronomical Units (AU) to the Sun change of the target comet has a major impact on the Philae landing safety, since the expected touchdown velocity is much higher than in the case of P/Wirtanen (the original target of the Rosetta mission), due to the much larger size of P/Churyumov-Gerasimenko. Some hardware changes have been implemented, to increase robustness at touch-down. However, the safe landing remains highly sensitive to actual nucleus properties, largely unknown at this time. Consequently, a dedicated mapping phase will take place several months prior to separation, acquiring data from Orbiter instruments to update environmental and surface cometary models, towards an optimized selection of the landing site and of the release strategy. Following touch-down, Philae will have mission priority over Orbiter investigations for one week After this phase, Philae will share resources with the Orbiter investigations. Dokumentname > 23.11.2004 Folie 55 > Vortrag > Autor Touchdown Simulation Landing with vimpact of 1.2 m/s at a local slope of 30° Free cardanic joint Cardanic joint fixed to ± 5° Dokumentname > 23.11.2004 Folie 56 > Vortrag > Autor Cardanic joint Bubble rotation limitation simulation: The bubble rotation is free for about 5°, 2.5° for the cardanic joint and 2.5° for the rotational torsion of the landing gear. The rotation is limited by a hard spring. Dokumentname > 23.11.2004 Folie 57 > Vortrag > Autor Mars Swingby 2007: Some results Closest Approach: 250.6 km CIVA deliveres spectacular images ROMAP detects Bow Shock © CIVA/Philae/ESA Dokumentname > 23.11.2004 Folie 58 > Vortrag > Autor Steins and Lutetia flybys Dokumentname > 23.11.2004 Folie 59 > Vortrag > Autor 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 01/2 0 0 4 0 7/2 0 0 4 01/2 0 0 5 0 7/2 0 0 5 01/2 0 0 6 0 7/2 0 0 6 01/2 0 0 7 0 7/2 0 0 7 01/2 0 0 8 0 7/2 0 0 8 01/2 0 0 9 0 7/2 0 0 9 01/2 010 0 7/2 010 01/2 011 0 7/2 011 01/2 012 0 7/2 012 01/2 013 0 7/2 013 01/2 014 0 7/2 014 01/2 015 0 7/2 015 Date Dista n c e (A U) Earth Distance Sun Distance Launch 020304 Earth Flyby Mars Flyby 250207 RVM 1 230111 RVM 2 220514 Steins Flyby 050908 Earth Flyby Earth Flyby Comet Orbit Insertion 220814 Landing 101114 Lutetia Flyby 100710 Future events Dokumentname > 23.11.2004 Folie 60 > Vortrag > Autor Landing Shock Tests on NetLander Drop tests in the airbag belts (180 g deceleration) and impact tests on sand and on hard ground were successfully performed NetLander survives 2.5 m/s on hard ground without any damage Internal payload and subsystem units can be shock-protected by mounting on the internal baseplate, which is only softly coupled with the „hard“ structure  No airbags are needed for landing scenarios with  1 m/s Dokumentname > 23.11.2004 Folie 61 > Vortrag > Autor Landing in Upside-Down Position In case of upside-down landing, the opening mechanism of the lid will tilt the Lander until it falls (very slowly) into the upright position. Repeated attempts are possible. The uprighting mechanism was developed and qualified for Mars environment, and can be adapted to very-low-gravity environment. Dokumentname > 23.11.2004 Folie 62 > Vortrag > Autor Structural Configuration (without the Lid) Primary structure (carbonfiber) 2980 g Lid (not shown on the photo) 1350 g Mass dummies of E-boxes Silica isolation Payload instruments on this side