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European Venus Explorer (EVE)

Cosmic Vision Class M (<300M)
29 2007


?
· :
­ Venus Express

·

(-):

­ ­ 15-16 Magellan, ­ -


Scientific Objectives for EVE
1) Determination of isotopic composition, especially that of noble gases, which preserves a record of the origin and evolution of Venus. 2) Measurements of atmospheric composition at cloud level, and below the clouds. 3) In-situ investigation of the dynamics, structure, and radiative balance of the atmosphere. 4) Study of composition and optical properties of the cloud layer at different altitudes and locations. 5) Investigation of the surface composition and mineralogy, and near-surface atmosphere chemistry, at several locations representing the main types of Venus landforms. 6) Characterization of Venus' electrical environment, including search for lightning. 7) Characterization of solar wind - atmosphere interaction processes and measurement of atmospheric escape.


EVE:
· : -2-1- Kourou
­

·
­ ()
· 170 kg entry mass

­ High Balloon (ESA)
· 170 kg entry mass

­ Optionally: Low balloon (Japan)
· 35 kg entry mass


Geometric configuration
Insertion orbit : 250/66000 km Period = 1 day Inclination : 90° Periapsis node : ~ - 30°

Sequence :
· · · · · · · · Arrival Vinf = 3 km/s Entry probe 1 separation T0 ­ 7 days Entry probe 2 separation T0 ­ 5 days Orbiter acceleration DV = 50 m/s Probe entry T0 +3 h Balloon/orbiter comm : T0 -3h to T0-1h Periapsis insertion manoeuver : T0-1h to T0+1h Balloon/orbiter comm : from T0 +1h

70° N

25° N

~ 30°

Calculations & figure courtesy of J. Michaud (CNES)


EVE ­ main balloon
· There are two possibilities for balloon: · Option 1: Balloon oscillates in range 40 ­ 60 km
­ T = -10 to 140 єC ­ NH3/H2O ­ Multiple vertical profiles through clouds

· Option 2: Balloon has `constant' 55 ± 10 km altitude
­ ­ ­ ­ Helium or hydrogen-filled Less technological risk Stable temperature is good for isotopic MS Better conditions to study the UV absorber or lower clouds


EVE: balloon floating at 55 km
Instrument GC/MS & ACP Isotopic MS Nephelometer Optical package Met. package (p, T, acc) VLBI S-band beacon ATR aerosol spectrometer TOTAL Mass (kg) 3.05 4.0 2.3 0.5 0.3 0.5 2.0 15.15 Power (W) 15 W (peak) 15 W (peak) 2W 1.2 W 2 4 5 W (peak) 0.1 W (average) Data rate (bits/s) 30 11.6 1.4 1.6 0.8 0 5 50.8 TRL (2007) 4/5 4/5 4 4+ 4/5 8 4 Origin Service d'Aeronomie (F), Open U (UK), IKI (RU) Open U., Service d'Aeronomie, U. Berne (CH) Cornell (USA), TU Delft (NL) Oxford U (UK) FMI (FI), Oxford U., Open U., Padova (I). CNES IKI, IFSI (I) EU, Russia, USA


VENUS

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January 11th, 2007

Orbiter Design Approach
based on Venus Express heritage :


Orbiter payload
· · · · · · · · · · · · · · Sub-mm spectrometer (SWI) IR spectrometer (MIMA-V) Lidar (OLIVE) UV mapping spect. (UVMS) Ultra-stable oscillator (USO) Penetrating radar (VISRS) Magnetometer (SGVM) Gravity field (transponder) Neutral MS (NMES) Ion MS (LEIMS/ PICAM) EMW analyzer (SAS2-VSN) Meteor/UV Camera (SPOSH) Gamma-ray burst detector IR spectral imager MPI IFSI/IKI IK/ISIF Canada Science to better define IFSI/IKI Koeln IPGP/USA DTU Uncertain science Obs. Belgium Science under evaluation IPSL IKI Eotvos DLR To be reduced (<1 kg) Moscow U. New, science TBD IFSI/IKI Combine with MIMA?

·

Total mass <35 kg



· · · · 170 25 ~65 15-30



Instrument Chemistry package Optical package Nephelometer Imaging system ATR spectrometer Accelerometer Meteorological package Gammaspectrometer Permittivity probe, lightning detector Budget: Mass (kg) 3.7 Power (W) 20 W (peak) Data rate (kbit/s) 3 TRL (2007) 4-8 Origin IKI (RU), Service d'Aeronomie (F), MPS (D), Open U. (UK) IKI, Service d'Aeronomie IKI, Inst Appl. Math (RU). IKI IKI, IFSI (I) IKI, TSNIIMASH (RU), Padova (I) IKI, FMI (FI), Padova IKI IKI, EЖtvЖs U. (Hun), IAA (E)

1.5 1 0.7 2 0.2 0.3 8 1

6W 2W 3W 5W 1W 2W 17W 2.4W

1.6 1.4 10-30 5 0.3 0.4 2 0.5

4 4 6 4 8 5-7 6-8 5-6

24 kg

Russia, EU


EVE
· (-2-1 Kourou) ·
­

· · ( )


-
· 2003: .. 2006-2015. · 2005: - 2006-2015 2015


EVE

-

· EVE
­ ­ , ­ (

· -