View source for Venus Express

{{Short description|European orbiter mission to Venus (2005–2015)}}

{{italic title}}

{{Use dmy dates|date=October 2021}}

{{Use British english|date=November 2025}}

{{Infobox spaceflight
| name                  = ''Venus Express''
| image                 = Venus Express in orbit (crop).jpg
| image_size            = 300px
| image_caption         = ''Venus Express'' in orbit

<!--Basic details-->
| mission_type          = [[Venus]] orbiter
| operator              = [[European Space Agency]]
| COSPAR_ID             = 2005-045A
| SATCAT                = 28901
| website               = {{url|http://www.esa.int/venus}}
| mission_duration      = Planned: 2 years <br/> Final: {{time interval|9 Nov 2005|18 Jan 2015|sep=,}}

<!--Spacecraft properties-->
| manufacturer          = [[EADS Astrium]]
| launch_mass           = {{convert|1270|kg|lb|0|abbr=on}}<ref name="factsheet">{{cite web |url=http://www.esa.int/Our_Activities/Space_Science/Venus_Express/Venus_Express_factsheet |title=Venus Express Factsheet |publisher=European Space Agency |date=1 June 2014 |access-date=5 July 2017}}</ref>
| dry_mass              = {{cvt|700|kg|lb}}<ref name="factsheet" />
| payload_mass          = {{cvt|93|kg|lb}}<ref name="factsheet" />
| dimensions            = {{convert|1.5|xx|1.8|xx|1.4|m|ft|abbr=on}}<ref name="factsheet" />
| power                 = 1,100 watts<ref name="factsheet" />

<!--Launch details-->
| launch_date           = {{start-date|9 November 2005, 03:33:34}}&nbsp;[[UTC]]<ref name=VEX>{{cite book|url=https://www.nasa.gov/sites/default/files/atoms/files/beyond-earth-tagged.pdf|title=Beyond Earth: A Chronicle of Deep Space Exploration, 1958–2016|last1=Siddiqi|first1=Asif|publisher=NASA History Program Office|edition=second|year=2018}}</ref>
| launch_rocket         = [[Soyuz-FG]]/[[Fregat]]
| launch_site           = [[Baikonur Cosmodrome|Baikonur]] [[Baikonur Cosmodrome Site 31|31/6]]
| launch_contractor     = [[Starsem]]

<!--end of mission-->
| disposal_type         = Deorbited
| last_contact          = {{end-date|18 January 2015, 15:01:55}}&nbsp;[[UTC]]<ref name="esa20150123">{{cite web |last1=Scuka |first1=Daniel |title=Venus Express: The Last Shout |url=http://blogs.esa.int/rocketscience/2015/01/23/venus-express-the-last-shout/ |publisher=European Space Agency |date=23 January 2015 |access-date=26 January 2015}}</ref>
| decay_date            = January{{\}}February 2015

<!--orbit parameters-->
| orbit_reference       = [[cytherocentric orbit|Cytherocentric]]
| orbit_semimajor       = 
| orbit_eccentricity    = 
| orbit_periapsis       = {{convert|460|km|abbr=on}}<ref name="vex-venturing">{{cite web |url=http://sci.esa.int/venus-express/54915-venturing-into-the-upper-atmosphere-of-venus/ |title=Venturing into the upper atmosphere of Venus |publisher=European Space Agency |date=11 November 2014 |access-date=23 November 2014}}</ref>
| orbit_apoapsis        = {{convert|63000|km|abbr=on}}<ref name="vex-venturing"/>
| orbit_inclination     = 90&nbsp;degrees<ref name="vex-oporbit">{{cite web |url=http://sci.esa.int/venus-express/37357-operational-orbit/ |title=Operational Orbit |publisher=European Space Agency |date=14 December 2012 |access-date=23 November 2014}}</ref>
| orbit_period          = 24 hours<ref name="vex-oporbit"/>
| apsis                 = cytherion

|interplanetary         = 
 {{Infobox spaceflight/IP
   |type                = orbiter
   |object              = [[Venus]]
   |arrival_date        = 11 April 2006
 }}

| insignia              = File:Venus Express insignia.png
| insignia_caption      = ESA Solar System insignia for the ''Venus Express'' mission
| insignia_alt          = Venus Express mission insignia
| insignia_size         = 180px
}}

'''''Venus Express''''' ('''VEX''') was the first [[Venus]] exploration mission of the [[European Space Agency|European Space Agency (ESA)]]. Launched in November 2005, it arrived at Venus in April 2006 and began continuously sending back science data from its polar orbit around Venus. Equipped with seven scientific instruments, the main objective of the mission was the long term observation of the [[Venusian atmosphere]]. The observation over such long periods of time had never been done in previous missions to Venus, and was key to a better understanding of the atmospheric dynamics. ESA concluded the mission in December 2014.<ref name="esa20141216">{{cite web |url=http://www.esa.int/Our_Activities/Space_Science/Venus_Express/Venus_Express_goes_gently_into_the_night |title=Venus Express goes gently into the night |publisher=European Space Agency |first1=Markus |last1=Bauer |first2=Håkan |last2=Svedhem |first3=Adam |last3=Williams |first4=Patrick |last4=Martin |date=16 December 2014 |access-date=22 December 2014}}</ref><ref>{{Cite web |title=Venus Express - Venus |url=https://venus.wisc.edu/missions/venus-express/ |access-date=2025-11-20 |language=en-US}}</ref><ref>{{Cite web |last=admin |date=2018-08-06 |title=Venus Express {{!}} Faculty of Mathematical & Physical Sciences |url=https://www.ucl.ac.uk/mathematical-physical-sciences/research-projects/2018/aug/venus-express |access-date=2025-11-20 |website=www.ucl.ac.uk |language=en}}</ref><ref>{{Cite web |date=2025-11-20 |title=Out of Fuel, Venus Express Is Falling Gently to Its Death in Planet's Skies |url=https://www.nationalgeographic.com/science/article/141217-venus-express-final-plunge-space-science |access-date=2025-11-20 |website=Science |language=en}}</ref>

[[File:11214 2023 956 Fig10 HTML.webp|thumb|310x310px|Orbits and trajectories of [[Mariner 2|''Mariner 2'']], [[Venera 4|''Venera 4'']], [[Pioneer Venus Orbiter|''Pioneer Venus Orbiter'']], and ''Venus Express'']]
[[File:Animation of Venus Express trajectory.gif|thumb|Animation of ''Venus Express''{{'s}} trajectory from 9 November 2005 to 31 December 2006<br />{{legend2|magenta|''Venus Express''}}{{·}}{{legend2|Lime|Venus}}{{·}}{{legend2|RoyalBlue|Earth}}{{·}}{{legend2|Yellow|Sun}}|310x310px]]
[[File:Animation of Venus Express trajectory around Venus.gif|thumb|Animation of ''Venus Express''{{'s}} trajectory around Venus from 1 April 2006 to 1 April 2008<br />{{legend2|magenta|''Venus Express''}}{{·}}{{legend2|Lime|Venus}}|310x310px]]
[[File:Venus - ESA Venus Express (53672036164).png|thumb|Venus, May 2006|310x310px]]
[[File:Catastrophe from the Clouds (2963973027).jpg|thumb|Ultraviolet picture (with arbitrary color) of Venus. The clouds betray the extremely fast winds at mid levels of the atmosphere, which circumnavigate the globe in just four days, August 2008|310x310px]]
[[File:Unfriendly Neighbor (2780983089).jpg|thumb|Ultraviolet picture colored to draw out highlights in the clouds, August 2008|310x310px]]
[[File:Hot Wind (2873188820).jpg|thumb|The daylight side shown in visible light and the night side in infrared, September 2008|310x310px]]
[[File:The Evening Star a Double Take (2859183621).jpg|thumb|On the left is what the planet looked like in visible light: a nearly featureless orb of highly-reflective clouds. On the right is a shot taken at about the same time through a filter sensitive to ultraviolet light, which the human eye can't see, September 2008|310x310px]]
[[File:The Evening Star in a New Light (3083434398).jpg|thumb|Venus in infrared (here as red) and ultraviolet light by ''Venus Express'', December 2008|310x310px]]

==Objectives==
Starting out in the early planetary system with similar sizes and chemical compositions, the histories of [[Venus]] and [[Earth]] have diverged in spectacular fashion. The ''Venus Express'' data were intended to contribute not only to in-depth understanding of how the [[Atmosphere of Venus|Venusian atmosphere]] is structured today, but also to understanding of the changes that led to the current [[Greenhouse effect|greenhouse]] atmospheric conditions. Such investigations contribute to the study of [[climate change]] on Earth.<ref>{{cite web |title=Atmospheric Dynamics of Venus and Earth |url=http://www.lpi.usra.edu/vexag/nov_2007/presentations/schubert.pdf |access-date=15 December 2014 |publisher=Lpi.usra.edu}}</ref><ref>{{Cite web |title=Venus Express, a Venusian atmosphere mission |url=https://www.aeronomie.be/en/encyclopedia/venus-express-venusian-atmosphere-mission |access-date=2025-11-20 |website=Royal Belgian Institute for Space Aeronomy |language=en}}</ref><ref>{{Cite web |date=2024-07-11 |title=What did ESA's Venus Express mission discover? |url=https://www.skyatnightmagazine.com/space-missions/what-did-venus-express-mission-discover |access-date=2025-11-20 |website=BBC Sky at Night Magazine |language=en}}</ref><ref>{{Cite web |last=Cain |first=Fraser |date=2006-07-12 |title=Science Updates from Venus Express |url=https://www.universetoday.com/articles/science-updates-from-venus-express |access-date=2025-11-20 |website=Universe Today |language=en}}</ref>

==Instruments==
'''ASPERA-4''': An acronym for "'''A'''nalyzer of '''S'''pace '''P'''lasmas and '''E'''ne'''r'''getic '''A'''toms," ASPERA-4 investigated the interaction between the [[solar wind]] and the Venusian atmosphere, determine the impact of plasma processes on the atmosphere, determine global distribution of plasma and neutral gas, study energetic neutral atoms, ions and electrons, and analyze other aspects of the near Venus environment. ASPERA-4 is a re-use of the ASPERA-3 design used on ''Mars Express'', but adapted for the harsher near-Venus environment.<ref>{{Cite web |title=Max Planck Institute for Solar System Research |url=https://www2.mps.mpg.de/en/projekte/venus-express/aspera4/ |access-date=2025-11-20 |website=www2.mps.mpg.de}}</ref><ref>[https://sci.esa.int/documents/34571/36233/1567259597731-asperaWeb.pdf ASPERA-4: Analyser of Space Plasmas and Energetic Atoms]</ref>

'''MAG''': The [[magnetometer]] was designed to measure the strength of Venus's magnetic field and the direction of it as affected by the solar wind and Venus itself. It mapped the [[magnetosheath]], [[magnetosphere|magnetotail]], [[ionosphere]], and magnetic barrier in high resolution in three-dimensions, aid ASPERA-4 in the study of the interaction of the solar wind with the atmosphere of Venus, identify the boundaries between plasma regions, and carry planetary observations as well (such as the search for and characterization of Venus lightning). MAG was derived from the ''Rosetta'' lander's ROMAP instrument.<ref name=":1">[https://sci.esa.int/documents/34571/36233/1567256675388-MagWeb.pdf MAG: The Fluxgate Magnetometer of Venus Express]</ref><ref name=":2">{{Cite web |last=Braunschweig |first=Technische Universität |title=Venus Express |url=https://www.tu-braunschweig.de/en/igep/research/venus-express |access-date=2025-11-20 |website=www.tu-braunschweig.de |language=en}}</ref>

One measuring device was placed on the body of the craft. The identical second of the pair was placed the necessary distance away from the body by unfolding a {{convert|1|m|ft|abbr=on|adj=mid|-long}} boom (carbon composite tube). Two redundant pyrotechnical cutters cut one loop of thin rope to free the power of metal springs. The driven knee lever rotated the boom perpendicularly outwards and latched it in place. Only the use of a pair of sensors together with the rotation of the probe allowed the spacecraft to resolve the small natural magnetic field beneath the disturbing fields of the probe itself.<ref name=":1" /><ref name=":2" /> 

The measurements to identify the fields produced by the craft took place on the route from Earth to Venus.<ref>{{cite web |url=http://www.iwf.oeaw.ac.at/de/forschung/sonnensystem/planeten/venus/venus-express/vex-mag/ |title=IWF : VEX-MAG |publisher=Iwf.oewa.ac.at |access-date=15 December 2014 |archive-date=6 October 2014 |archive-url=https://web.archive.org/web/20141006164723/http://www.iwf.oeaw.ac.at/de/forschung/sonnensystem/planeten/venus/venus-express/vex-mag/ |url-status=dead}}</ref><ref name="pope639">{{cite journal |title=Exploring planetary magnetic environments using magnetically unclean spacecraft: A systems approach to VEX MAG data analysis |journal=Annales Geophysicae |last1=Pope |first1=S. A. |last2=Zhang |first2=T. L. |last3=Balikhin |first3=M. A. |last4=Hvizdos |first4=L. |last5=Kudela |first5=K. |last6=Dimmock |first6=A. P. |volume=29 |issue=4 |pages=639–647 |date=April 2011 |doi=10.5194/angeo-29-639-2011 |bibcode=2011AnGeo..29..639P|doi-access=free }}</ref> The lack of magnetic cleanness was due to the reuse of the ''[[Mars Express]]'' spacecraft bus, which did not carry a magnetometer.<ref name="pope639" /> By combining the data from two-point simultaneous measurements and using software to identify and remove interference generated by ''Venus Express'' itself, it was possible to obtain results of a quality comparable to those produced by a magnetically clean craft.<ref name="pope639" />

'''VMC''': The '''V'''enus '''M'''onitoring '''C'''amera is a wide-angle, multi-channel [[Charge-coupled device|CCD]]. The VMC is designed for global imaging of the planet.<ref>{{cite web |url=http://www.mps.mpg.de/en/projekte/venus-express/vmc/ |title=The Venus Express mission camera |publisher=Max Planck Institute for Solar System Research |url-status=dead |archive-url=https://web.archive.org/web/20080307024329/http://www.mps.mpg.de/en/projekte/venus-express/vmc/ |archive-date=7 March 2008 }}</ref> It operated in the visible (VIS), ultraviolet (UV), and near infrared (NIR1 and NIR2) spectral ranges, and maps surface brightness distribution searching for volcanic activity, monitoring [[airglow]], studying the distribution of unknown ultraviolet absorbing phenomenon at the cloud-tops, and making other science observations.<ref>{{Cite journal |last=Markiewicz |first=W. J. |last2=Titov |first2=D. V. |last3=Ignatiev |first3=N. |last4=Keller |first4=H. U. |last5=Crisp |first5=D. |last6=Limaye |first6=S. S. |last7=Jaumann |first7=R. |last8=Moissl |first8=R. |last9=Thomas |first9=N. |last10=Esposito |first10=L. |last11=Watanabe |first11=S. |last12=Fiethe |first12=B. |last13=Behnke |first13=T. |last14=Szemerey |first14=I. |last15=Michalik |first15=H. |date=2007-10-01 |title=Venus Monitoring Camera for Venus Express |url=https://www.sciencedirect.com/science/article/pii/S0032063307000086 |journal=Planetary and Space Science |series=The Planet Venus and the Venus Express Mission, Part 2 |volume=55 |issue=12 |pages=1701–1711 |doi=10.1016/j.pss.2007.01.004 |issn=0032-0633}}</ref><ref>{{Cite web |title=Max Planck Institute for Solar System Research |url=https://www2.mps.mpg.de/en/projekte/venus-express/vmc/ |access-date=2025-11-20 |website=www2.mps.mpg.de}}</ref><ref>{{Cite web |title=VMC |url=https://www.ida.ing.tu-bs.de/en/research/group-michalik/data-processing-units-for-space-applications/vmc |access-date=2025-11-20 |website=www.ida.ing.tu-bs.de}}</ref> 

It was derived in part from the ''Mars Express'' [[High Resolution Stereo Camera|High Resolution Stereo Camera (HRSC)]] and the ''Rosetta'' [[Optical, Spectroscopic, and Infrared Remote Imaging System|Optical, Spectroscopic and Infrared Remote Imaging System (OSIRIS)]]. The camera is based on a Kodak KAI-1010 Series, 1024 x 1024 pixel interline CCD, and included an [[FPGA]] to pre-process image data, reducing the amount transmitted to Earth.<ref name=":0" /><ref>{{cite web |url=http://www.ida.ing.tu-bs.de/index.php?id=841&L=2. |title=Venus Monitoring Camera |publisher=Technical University at Brunswick}}</ref> 

The consortium of institutions responsible for the VMC included the [[Max Planck Institute for Solar System Research]], the Institute of Planetary Research at the [[German Aerospace Center]] and the Institute of Computer and Communication Network Engineering at [[Technische Universität Braunschweig]].<ref>{{cite web |url=http://www.esa.int/esaCP/SEMIVTVHJCF_index_0.html |title=The light and dark of Venus |date=21 February 2008 |publisher=ESA}}</ref> It is not to be confused with [[Visual Monitoring Camera]] mounted on ''[[Mars Express]]'', of which it is an evolution.<ref name=":0">{{cite web |url=https://www.mps.mpg.de/2416908/VMC-Dokumentation.pdf |title=Venus Monitoring Camera for Venus Express |publisher=Max Planck Institute for Solar System Research |first1=W. J. |last1=Markiewicz |first2=D. |last2=Titov |first3=B. |last3=Fiethe |first4=T. |last4=Behnke |first5=I. |last5=Szemerey |first6=H. |last6=Perplies |first7=M. |last7=Wedemeier |first8=I. |last8=Sebastian |first9=W. |last9=Boogaerts |first10=C. |last10=Dierker |first11=D. |last11=Osterloh |first12=N. |last12=Ignatiev |first13=M. |last13=Koch |first14=H. U. |last14=Keller |first15=R. |last15=Jaumann |first16=H. |last16=Michaelis |first17=H. |last17=Michalik |first18=D. |last18=Crisp |first19=L. |last19=Esposito |first20=S. S. |last20=Limaye |first21=S. |last21=Watanabe |first22=N. |last22=Thomas |first23=D. |last23=Belyaev |first24=A. |last24=Dannenberg |first25=M. |last25=Tchimmel |first26=R. |last26=Moissl |display-authors=5 |url-status=dead |archive-url=https://web.archive.org/web/20150402104722/https://www.mps.mpg.de/2416908/VMC-Dokumentation.pdf |archive-date=2 April 2015 }}</ref><ref>{{cite web |url=http://www.lpi.usra.edu/vexag/mission_definition.pdf |title=Venus Express: Mission Definition Report |publisher=European Space Agency |first1=Ch. |last1=Koeck |first2=S. |last2=Kemble |first3=L. |last3=Gautret |first4=P. |last4=Renard |first5=F. |last5=Faye |page=17 |date=October 2001 |id=ESA-SCI(2001)6}}</ref>
{| class="wikitable"
|+'''V'''enus '''M'''onitoring '''C'''amera channels<ref name=":0" />
!VMC Channel
!Central Wavelength
!Spectral Range
|-
|VIS
|513 nm
|503 – 523 nm
|-
|NIR1
|935 nm
|900 – 970 nm
|-
|NIR2
|1.01 μm
|990 – 1030 nm
|-
|UV
|365 nm
|345 – 385 nm
|}

'''PFS''': The "'''P'''lanetary '''F'''ourier '''S'''pectrometer" (PFS) should have operated in the [[infrared]] between the 0.9&nbsp;[[micrometre|μm]] and 45&nbsp;μm wavelength range and was designed to perform vertical optical sounding of the Venus atmosphere. It should have performed global, long-term monitoring of the three-dimensional temperature field in the lower atmosphere (cloud level up to 100 kilometers).<ref>{{Cite web |title=ESA Science & Technology - PFS: The Planetary Fourier Spectrometer |url=https://sci.esa.int/web/venus-express/-/41529-pfs-the-planetary-fourier-spectrometer |access-date=2025-11-20 |website=sci.esa.int}}</ref>

Furthermore, it should have searched for minor atmospheric constituents that may be present, but had not yet been detected, analyzed atmospheric [[Particulate|aerosols]], and investigated surface to atmosphere exchange processes. The design was based on a [[spectrometer]] on ''Mars Express'', but modified for optimal performance for the ''Venus Express'' mission. However PFS failed during its deployment and no useful data was transmitted.<ref name="Lakdawalla2007">{{cite news |last1=Lakdawalla |first1=Emily |title=Venus Express PFS fails to respond to a swift kick |url=https://www.planetary.org/articles/1041 |access-date=2 February 2023 |work=The Planetary Society |date=July 23, 2007 |language=en}}</ref> 

'''SPICAV''': The "'''SP'''ectroscopy for '''I'''nvestigation of '''C'''haracteristics of the '''A'''tmosphere of '''V'''enus" (SPICAV) is an [[imaging spectrometer]] that was used for analyzing radiation in the infrared and ultraviolet wavelengths. It was derived from the ''SPICAM'' instrument flown on ''Mars Express''. However, SPICAV had an additional [[channel (digital image)|channel]] known as '''SOIR''' ('''S'''olar '''O'''ccultation at '''I'''nfra'''r'''ed) that was used to observe the Sun through Venus's atmosphere in the infrared.<ref>{{Cite journal |last=Bertaux |first=Jean-Loup |last2=Nevejans |first2=D. |last3=Korablev |first3=O. |last4=Villard |first4=E. |last5=Quémerais |first5=E. |last6=Neefs |first6=E. |last7=Montmessin |first7=F. |last8=Leblanc |first8=F. |last9=Dubois |first9=J. P. |last10=Dimarellis |first10=E. |last11=Hauchecorne |first11=A. |last12=Lefèvre |first12=F. |last13=Rannou |first13=P. |last14=Chaufray |first14=J. Y. |last15=Cabane |first15=M. |date=2007-10-01 |title=SPICAV on Venus Express: Three spectrometers to study the global structure and composition of the Venus atmosphere |url=https://www.sciencedirect.com/science/article/pii/S0032063307000074 |journal=Planetary and Space Science |series=The Planet Venus and the Venus Express Mission, Part 2 |volume=55 |issue=12 |pages=1673–1700 |doi=10.1016/j.pss.2007.01.016 |issn=0032-0633}}</ref><ref>{{Cite web |last=JUGLIN |first=MARION |title=Venus Express : SPICAV |url=https://www.ovsq.uvsq.fr/venus-express-spicav |access-date=2025-11-20 |website=Observatoire de Versailles Saint-Quentin-en-Yvelines - OVSQ |language=en}}</ref>

'''VIRTIS''': The "'''V'''isible and '''I'''nfra'''r'''ed '''T'''hermal '''I'''maging '''S'''pectrometer" (VIRTIS) was an [[imaging spectrometer]] that observed in the near-ultraviolet, visible, and [[infrared]] parts of the [[electromagnetic spectrum]]. It analyzed all layers of the atmosphere, surface temperature and surface/atmosphere interaction phenomena.<ref>{{Cite web |title=ESA Science & Technology - VIRTIS: The Visible and Infrared Thermal Imaging Spectrometer |url=https://sci.esa.int/web/venus-express/-/41537-virtis-the-visible-and-infrared-thermal-imaging-spectrometer |access-date=2025-11-20 |website=sci.esa.int}}</ref><ref>[https://lesia.obspm.fr/projets/virtis/Venus_Express/VIR-VEX_summary.pdf VIRTIS for Venus Express]</ref><ref>{{Cite web |title=VEX Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) |url=https://ode.rsl.wustl.edu/Venus/pagehelp/Content/Missions_Instruments/Venus%20Express/VIRTIS/Intro.htm |access-date=2025-11-20 |website=ode.rsl.wustl.edu}}</ref>

'''VeRa''': [[Radio science subsystem|'''Ve'''nus '''Ra'''dio Science]] was a radio sounding experiment that transmitted radio waves from the spacecraft and passed them through the atmosphere or reflected them off the surface. These radio waves were received by a ground station on Earth for analysis of the [[ionosphere]], atmosphere and surface of Venus. It was derived from the Radio Science Investigation instrument flown on ''[[Rosetta (spacecraft)|Rosetta]]''.<ref>{{Cite web |title=ESA Science & Technology - VeRa Bistatic Radio Experiment |url=https://sci.esa.int/web/venus-express/-/39700-vera-bistatic-radio-experiment |access-date=2025-11-20 |website=sci.esa.int}}</ref><ref>{{Cite journal |last=Häusler |first=B. |last2=Pätzold |first2=M. |last3=Tyler |first3=G. L. |last4=Simpson |first4=R. A. |last5=Bird |first5=M. K. |last6=Dehant |first6=V. |last7=Barriot |first7=J. -P. |last8=Eidel |first8=W. |last9=Mattei |first9=R. |last10=Remus |first10=S. |last11=Selle |first11=J. |last12=Tellmann |first12=S. |last13=Imamura |first13=T. |date=2006-11-01 |title=Radio science investigations by VeRa onboard the Venus Express spacecraft |url=https://www.sciencedirect.com/science/article/pii/S0032063306001590 |journal=Planetary and Space Science |series=The Planet Venus and the Venus Express Mission |volume=54 |issue=13 |pages=1315–1335 |doi=10.1016/j.pss.2006.04.032 |issn=0032-0633}}</ref>

==Mission history==

=== Background ===
The mission was proposed in 2001 to reuse the design of the ''[[Mars Express]]'' mission. However, some mission characteristics led to [[design]] changes: primarily in the areas of thermal control, communications and electrical power. For example, since [[Mars]] is approximately twice as far from the [[Sun]] as Venus, the radiant heating of the spacecraft was four times greater for ''Venus Express'' than ''[[Mars Express]]''. Also, the [[ionizing radiation]] environment was harsher. On the other hand, the more intense illumination of the [[Photovoltaic module|solar panels]] resulted in more generated [[solar cell|photovoltaic]] power. The ''Venus Express'' mission also used some spare instruments developed for the ''[[Rosetta space probe|Rosetta]]'' spacecraft. The mission was proposed by a consortium led by D. Titov (Germany), E. Lellouch (France), and F. Taylor (United Kingdom).<ref>{{Cite journal |last=Svedhem |first=H. |last2=Titov |first2=D. |last3=Taylor |first3=F. |last4=Witasse |first4=O. |date=2009 |title=Venus Express mission |url=https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2008JE003290 |journal=Journal of Geophysical Research: Planets |language=en |volume=114 |issue=E5 |doi=10.1029/2008JE003290 |issn=0148-0227}}</ref>

=== Launch campaign ===
''Venus Express'' completed its final phase of testing at [[EADS Astrium|Astrium]] Intespace<!-- Intespace sic! --> facility in [[Toulouse|Toulouse, France]] on 3 August 2005 and arrived at the airport of the [[Baikonur Cosmodrome]] on 7&nbsp;August 2005. First flight verification test was completed on 16 August 2005. Integrated System Test-3 was completed on 22 August 2005. Last major system test successfully started on 30 August 2005. Electrical testing was completed on 5&nbsp;September 2005. The Fuelling Readiness Review was completed on 21 September 2005. The spacecraft was mated to the [[Fregat|''Fregat'' upper stage]] on 12 October 2005.<ref>{{Cite web |title=ESA Science & Technology - Venus Express Mated with Fregat |url=https://sci.esa.int/web/venus-express/-/38116-12-october |access-date=2025-11-20 |website=sci.esa.int}}</ref>

The [[launch window]] for ''Venus Express'' was open from 26 October to 23 November 2005, with the launch initially set for 26 October 4:43 [[Coordinated Universal Time|UTC]]. However, problems with the insulation from the Fregat upper stage (detected on 21 October 2005) led to a two-week launch delay to inspect and clear out the small insulation debris that migrated on the spacecraft.<ref>{{cite web |date=25 October 2005 |title=Venus Express preliminary investigations bring encouraging news |url=http://www.esa.int/SPECIALS/Venus_Express/SEM2714J2FE_0.html |access-date=9 May 2006 |publisher=ESA}}</ref> The spacecarft arrived at launch pad on 5 November 2005 and it was launched by a [[Soyuz-FG]]/[[Fregat]] rocket on 9 November 2005 at 03:33:34 UTC into a parking Earth orbit and 1&nbsp;h 36&nbsp;min after launch put into its transfer orbit to Venus. <ref>{{Cite web |title=Venus Express {{!}} CNES |url=https://cnes.fr/en/projects/venus-express |archive-url=http://web.archive.org/web/20250720013219/https://cnes.fr/en/projects/venus-express |archive-date=2025-07-20 |access-date=2025-11-07 |website=cnes.fr |language=en}}</ref><ref>{{Cite web |title=Venus express : Launch successfull {{!}} Institut d'Astrophysique Spatiale |url=https://www.ias.u-psud.fr/en/content/venus-express-launch-successfull |access-date=2025-11-07 |website=www.ias.u-psud.fr}}</ref><ref>{{Cite journal |last=Svedhem |first=H. |last2=Titov |first2=D. V. |last3=McCoy |first3=D. |last4=Lebreton |first4=J. -P. |last5=Barabash |first5=S. |last6=Bertaux |first6=J. -L. |last7=Drossart |first7=P. |last8=Formisano |first8=V. |last9=Häusler |first9=B. |last10=Korablev |first10=O. |last11=Markiewicz |first11=W. J. |last12=Nevejans |first12=D. |last13=Pätzold |first13=M. |last14=Piccioni |first14=G. |last15=Zhang |first15=T. L. |date=2007-10-01 |title=Venus Express—The first European mission to Venus |url=https://www.sciencedirect.com/science/article/pii/S0032063307000050 |journal=Planetary and Space Science |series=The Planet Venus and the Venus Express Mission, Part 2 |volume=55 |issue=12 |pages=1636–1652 |doi=10.1016/j.pss.2007.01.013 |issn=0032-0633|url-access=subscription }}</ref>

=== In space ===
Three trajectory correction maneuvers were successfully performed on 11 November 2005, 24 February 2006, and 29 March 2006. The main engine was fired successfully on 17 February 2006 in a dress rehearsal for the arrival maneuver.<ref>{{cite web |date=17 February 2006 |title=Successful Venus Express main engine test |url=http://www.esa.int/SPECIALS/Venus_Express/SEMVX5MVGJE_0.html |access-date=9 May 2006 |publisher=European Space Agency}}</ref> The command stack for orbit insertion maneuver was loaded on the spacecraft on 7 April 2006. The spacecraft arrived at Venus on 11 April 2006, after 153 days of journey, and fired its main engine between 07:10:29 and 08:00:42 [[UTC]] [[Spacecraft Event Time|SCET]] to reduce its velocity so that it could be captured by Venusian [[gravity]] into an orbit of {{convert|400|by|330000|km|mi}}.<ref name="nssdc">{{cite web |title=Venus Express |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2005-045A |url-status=dead |archive-url=https://web.archive.org/web/20190415220347/https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2005-045A |archive-date=15 April 2019 |access-date=22 December 2014 |work=[[National Space Science Data Center]]}}</ref> The burn was monitored from ESA's Control Centre [[ESOC]] in [[Darmstadt, Germany]]. Period of this initial orbit was nine days.<ref name="nssdc" />
{| class="wikitable"
|+Venus Orbit Insertion (VOI) timeline<ref name="esa20070524">{{cite web |date=24 May 2007 |title=Venus orbit insertion |url=http://sci.esa.int/venus-express/38947-orbit-insertion/ |access-date=26 January 2015 |publisher=European Space Agency}}</ref>
|-
!Event
![[Spacecraft event time]] (UTC)
!Ground receive time (UTC)
|-
| Liquid Settling Phase start || 07:07:56 || 07:14:41
|-
| VOI main engine start || 07:10:29 || 07:17:14
|-
| periapsis passage || 07:36:35 ||
|-
| eclipse start || 07:37:46 ||
|-
| occultation start || 07:38:30 || 07:45:15
|-
| occultation end || 07:48:29 || 07:55:14
|-
| eclipse end || 07:55:11 ||
|-
| VOI burn end || 08:00:42 || 08:07:28
|}
Seven further orbit control maneuvers, two with the main engine and five with the thrusters, were required for ''Venus Express'' to reach its final operational 24-hour orbit around Venus.<ref name="nssdc" /> First images of Venus from ''Venus Express'' were released on 13 April 2006.<ref>{{Cite web |title=ESA Science & Technology - First Images from Venus Express |url=https://sci.esa.int/web/venus-express/-/39104-first-images-from-venus-express |access-date=2025-11-20 |website=sci.esa.int}}</ref>
{| class="wikitable"
|+Apoapsis Lowering Manoeuvres (ALM) timeline
!Time
!Event
!Result
|-
|20 April 2006
|[[Apoapsis]] Lowering Manoeuvre&nbsp;#1
|[[Orbital period]] changed to 40 hours
|-
|23 April 2006
|Apoapsis Lowering Manoeuvre&nbsp;#2
|Orbital period changed to 25 hours 43 minutes
|-
|26 April 2006
|Apoapsis Lowering Manoeuvre&nbsp;#3
|slight fix to previous ALM
|}

=== In target orbit ===
''Venus Express'' entered its target orbit at apoapsis on 7 May 2006 at 13:31 UTC, when the spacecraft was {{convert|151000000|km|mi}} from Earth. At this point the spacecraft was running on an [[ellipse]] substantially closer to the planet than during the initial orbit. The polar orbit ranged between {{convert|250|and|66000|km|mi}} over Venus. The [[periapsis]] was located almost above the North pole (80° North latitude), and it took 24 hours for the spacecraft to travel around the planet.<ref>{{Cite web |title=Venus Express has reached final orbit |url=https://www.esa.int/Science_Exploration/Space_Science/Venus_Express/Venus_Express_has_reached_final_orbit |access-date=2025-11-20 |website=www.esa.int |language=en}}</ref>

''Venus Express'' studied the [[Venusian atmosphere]] and clouds in detail, the [[Plasma (physics)|plasma]] environment and the surface characteristics of Venus from orbit. It also made global maps of the Venusian surface temperatures. Its nominal mission was originally planned to last for 500 Earth days (approximately two Venusian sidereal days) until 19 September 2007, but the mission was extended five times: first on 28 February 2007 until early May 2009; then on 4&nbsp;February 2009 until 31 December 2009; and then on 7 October 2009 until 31 December 2012.<ref>{{cite web |date=16 October 2009 |title=Mission extensions approved for science missions |url=http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=45685 |publisher=ESA}}</ref> On 22 November 2010, the mission was extended to 2014.<ref>{{cite web |date=22 November 2010 |title=Europe maintains its presence on the final frontier |url=http://sci.esa.int/director-desk/48007-europe-maintains-its-presence-on-the-final-frontier/ |publisher=ESA}}</ref> On 20 June 2013, the mission was extended a final time until 2015.<ref>{{cite web |date=20 June 2013 |title=ESA science missions continue in overtime |url=http://sci.esa.int/director-desk/51944-esa-science-missions-continue-in-overtime/ |publisher=ESA}}</ref> Between 18 June and 11 July 2014, the spacecraft performed successful [[aerobraking]] experiments<ref>{{cite web |last=Scuka |first=Daniel |date=16 May 2014 |title=Surfing an alien atmosphere |url=http://blogs.esa.int/rocketscience/2014/05/16/surfing-an-alien-atmosphere/ |access-date=23 November 2014 |publisher=European Space Agency}}</ref> with multiple passes at 131 to 135&nbsp;km altitude.<ref>{{cite web |date=11 July 2014 |title=Venus Express rises again |url=http://www.esa.int/Our_Activities/Space_Science/Venus_Express/Venus_Express_rises_again |access-date=14 April 2015 |publisher=European Space Agency}}</ref><ref>{{Cite web |title=Venus Express Will Gradually Sink Into History {{!}} Space |url=https://www.labroots.com/trending/space/269/venus-express-will-gradually-sink-into-history |access-date=2025-11-20 |website=Labroots}}</ref>

=== End of mission ===
On 28 November 2014, mission control lost contact with ''Venus Express''. Intermittent contact was reestablished on 3 December 2014, though there was no control over the spacecraft, likely due to exhaustion of propellant.<ref name="SpaceDaily-2014-12-08">{{cite news |date=8 December 2014 |title=Venus Express anomaly |url=http://www.spacedaily.com/reports/Venus_Express_anomaly_999.html |access-date=15 December 2014 |publisher=SpaceDaily}}</ref> On 16 December 2014, ESA announced that the ''Venus Express'' mission had ended.<ref name="esa20141216" /> A [[carrier signal]] was still being received from the vehicle, but no data was being transmitted. Mission manager Patrick Martin expected the spacecraft would fall below {{convert|150|km|mi}} in early January 2015, with destruction occurring in late January or early February.<ref name="natgeo20141217">{{cite news |last=Drake |first=Nadia |author-link=Nadia Drake |date=17 December 2014 |title=Out of Fuel, Venus Express Is Falling Gently to Its Death in Planet's Skies |url=http://news.nationalgeographic.com/news/2014/12/141217-venus-express-final-plunge-space-science/ |url-status=dead |archive-url=https://web.archive.org/web/20141218020323/http://news.nationalgeographic.com/news/2014/12/141217-venus-express-final-plunge-space-science/ |archive-date=18 December 2014 |access-date=22 December 2014 |work=National Geographic}}</ref> The spacecraft's carrier signal was last detected by ESA on 18 January 2015.<ref name="esa20150123" />

== Science results ==

* 14 December 2006: First temperature map of the southern hemisphere.<ref>{{Cite web |date=14 July 2009 |title=The new temperature map of Venus' southern hemisphere |url=http://www.esa.int/spaceinimages/Images/2009/07/The_new_temperature_map_of_Venus_southern_hemisphere |access-date=27 November 2016 |publisher=European Space Agency}}</ref>

* 27 November 2007: A series of papers was published in ''Nature'' giving the initial findings. It finds evidence for past oceans. It confirms the presence of lightning on Venus and that it is more common on Venus than it is on Earth. It also reports the discovery that a huge double [[Polar vortex|atmospheric vortex]] exists at the south pole of the planet.<ref>{{cite journal |last=Hand |first=Eric |date=27 November 2007 |title=European mission reports from Venus |url=http://www.nature.com/news/2007/071128/full/news.2007.297.html |journal=[[Nature (journal)|Nature]] |doi=10.1038/news.2007.297 |s2cid=129514118 |url-access=subscription |doi-access=free}}</ref><ref>{{cite news |date=28 November 2007 |title=Venus offers Earth climate clues |url=https://news.bbc.co.uk/2/hi/science/nature/7117303.stm |access-date=29 November 2007 |work=BBC News}}</ref>
* 20 May 2008: The detection by the VIRTIS instrument of [[hydroxyl]] (OH) in the atmosphere of Venus is reported in the May 2008 issue of [[Astronomy & Astrophysics]].<ref>{{cite web |date=20 May 2008 |title=Venus Express Provides First Detection of Hydroxyl in Atmosphere of Venus |url=http://www.spacedaily.com/reports/Venus_Express_Provides_First_Detection_Of_Hydroxyl_In_Atmosphere_Of_Venus_999.html |access-date=15 December 2014 |publisher=SpaceDaily}}</ref>
* October 2008: ''Venus Express'' was used to observe signs of life on [[Earth]] from Venus orbit. In images acquired by the probe, Earth was less than one pixel in size, which mimics observations of Earth-sized planets in other [[planetary system]]s. These observations were then used to develop methods for habitability studies of [[exoplanet]]s.<ref>{{cite web |title=Venus Express searching for life – on Earth |url=http://www.esa.int/esaCP/SEMUOW4N0MF_index_0.html |access-date=15 December 2014 |work=European Space Agency}}</ref>
* 25 August 2011: A layer of [[ozone]] was found in the upper atmosphere of Venus.<ref>{{cite news |last=Carpenter |first=Jennifer |date=7 October 2011 |title=Venus springs ozone layer surprise |url=https://www.bbc.co.uk/news/science-environment-15203281 |work=BBC News}}</ref><ref>{{cite journal |last1=Montmessin |first1=F. |last2=Bertaux |first2=J.-L. |last3=Lefèvre |first3=F. |last4=Marcq |first4=E. |last5=Belyaev |first5=D. |last6=Gérard |first6=J.-C. |last7=Korablev |first7=O. |last8=Fedorova |first8=A. |last9=Sarago |first9=V. |last10=Vandaele |first10=A. C. |display-authors=5 |date=November 2011 |title=A layer of ozone detected in the nightside upper atmosphere of Venus |url=https://orbi.uliege.be/handle/2268/100136 |journal=Icarus |volume=216 |issue=1 |pages=82–85 |bibcode=2011Icar..216...82M |doi=10.1016/j.icarus.2011.08.010 |hdl=2268/100136}}</ref>
* 1 October 2012: A cold layer, where [[dry ice]] may exists, was found in the atmosphere of Venus.<ref>{{cite web |date=1 October 2012 |title=A curious cold layer in the atmosphere of Venus |url=http://www.esa.int/Our_Activities/Space_Science/Venus_Express/A_curious_cold_layer_in_the_atmosphere_of_Venus |access-date=15 December 2014 |publisher=European Space Agency}}</ref>
* November 2025: Analysis of data from ''Venus Express'' and ''[[Akatsuki (spacecraft)|Akatsuki]]'' show that diurnal thermal tides are the primary driver of transporting momentum toward the tops of Venus's clouds, contributing substantially to the atmosphere's superrotation.<ref>{{Cite news |title=Key driver of extreme winds on Venus identified |url=https://phys.org/news/2025-11-key-driver-extreme-venus.html}}</ref><ref>{{Cite journal |last=Lai |first=Dexin |last2=Lebonnois |first2=Sebastien |last3=Li |first3=Tao |date=2025 |title=Contribution of Thermal Tides to Venus Upper Cloud‐Layer Superrotation |url=https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025AV001880 |journal=AGU Advances |language=en |volume=6 |issue=5 |doi=10.1029/2025AV001880 |issn=2576-604X}}</ref>

==See also==

{{Div col|colwidth=22em}}

* [[List of European Space Agency programmes and missions|List of ESA programmes and missions]]
* [[Uncrewed space mission]]
* [[List of planetary probes]]
* [[List of missions to Venus]]
* [[List of uncrewed spacecraft by program]]
* [[Space exploration]]
* [[Space telescope]]
* [[Space probe]]
* [[Timeline of artificial satellites and space probes]]
* [[Timeline of planetary exploration]]

{{Div col end}}

==References==

{{Reflist}}

==Further reading==

{{Commons category|Venus Express}}{{Portal|Spaceflight}}

* {{cite journal |url=http://www.mpg.de/798302/F002_Focus_026-033.pdf |title=The Blazing Hell Behind the Veil |journal=MaxPlanckResearch |first=Thorsten |last=Dambeck |issue=4 |year=2009 |pages=26–33 |id=B56133 |access-date=23 November 2014 |archive-date=3 March 2016 |archive-url=https://web.archive.org/web/20160303234527/http://www.mpg.de/798302/F002_Focus_026-033.pdf |url-status=dead }}

* {{cite journal |title=The Planet Venus and the Venus Express Mission |journal=Planetary and Space Science |first=Fredric W. |last=Taylor |volume=54 |issue=13–14 |pages=1247–1248 |date=November 2006 |bibcode=2006P&SS...54.1247T |doi=10.1016/j.pss.2006.06.013}}
* {{cite web |url=http://www.esa.int/About_Us/ESA_Permanent_Mission_in_Russia/Venus_Express_launch_campaign_starts |title=Venus Express launch campaign starts |publisher=European Space Agency |date=3 August 2005}}
* {{cite web |url=http://sci.esa.int/venus-express/31574-journal-archive/?farchive_objecttypeid=31&farchive_objectid=30928 |title=Venus Express Launch Campaign Journal |publisher=European Space Agency |access-date=16 August 2005}}
* {{cite web |url=http://sci.esa.int/venus-express/35192-3d-model/ |title=Interactive 3D model of the Venus Express spacecraft |publisher=European Space Agency |access-date=5 September 2005}}
* {{cite web |url=http://sci.esa.int/venus-express/33964-instruments/ |title=Venus Express: Instruments |publisher=European Space Agency |access-date=14 September 2005}}
* [http://www.esa.int/venus ''Venus Express'' mission page] by the European Space Agency
* [http://www.esa.int/Our_Activities/Operations/Venus_Express ''Venus Express'' mission page] by ESA Spacecraft Operations
* [https://web.archive.org/web/20070801222059/http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Venus_Express ''Venus Express'' profile] by NASA's Solar System Exploration

{{Venus spacecraft}}
{{European Space Agency}}
{{Satellite and spacecraft instruments}}
{{Solar System probes}}
{{Orbital launches in 2005}}

[[Category:Space probes launched in 2005]]
[[Category:European Space Agency space probes]]
[[Category:Embedded systems]]
[[Category:Missions to Venus]]
[[Category:Orbiters (space probe)]]
[[Category:Spacecraft launched by Soyuz-FG rockets]]
[[Category:2005 in spaceflight]]