Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.iki.rssi.ru/oct4/2007/ppt/02_17_Eric_Shassefiere.pdf Äàòà èçìåíåíèÿ: Tue Dec 4 17:09:16 2007 Äàòà èíäåêñèðîâàíèÿ: Fri Dec 21 22:07:25 2007 Êîäèðîâêà: Ïîèñêîâûå ñëîâà: ï ï ï ï ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï ð ï

T o w a r d a n i n te r n a ti o n a l V e n u s E x p l o r a ti o n P r o g r a m
E. ChassefiÕre Service d'AÈronomie/ IPSL
2 0 0 6 , V e n u s -E x p re s s , E u ro p e

1 9 6 7 - 1 9 8 5 , V e n e r a - V e g a, U S S R

1990, M a g e lla n , U S A

50 years of space era, Solar System Exploration symposium, 1-5 October 2007, Moscow


C o m p a r a ti v e s tu d y o f te r r e s tr i a l p l a n e ts

EARTH : Many feedback loops

MARS, VENUS : No more efficient regulation?

Figure from Breuer et al, 1986

Earth : greenhouse effect stabilized by interacting processes in the biosphere, atmosphere, hydrosphere, crust and mantle. Life can be seen as a geology-related process
E a r th c a r b o n a te s ilic a te c y c le

NOTION OF LIFE-GEOLOGY COEVOLUTION


Examples of important questions
Is there a feedback between life and tectonic style, atmosphere evolution, and ­ possibly­ magnetic field generation?


Is there a link between the failure to sustain plate tectonics and the loss of habitability? Is surface recycling on Venus similar to plate tectonics? What is the climate history of Mars and Venus? If there was once water on the surface of Venus, how fast was it lost? If Venus was dry how much atmosphere could have been lost over the planets history and under which conditions? Can massive abiotic oxygen amospheres be generated by runaway greenhouse on extrasolar planets?


C o n te x t fo r a c o m e b a c k to V e n u s ?
W h y d id V e n u s e v o lv e d d iffe r e n tly o f E a r th ? A n u r g e n t n e e d fo r a u n ifie d A w id e in te r e s te d in te r n a tio n a l s c ie n c e s c e n a r io o f te r r e s tr ia l p la n e t c o m m u n ity fo r m a tio n a n d e v o lu tio n A n o n g o in g p r o g r a m w ith th e E u r o p e a n A n e c e s s a r y s te p to w a r d V e X a n d th e J a p a n e s e V C O o r b ite r s e x tr a s o la r t e r r e s tr ia l p la n e t o b s e r v a tio n a n d m o d e llin g A te c h n ic a lly a n d s c ie n tific a lly h ig h r e tu r n - o n - in v e s tm e n t p la n e ta r y m is s io n re ly in g o n E S A , R o s c o s m o s , N A S A a n d J A X A e x p e rie n c e s

Need for an in situ mission to understand the evolution of Venus and its climate


European Venus Explorer
A proposed mission for ESA's Cosmic Vision 2015-2025
E. ChassefiÕre, O. Korablev, T. Imamura, K. Baines, C. Wilson (Co-PI), K. Aplin, T. Balint, J. Blamont, C. Cochrane, Cs Ferencz, F. Ferri, M. Gerasimov, J. Leitner, Lopez-Moreno, B. Marty, M. Martynov, S. Pogrebenko, A. Rodin, D. Titov, J. Whiteway, L. Zasova and the EVE team.


Why

?
(2 y e a rs )

(7 d a y s )

· · · · · ·

(1 h 3 0 )

Unified model of the formation and evolution of terrestrial planets Stability of the current climate Chemical/radiative processes in and below the clouds Geological history of Venus Atmospheric dynamics Electrical processes


M a i n s c i e n c e r e tu r n : i s o to p e s
I n s itu m e a s u r e m e n t f r o m th e b a llo o n o f n o b le g a s a b u n d a n c e s a n d s ta b le is o to p e r a tio s f r o m th e b a llo o n , to s tu d y th e r e c o r d o f th e e v o lu tio n o f V e n u s .
Venus isotopic ratios : Earth/Mars-like or solar-like?

F r o m P e p in a n d P o r c e lli , 2 0 0 2

Elemental ratios : Kr, Xe Earth/Mars-like, solar-like or chondritic-like? Why is Ne depleted?


M a i n s c i e n c e r e tu r n : c o m p o s i ti o n
In situ balloon-borne measurement of cloud particle and gas composition, and their spatial variation, to understand the complex cloud-level chemistry.
CO (35 km) : 20-30 ppm H2O (35 km) : 30 +/- 5 ppm COS & SO2 ....?

S P IC A V /S O IR

Detected molecules:
CO2, H2O, HDO, CO, HCl

: H2SO4 + ?

V IR T IS


M a i n s c i e n c e r e tu r n : d y n a m i c s

Lebonnois (personal communication, 2007)

I n s itu m e a s u r e m e n ts o f e n v ir o n m e n ta l p a r a m e te r s a n d w in d s ( f r o m tr a c k in g o f th e b a llo o n ) f o r o n e r o ta tio n a r o u n d th e planet (7 days), to understand atmospheric d y n a m ic s a n d r a d ia tiv e b a la n c e in th is c r u c ia l r e g io n .


B a llo o n s c i e n c e P /L

· · · · · · · ·

Composition of atmosphere and aerosol particles Microphysical properties of aerosol particles Isotopic ratios of noble gases, and of light elements Determination of local wind velocity, from tracking the balloon's position Upwards and downwards fluxes of radiation Electrical properties of atmosphere and clouds Cloud particles for exobiological potential Vertical profiles of radiative fluxes, pressure, temperature, and chemical abundances.
Mass (kg) 3.6 4.0 1.0 0.5 0.4 0.5 0.4 Power (W) 15W (peak) 15W (peak) 2W 1.2 W 2W 5W Data rate (bps ) 30 11.6 1.4 1.6 0.4 0.8 TRL Level/ heritage 4/5, Huygens, MSL, ExoMars, Phobos 4/5, Beagle2, Rosett a 3-4 4 5 Huygens, B eagle 2, Exo M a r s 8 6 Compass-2, ISS 4 including 21% margin Potential provider (laboratory, consortiu m ) IPSL (France), Open University (UK), IK I (Russia), others . Open Univ (UK) / IPSL (Fr) / U. Bern e ( C H ) NASA-led (Cornell/Ball A erospace) with TU Delft. Other possibility: IKI Univ. Oxford (UK) FMI (Finland) / Oxford U & Open U (UK) / Padova (Italy ) / IAA (Spain) / IWF (Au stria ) CNES (France) / TBD EÆtvÆs Univ (Hungary) & RAL (UK) IKI (with IFSI participation )

Instr u m e n t GC/MS with AC P Isotopic MS Nephelomete r Optical package Atmospheric package (p, T, acc, sound) VLBI beacon / USO Electrical / EM package ATR spectrometer TOTAL

Heritages Huygens,... Exomars

:

2.5 W 10.0 (peak) 2 5W 5 (peak) 12.4 kg w/o margin; o r 15 kg


D e s c e n t p ro b e s c i e n c e P /L

· · · · ·

A tm o s p h e r ic c h e m is tr y . C lo u d c h e m is tr y a n d o p tic a l p r o p e r tie s . A tm o s p h e r ic s tr u c tu r e , d y n a m ic s , a n d r a d ia tiv e b a la n c e . S u r f a c e c o m p o s itio n . A tm o s p h e r ic e le c tr ic a l p r o p e r tie s a n d E M w a v e phenom ena.
Mass (kg) 3.7 1.5 1 0.7 2 0.2 0.3 8 0.8 1.7 4 23.9 kg Russia, E U Power (W) <20 W 6W 2W 3W 5W 1W 2W 17W 2.3 W 5W D a t a rate (bit/s) 3 1.6 1.4 3+ 5 0.3 0.4 2 0.5 TR L (2007) 4-8 4 4 6 4 8 5-7 6-8 6 7 Origin IKI, IPSL, MPS, UK IKI, IPSL IKI, Inst Appl. Math. IKI IKI, IFS I IKI, TSNIIMASH IKI/ FM I IKI IKI, EÆtvÆs Univ IKI

Instrument Chemistry pack a g e Optical pack a g e Nephelomete r Imaging syste m ATR s pectromete r Acceleromete r

Heritages , ... Phobos BepiColombo

: Vega,

M eteorological package Gamma-spectromete r Lightning detec t o r OBD H 20% Ma r g i n Bud g e t :


O r b i te r s c i e n c e P /L

· · · · ·

Escape fluxes (mass spectrometers, magnetometer) Auroras (UV imager) Meso-thermospheric wind field (submm spectro + camera) Atmospheric composition (IR-submm spectro) Temperature profiles (radio science, in-situ, IR-submm spectro)
Instrume n t Neutral mass spec . Ion mass spec. M ass (kg ) 3 1.5 2.3 9.2 1.5 7.4 2.4 3.5 1 0.7 7.2 Power (W) 4 3-7 5 40 5 70 7 10 1 4-4 . 5 9 Data rat e (kb p s ) ~1 ~2 (!0.02) 6 ~ 9.2 40 4.8 4.4 < 10 0 ~4 " 80 TRL Level/ heri t a g e 4, Giotto, Cassini, BepiColombo 4, BepiColombo 6, Nozomi, BepiColombo 8/9, Rosetta, Herschel 9, MEX 4/9, Phoenix Mars 5, Mar s Express, Venus Express 6, ground based 9, in most o f mission s 7/5, Compass-2, ISS,... sw. BepiColombo 7/8, MEX, MRO and Exo M a r s 9, Oersted, Champ, Prob a2, Swarm ... 7/5, Coronas-F Potential p rovider (laboratory, consortium) IPSL (France ) Consortium: IK I (Russia), Mullard (UK) Tohoku Univ. (Japa n ) Max Planck Institute (Germany) Consortium: INAF (Italy), IKI (Russia) York Univ., MDA, CSA (Canada ) Consortium: IK I (Russia), INAF (Italy ) German A erospace Center (Germany) e.g General Dynamics (UK) Consortium: EÆtvÆs Univ., BL Electronics (Hungary) Consortium: IPG, Obs. Midi-PyrÈnÈes & de Bordeaux (France), GSFC, JPL and UTA (USA ) Dan. Nat. Space C enter (Danemark), Imperial College London (UK) Consortium: IK I, SINP MSU (Russia) ESA (& ECS), Russia, USA, Japan, C a n a d a




BES RO R P OAD O L EF NC PAY AL CIE TS BIT X R NTE WO E CO TN OS LM A

UV plasma image r Sub-mm sounde r UV mapping spectrometer Lidar (TBC) Infrared Spectrometer High-speed / context camer a USO for radio scienc e EM Wave analy ser Subsurface Radar Magnetomete r Gamma Flash Detector 20% margin Tot a l :

· · ·

Electric activity (gamma, visible, radio emissions, insitu) Cloud structure (lidar, camera, IR spectro, in-situ) Subsurface structure (radar)

" 1.2 2.3 8.6 51.8

1.2 3 ! 170

1.5 10 210


M is s io n b a s e lin e
Departure date Departure conditions Arrival date Arrival relative velocity Cruise duration 2016 (nominal) 8.12.2016 v = 3.38km/s = 32deg 18.05.2017 2.68 km/s 161 days 2018 (backup) 10.06.2018 v = 3.93km/s = -39d eg 11.12.2018 2.99 km/s 184 days


T e l e c o m m u n i c a ti o n s tr a te g y

Back-up option : direct Balloon-toEarth downlink

Aper t u r e Frequency range (MHz) Aperture efficienc y SNR (in 1 Hz) M a x . d a t a rate ( b p s ) Aver. Data rate (bps) TR L ( 2 0 0 7 )

We s t b r o c k 14 x 25m 300-450 0.35 35 20 !2 8

Effelsberg 100 m 350-450 0.6 110 6 !7 8

Green Bank 100 m 300-500 0.6 270 150 !20 8

Me d i c i n a 30,000 m2 406-410 0.4 230 130 !15 8

Arec i b o 300 m 425-435 0.4 1100 600
SKA=30% 300,000 m2 300-500 0.4 3500 2000 !200 3

D a ta r a te a c h ie v a b le b y U H F t r a n s m is s io n f r o m b a llo o n ( o r d e s c e n t p r o b e ) d ir e c t t o E a r th


B a llo o n p ro b e
O p tio n 1 : S u p e r p r e s s u r e b a llo o n

O p tio n 2 : P h a s e c h a n g e o s c illa tin g b a llo o n
He

v a por

He

H2O liquid

Scientifically attractive option but less mature design

H2O

S uspen ded mass

CNES Venera super pressure balloon (1970 ­ 1980)

Suspen ded mass

M ASS BUDGET C N E S c a lc u la tio n s
Sub syst e m Gondola Mass (kg) 40 17 23 90 170 Comm e n t s Includes 15 kg of scientific instrum e n t s Includes 10 kg of envelop and 7 kg of H e Based on He g as tank. Parachute, inner structure, back cover

Overall b alloon mass ( k g ) Suspended mass (kg) Balloon envelop mass ( k g ) Balloon r adius (m) Over-pressure (hP a )

5 4 1 2 1

7.0 0.0 0.0 .5 00

Bal l o o n Gas storage system Russian Entry System Total


E V E i n te r n a ti o n a l c o o p e r a ti v e s c h e m e
· EUROPE
­ T h e s p a c e c r a f t, ­ th e b a llo o n p la tf o r m a n d ­ th e K o u r o u e le m e n t o f th e la u n c h c o s ts .

· JAPAN
­ A s m a ll b a llo o n f o r lo w a ltitu d e s tu d ie s ( o p tio n ) .

· USA & CANADA
­ C o m p r e h e n s iv e s c ie n c e a n d in s tr u m e n t h a r d w a r e in v o lv e m e n ts a n d ­ p o s s ib ility o f u s in g N A S A /J P L d e v e lo p e d V e n u s b a llo o n te c h n o lo g y th r o u g h in te r n a tio n a l c o lla b o r a tio n , u n d e r N A S A 's M is s io n o f O p p o r tu n ity ( M o O ) p ro g ram .

· RUSSIA
­ T h e d r y S o y u z la u n c h e r , ­ th e d e s c e n t p r o b e , ­ th e e n tr y /d e s c e n t s y s te m s f o r b o th b a llo o n a n d d e s c e n t p ro b e an d ­ A c o n tr ib u tio n to th e s c ie n c e p a y lo a d a n d d a ta a n a ly s is .


A s te p - b y - s te p i n te r n a ti o n a l p r o g r a m to V e n u s
· Step 1 (2000-2010) : Orbiter missions (VEx and VCO) atmospheric and cloud dynamics · Step 2 (2010-2020) : Balloon/descent probe mission (EVE?) evolution, chemistry and general dynamics · Step 3 (2020-2030) : Longliving landers/low atmosphere platforms interior structure/dynamics and coupling to the climatic system Venus Express (Europe) Venus Climate Orbiter (Japan) EVE (Europe/Russia) Low H2O balloon (Japan) VENERA-D (Russia + others) Flagship mission (NASA + others)