VENUS EXPRESS. The First European Mission to Venus. Gerhard Schwehm and Hakan Svedhem ESA/ESTEC

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1 VENUS EXPRESS The First European Mission to Venus Gerhard Schwehm and Hakan Svedhem ESA/ESTEC

2 Why is ESA going to Venus? Venus is a fascinating planet and an attractive target for planetary sciences : 1 st phase of Venus Exploration: Basic understanding on condition of the planet Radar mapping of the surface Great number of unsolved problems Good opportunity with the call of ideas released by ESA in 2001 concerning the reuse of the Mars Express design. Title : Page 2

3 Venus questions: How does the global dynamics of the planet work? What is driving the super-rotation? How is the polar double vortex maintained? What is the global thermal balance of the planet? What role does the greenhouse effect play in the past, present and in the future? How does the cloud system work? What is the behaviour and the characteristics of the clouds and the hazes at the different levels? What is the origin of the UV markings above the clouds? What is the evolution of the atmosphere of the planet? What are the escape processes, evolution of water? What is the origin of the highly radar reflective areas on the surface? Is there presently volcanic or seismic activity on the planet? Title : Page 3

4 2001: Call for ideas to re-use the Mars Express spacecraft Minor modifications to the Mars Express spacecraft (smaller solar panels and HGA, thermal design) Use existing scientific payload Readiness for launch in 2005 Title : Page 4

5 Venus Express Spacecraft Title : Page 5

6 Major S/C characteristics Box like structure 1.7 x 1.7 x1.4 m Max launch mass 1270 kg Available solar power Venus 3 x 24 Ah Li-Ion Batteries Telemetry link kbps Mass memory 12Gbit 400 N main engine, 2 x 4 x 10N thrusters Title : Page 6

7 Venus Express mission goal Global investigation of the Venus atmosphere, plasma environment, and some important aspects of geology and surface physics from orbit Title : Page 7

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17 Venus Express Orbit Characteristics 24 hours period km pericentre altitude km apocentre altitude 90 deg inclination Pericentre latitude ~80 deg N 7-10 hours communication link per orbit Title : Page 17

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20 Venus Express payload PFS (V. Formisano) - high resolution IR Fourier spectrometer SPICAV / SOIR (J.-L. Bertaux) -UV & IR spectrometer for solar/stellar occultations and nadir observations VIRTIS (P. Drossart, G. Piccioni) - UV-vis-near IR imaging and high resolution spectrometer VMC (W.J. Markiewicz) - Venus Monitoring Camera VeRa (B. Häusler) - radio science experiment ASPERA (S. Barabash) - Analyzer of Space Plasmas and Energetic Atoms MAG (T. Zhang) Magnetometer Title : Page 20

21 Venus Express payload ASPERA S. Barabash, IRF Kiruna (SE) VIRTIS P. Drossart, Obs. Meudon (FR) G. Piccioni, CNR-IASF (IT) VeRA B. Häusler, Univ.BW München (DE) PFS V. Formisano, CNR Rome (IT) MAG T. Zhang, OAW Graz (AT) SPICAV J-L.Bertaux, CNRS Verrières (FR) VMC W. Markiewicz, MPAe Lindau (DE) Title : Page 21

22 ASPERA ASPERA will investigate the interaction between the solar wind and the atmosphere of Venus by measuring outflowing particles from from both the planet s atmosphere and the solar wind. Principal Investigator: Stas Barabash, Institute of Space Physics, Kiruna, Sweden Heritage: Mars Express Title : Page 22

23 PFS PFS will be able to measure the temperature of the atmosphere between 55 and 100 km of altitude at very high resolution. It will also measure surface temperature, looking for volcanic activity. The instrument will be able to make compositional measurements of the atmosphere Principal Investigator: Vittorio Formisano, IFSI-CNR, Rome, Italy Heritage: Mars Express Title : Page 23

24 SPICAV SPICAV will determine the density and temperature of the atmosphere between 80 and 180 kilometres of altitude. It will search for small quantities of water, sulphur compounds and molecular oxygen in the atmosphere of Venus Principal Investigators: Jean-Loup Bertaux, Service d Aeronomie du CNRS, France Heritage: Mars Express Title : Page 24

25 VIRTIS VIRTIS will be able to study the composition of lower atmosphere, below the cloud decks at kilometres altitudes. It will track clouds in both ultraviolet and infrared wavelengths, in order to study atmospheric dynamics at various altitudes. Principal Investigators: Pierre Drossart, Observatoire de Paris, France Giuseppe Piccioni, CNR IASF, Rome, Italy Heritage: Rosetta Title : Page 25

26 MAG MAG will measure the magnetic field around the planet induced by the interaction between the solar wind and the atmosphere.it will help understanding its effect on Venusian atmosphere. Principal Investigator: Tielong Zhang, IWF, Graz, Austria Heritage: NEW, design from Rosetta lander Title : Page 26

27 VMC VMC is a wide-angle multi-channel camera that will take pictures at near infrared, ultraviolet and visible wavelengths. It will be able to produce global images and study cloud dynamics and image the surface. It will also assist other instruments in the identification of phenomena. Principal Investigator: Wojciech Markiewicz. MPI-Ae, Katlenburg,-Lindau, Germany Heritage: NEW Title : Page 27

28 VERA VERA uses the radio link between the spacecraft and Earth to incestigate the ionosphere of Venus. It will allow the study of density, temperature, pressure of the atmosphere at altitudes of kilometres. It will also characterize the solar wind in the inner Solar System. Principal Investigator: Bernd Hausler, U. der Bunderswehr, Munchen, Germany Heritage: Mars Express Title : Page 28

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31 Fields of view of the instruments at a distance of km Title : Page 31

32 Synergy of the instruments on Venus Express Title : Page 32

33 Venus Express Science Themes Structure of the atmosphere Atmospheric composition and chemistry Dynamics of the atmosphere Radiative balance Plasma environment and escape processes Surface properties and geology Title : Page 33

34 Structure of the atmosphere PFS, VIRTIS, SPICAV, VeRa/ Title : Page 34

35 Atmospheric composition Composition and structure of the upper atmosphere: SPICAV / SOIR Composition of the mesosphere: PFS, VIRTIS, SPICAV, VMC Title : Page 35

36 Dynamics of the atmosphere VIRTIS spectral mapping VMC global imaging PFS thermal wind field 3-D time variable picture of the atmospheric dynamics Title : Blue : 70 km NIR: 50 km UV: UV >100 km Page 36

37 Plasma environment and escape processes ASPERA and MAG Global plasma and neutral gas distribution and velocities Magnetic field measurements Solar wind - atmosphere interaction Study of escape processes SPICAV/SOIR Neutral atmosphere up to 180 km VERA Ionosphere up to 600 km Title : Page 37

38 Surface properties and geology Radio science Bi-static sounding Gravity anomalies Imagers Thermal mapping at ~1 m Search for active volcanism Spectrometers Composition of the lower atmosphere Search for Venus-quakes Title : Page 38

39 Latest News Launch confirmed for 9 November 2005, 3:33 UTC Title : Page 39

40 Planet Venus Second from the Sun, 0.72 of Earth-Sun distance Pioneer Venus R Venus = 6052 km = 0.95 R Earth M Venus = 4.87 x kg = M Earth Magellan g Venus = 8.87 m/s 2 = 0.91 g Earth Title : Page 40

41 Views of Venus surface Title : Page 41

42 Venus Express science objectives Goal: to carry out a comprehensive study of the atmosphere of Venus and to study to some detail the plasma environment and number of aspects of the surface of the planet. Focus today on: Study of the greenhouse effect Atmosphere sounding Venus surface Key question: Why has Venus evolved in such a different way compared to the Earth despite the many similarities? Title : Page 42

43 Radiative balance Title : Page 43