Venus Express
Encyclopedia
Venus Express is the first Venus
exploration mission of the European Space Agency
. Launched in November 2005, it arrived at Venus in April 2006 and has been continuously sending back science data from its polar orbit around Venus. Equipped with seven science instruments, the main objective of the mission is the long term observation of the Venusian atmosphere. The observation over such long periods of time has never been done in previous missions to Venus, and is key to a better understanding of the atmospheric dynamics. It is hoped that such studies can contribute to an understanding of atmospheric dynamics in general, while also contributing to an understanding of climate change on Earth. The mission is currently funded by ESA through 31 December 2012.
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 is, the radiant heating of the spacecraft will be four times greater for Venus Express than Mars Express. Also, the ionizing radiation
environment will be harsher. On the other hand, the more intense illumination of the solar panels
will result in more generated photovoltaic
power. The Venus Express mission also uses some spare instruments developed for the Rosetta spacecraft. The mission was proposed by a consortium led by D. Titov (Germany), E. Lellouch (France) and F. Taylor (United Kingdom).
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 UTC
. However, problems with the insulation from the Fregat upper stage led to a two week launch delay to inspect and clear out the small insulation debris that migrated on the spacecraft. It was eventually launched by a Soyuz-FG
/Fregat
rocket from the Baikonur Cosmodrome
in Kazakhstan
on 9 November 2005 at 03:33:34 UTC into a parking Earth orbit and 1 h min after launch put into its transfer orbit to Venus. A first trajectory correction maneuver was successfully performed on 11 November 2005. It arrived at Venus on 11 April 2006, after 153 days of journey, and fired its main engine between 07:10 and 08:00 Universal Time (UTC) to reduce its velocity so that it could be captured by Venusian gravity into a nine day orbit. The burn was monitored from ESA's Control Centre, ESOC, in Darmstadt, Germany.
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.
Venus Express entered its target orbit at apocentre on 7 May 2006 at 13:31 UTC, when the spacecraft was at 151 million kilometres from Earth. Now the spacecraft is running on an ellipse
substantially closer to the planet than during the initial orbit. The orbit now ranges between 66,000 and 250 kilometres over Venus and it is polar. The pericentre
is located almost above the North pole (80° North latitude), and it takes 24 hours for the spacecraft to travel around the planet.
Venus Express is studying the Venusian atmosphere
and clouds in detail, the plasma
environment and the surface characteristics of Venus from orbit. It will also make global maps of the Venusian surface temperatures. Its nominal mission was originally planned to last for 500 Earth days (approximately two Venusian sidereal days), but the mission has been extended three times: first on 28 February 2007 until early May 2009; then on 4 February 2009 until 31 December 2009; and then on 7 October 2009 until 31 December 2012. On-board resources are sized for an additional 500 Earth days.
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.
VMC: The Venus Monitoring Camera is a wide-angle, multi-channel CCD
. The VMC is designed for global imaging of the planet. It operates in the visible, ultraviolet, and near infrared 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. It is derived in part by the Mars Express High Resolution Stereo Camera (HRSC)
and the Rosetta Optical, Spectroscopic and Infrared Remote Imaging System (OSIRIS)
. The camera includes an FPGA to pre-process image data, reducing the amount transmitted to Earth. The consortium of institutions responsible for the VMC includes 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
.
is 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 will be able to map the magnetosheath
, 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 is derived from the Rosetta lander's ROMAP instrument.
between the 0.9 µm
and 45 µm wavelength range and is designed to perform vertical optical sounding of the Venus atmosphere. It will perform global, long-term monitoring of the three-dimensional temperature field in the lower atmosphere (cloud level up to 100 kilometers). Furthermore it will search for minor atmospheric constituents that may be present, but have not yet been detected, analyze atmospheric aerosols, and investigate surface to atmosphere exchange processes. The design is based on a spectrometer on Mars Express, but modified for optimal performance for the Venus Express mission.
SPICAV: The "SPectroscopy for Investigation of Characteristics of the Atmosphere of Venus" (SPICAV) is an imaging spectrometer that will be used for analyzing radiation in the infrared and ultraviolet wavelengths. It is derived from the SPICAM instrument flown on Mars Express. However, SPICAV has an additional channel
known as SOIR (Solar Occultation at Infrared) that will be used to observe the Sun through Venus's atmosphere in the infrared.
VIRTIS: The "Visible and Infrared Thermal Imaging Spectrometer" (VIRTIS) is an imaging spectrometer that observes in the near-ultraviolet, visible, and infrared
parts of the electromagnetic spectrum
. It will analyze all layers of the atmosphere, surface temperature and surface/atmosphere interaction phenomena.
is a radio sounding experiment that will transmit radio waves from the spacecraft and pass them through the atmosphere or reflect them off the surface. These radio waves will be received by a ground station on Earth for analysis of the ionosphere
, atmosphere and surface of Venus. It is derived from the Radio Science Investigation instrument flown on Rosetta.
from Venus orbit. In the pictures, Earth is less than one pixel in size, which mimics observations of Earth-sized planets in other solar systems. These observations are then used to develop methods for habitability studies of extra-solar planets.
|-
!
!spacecraft 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
|-
| pericentre 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
|}
Venus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...
exploration mission of the European Space Agency
European Space Agency
The European Space Agency , established in 1975, is an intergovernmental organisation dedicated to the exploration of space, currently with 18 member states...
. Launched in November 2005, it arrived at Venus in April 2006 and has been continuously sending back science data from its polar orbit around Venus. Equipped with seven science instruments, the main objective of the mission is the long term observation of the Venusian atmosphere. The observation over such long periods of time has never been done in previous missions to Venus, and is key to a better understanding of the atmospheric dynamics. It is hoped that such studies can contribute to an understanding of atmospheric dynamics in general, while also contributing to an understanding of climate change on Earth. The mission is currently funded by ESA through 31 December 2012.
History
The mission was proposed in 2001 to reuse the design of the Mars ExpressMars Express
Mars Express is a space exploration mission being conducted by the European Space Agency . The Mars Express mission is exploring the planet Mars, and is the first planetary mission attempted by the agency. "Express" originally referred to the speed and efficiency with which the spacecraft was...
mission. However, some mission characteristics led to design
Design
Design as a noun informally refers to a plan or convention for the construction of an object or a system while “to design” refers to making this plan...
changes: primarily in the areas of thermal control, communications and electrical power. For example, since Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
is approximately twice as far from the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
as Venus is, the radiant heating of the spacecraft will be four times greater for Venus Express than Mars Express. Also, the ionizing radiation
Ionizing radiation
Ionizing radiation is radiation composed of particles that individually have sufficient energy to remove an electron from an atom or molecule. This ionization produces free radicals, which are atoms or molecules containing unpaired electrons...
environment will be harsher. On the other hand, the more intense illumination of the solar panels
Photovoltaic module
A solar panel is a packaged, connected assembly of solar cells, also known as photovoltaic cells...
will result in more generated photovoltaic
Solar cell
A solar cell is a solid state electrical device that converts the energy of light directly into electricity by the photovoltaic effect....
power. The Venus Express mission also uses some spare instruments developed for the Rosetta spacecraft. The mission was proposed by a consortium led by D. Titov (Germany), E. Lellouch (France) and F. Taylor (United Kingdom).
The launch window
Launch window
Launch window is a term used in spaceflight to describe a time period in which a particular launch vehicle must be launched. If the rocket does not launch within the "window", it has to wait for the next window....
for Venus Express was open from 26 October to 23 November 2005, with the launch initially set for 26 October 4:43 UTC
Coordinated Universal Time
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...
. However, problems with the insulation from the Fregat upper stage led to a two week launch delay to inspect and clear out the small insulation debris that migrated on the spacecraft. It was eventually launched by a Soyuz-FG
Soyuz-FG
The Soyuz-FG launch vehicle is an improved version of the Soyuz-U, from the R-7 family of rockets, designed and constructed by TsSKB-Progress in Samara...
/Fregat
Fregat
Fregat is a type of rocket stage developed by NPO Lavochkin in the 1990s. Its main engine is a liquid propellant rocket that uses UDMH and N2O4 as propellants.- Specifications :...
rocket from the Baikonur Cosmodrome
Baikonur Cosmodrome
The Baikonur Cosmodrome , also called Tyuratam, is the world's first and largest operational space launch facility. It is located in the desert steppe of Kazakhstan, about east of the Aral Sea, north of the Syr Darya river, near Tyuratam railway station, at 90 meters above sea level...
in Kazakhstan
Kazakhstan
Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...
on 9 November 2005 at 03:33:34 UTC into a parking Earth orbit and 1 h min after launch put into its transfer orbit to Venus. A first trajectory correction maneuver was successfully performed on 11 November 2005. It arrived at Venus on 11 April 2006, after 153 days of journey, and fired its main engine between 07:10 and 08:00 Universal Time (UTC) to reduce its velocity so that it could be captured by Venusian gravity into a nine day orbit. The burn was monitored from ESA's Control Centre, ESOC, in Darmstadt, Germany.
Seven further orbit control maneuvers, two with the main engine and five with the thrusters
Rocket engine
A rocket engine, or simply "rocket", is a jet engineRocket Propulsion Elements; 7th edition- chapter 1 that uses only propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines and obtain thrust in accordance with Newton's third law...
, were required for Venus Express to reach its final operational 24-hour orbit around Venus.
Venus Express entered its target orbit at apocentre on 7 May 2006 at 13:31 UTC, when the spacecraft was at 151 million kilometres from Earth. Now the spacecraft is running on an ellipse
Ellipse
In geometry, an ellipse is a plane curve that results from the intersection of a cone by a plane in a way that produces a closed curve. Circles are special cases of ellipses, obtained when the cutting plane is orthogonal to the cone's axis...
substantially closer to the planet than during the initial orbit. The orbit now ranges between 66,000 and 250 kilometres over Venus and it is polar. The pericentre
Apsis
An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
is located almost above the North pole (80° North latitude), and it takes 24 hours for the spacecraft to travel around the planet.
Venus Express is studying the Venusian atmosphere
Atmosphere of Venus
The atmosphere of Venus is much denser and hotter than that of Earth. The temperature at the surface is 740 K , while the pressure is 93 bar. The Venusian atmosphere supports opaque clouds made of sulfuric acid, making optical Earth-based and orbital observation of the surface impossible...
and clouds in detail, the plasma
Plasma (physics)
In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
environment and the surface characteristics of Venus from orbit. It will also make global maps of the Venusian surface temperatures. Its nominal mission was originally planned to last for 500 Earth days (approximately two Venusian sidereal days), but the mission has been extended three times: first on 28 February 2007 until early May 2009; then on 4 February 2009 until 31 December 2009; and then on 7 October 2009 until 31 December 2012. On-board resources are sized for an additional 500 Earth days.
Instruments
ASPERA-4: An acronym for "Analyzer of Space Plasmas and Energetic Atoms," ASPERA-4 will investigate the interaction between the solar windSolar wind
The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...
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.
VMC: The Venus Monitoring Camera is a wide-angle, multi-channel CCD
Charge-coupled device
A charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...
. The VMC is designed for global imaging of the planet. It operates in the visible, ultraviolet, and near infrared spectral ranges, and maps surface brightness distribution searching for volcanic activity, monitoring airglow
Airglow
Airglow is the very weak emission of light by a planetary atmosphere. In the case of Earth's atmosphere, this optical phenomenon causes the night sky to never be completely dark .-Development:The airglow phenomenon was first identified in 1868 by Swedish scientist...
, studying the distribution of unknown ultraviolet absorbing phenomenon at the cloud-tops, and making other science observations. It is derived in part by the Mars Express High Resolution Stereo Camera (HRSC)
HiRISE
High Resolution Imaging Science Experiment is a camera on board the Mars Reconnaissance Orbiter. The 65 kg , $40 million instrument was built under the direction of the University of Arizona's Lunar and Planetary Laboratory by Ball Aerospace & Technologies Corp....
and the Rosetta Optical, Spectroscopic and Infrared Remote Imaging System (OSIRIS)
OSIRIS
OSIRIS is the name of three entirely separate astronomical instruments. The duplication of names is coincidental, partly driven by two scientific teams trying to make acronyms using similar words.-OH-Suppressing Infrared Integral Field Spectrograph:...
. The camera includes an FPGA to pre-process image data, reducing the amount transmitted to Earth. The consortium of institutions responsible for the VMC includes the Max Planck Institute for Solar System Research
Max Planck Institute for Solar System Research
The Max Planck Institute for Solar System Research is a research institute in Astronomy/Astrophysics, located in Lindau , Germany; 20 km north east of Göttingen. The exploration of our solar system is the central theme for the scientific research done at this Institute...
, the Institute of Planetary Research at the German Aerospace Center
German Aerospace Center
The German Aerospace Center is the national centre for aerospace, energy and transportation research of the Federal Republic of Germany. It has multiple locations throughout Germany. Its headquarters are located in Cologne. It is engaged in a wide range of research and development projects in...
and the Institute of Computer and Communication Network Engineering at Technische Universität Braunschweig
Technische Universität Braunschweig
The TU Braunschweig is the oldest University of Technology in Germany. It was founded in 1745 as Collegium Carolinum and is a member of TU9, an incorporated society of the most renowned and largest German Institutes of Technology. Today it has about 13,000 students, making it the third largest...
.
Magnetometer
MAG: The magnetometerMagnetometer
A magnetometer is a measuring instrument used to measure the strength or direction of a magnetic field either produced in the laboratory or existing in nature...
is 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 will be able to map the magnetosheath
Magnetosheath
The magnetosheath is the region of space between the magnetopause and the bow shock of a planet's magnetosphere. The regularly organized magnetic field generated by the planet becomes weak and irregular in the magnetosheath due to interaction with the incoming solar wind, and is incapable of fully...
, magnetotail
Magnetosphere
A magnetosphere is formed when a stream of charged particles, such as the solar wind, interacts with and is deflected by the intrinsic magnetic field of a planet or similar body. Earth is surrounded by a magnetosphere, as are the other planets with intrinsic magnetic fields: Mercury, Jupiter,...
, ionosphere
Ionosphere
The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...
, 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 is derived from the Rosetta lander's ROMAP instrument.
Spectrometer
PFS: The "Planetary Fourier Spectrometer" (PFS) operates in the infraredInfrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
between the 0.9 µm
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
and 45 µm wavelength range and is designed to perform vertical optical sounding of the Venus atmosphere. It will perform global, long-term monitoring of the three-dimensional temperature field in the lower atmosphere (cloud level up to 100 kilometers). Furthermore it will search for minor atmospheric constituents that may be present, but have not yet been detected, analyze atmospheric aerosols, and investigate surface to atmosphere exchange processes. The design is based on a spectrometer on Mars Express, but modified for optimal performance for the Venus Express mission.
SPICAV: The "SPectroscopy for Investigation of Characteristics of the Atmosphere of Venus" (SPICAV) is an imaging spectrometer that will be used for analyzing radiation in the infrared and ultraviolet wavelengths. It is derived from the SPICAM instrument flown on Mars Express. However, SPICAV has an additional channel
Channel (digital image)
Color digital images are made of pixels, and pixels are made of combinations of primary colors. A channel in this context is the grayscale image of the same size as a color image, made of just one of these primary colors. For instance, an image from a standard digital camera will have a red, green...
known as SOIR (Solar Occultation at Infrared) that will be used to observe the Sun through Venus's atmosphere in the infrared.
VIRTIS: The "Visible and Infrared Thermal Imaging Spectrometer" (VIRTIS) is an imaging spectrometer that observes in the near-ultraviolet, visible, and infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
parts of the electromagnetic spectrum
Electromagnetic spectrum
The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object....
. It will analyze all layers of the atmosphere, surface temperature and surface/atmosphere interaction phenomena.
Radio science
VeRa: Venus Radio ScienceRadio Science Subsystem
The Radio Science Subsystem on a scientific spacecraft uses radio signals to probe a medium such as a planetary atmosphere. The spacecraft transmits a highly stable signal to ground stations, receives such a signal from ground stations, or both...
is a radio sounding experiment that will transmit radio waves from the spacecraft and pass them through the atmosphere or reflect them off the surface. These radio waves will be received by a ground station on Earth for analysis of the ionosphere
Ionosphere
The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...
, atmosphere and surface of Venus. It is derived from the Radio Science Investigation instrument flown on Rosetta.
Climate of Venus
Starting out in the early planetary system with similar sizes and chemical compositions, the histories of the two planets have diverged in spectacular fashion. It is hoped that the Venus Express mission can contribute not only to an in-depth understanding of how the Venusian atmosphere is structured, but also to an understanding of the changes that led to the current greenhouse atmospheric conditions. Such an understanding may contribute to the study of climate change in on Earth.Search for life on Earth
Venus Express is used also to observe signs of life on EarthEarth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
from Venus orbit. In the pictures, Earth is less than one pixel in size, which mimics observations of Earth-sized planets in other solar systems. These observations are then used to develop methods for habitability studies of extra-solar planets.
Important events and discoveries
- 3 August 2005: Venus Express completed its final phase of testing at AstriumEADS AstriumAstrium Satellites is one of the three business units of Astrium, a subsidiary of EADS. It is a European space manufacturer involved in the manufacture of spacecraft used for science, Earth observation and telecommunication, as well as the equipment and subsystems used therein and related ground...
Intespace facility in Toulouse, FranceToulouseToulouse is a city in the Haute-Garonne department in southwestern FranceIt lies on the banks of the River Garonne, 590 km away from Paris and half-way between the Atlantic Ocean and the Mediterranean Sea...
. It flew on a Antonov An-124Antonov An-124The Antonov An-124 Ruslan is a strategic airlift jet aircraft. It was designed by the Ukrainian SSR's Antonov design bureau, then part of the Soviet Union. It is the world's largest ever serially-manufactured cargo airplane and world's second largest operating cargo aircraft...
cargo aircraft via Moscow, before arriving at Baikonur on 7 August. - 7 August 2005: Venus Express arrived at the airport of the Baikonur CosmodromeBaikonur CosmodromeThe Baikonur Cosmodrome , also called Tyuratam, is the world's first and largest operational space launch facility. It is located in the desert steppe of Kazakhstan, about east of the Aral Sea, north of the Syr Darya river, near Tyuratam railway station, at 90 meters above sea level...
. - 16 August 2005: First flight verification test completed.
- 22 August 2005: Integrated System Test-3.
- 30 August 2005: Last Major System Test Successfully Started.
- 5 September 2005: Electrical Testing Successful.
- 21 September 2005: FRR (Fuelling Readiness Review) Ongoing.
- 12 October 2005: Mating to the Fregat upper stage completed.
- 21 October 2005: Contamination detected inside the fairingPayload fairingPayload fairing is one of the main components of a launch vehicle. The fairing protects the payload during the ascent against the impact of the atmosphere . More recently, an additional function is to maintain the cleanroom environment for precision instruments.Outside the atmosphere the fairing is...
— launch on hold. - 5 November 2005: Arrival at launch pad.
- 9 November 2005: Launch from Baikonur Cosmodrome at 03:33:34 UTC.
- 11 November 2005: First trajectory correction maneuver successfully performed.
- 17 February 2006: The main engine is fired successfully in a dress rehearsal for the arrival maneuver.
- 24 February 2006: Second trajectory correction maneuver successfully performed.
- 29 March 2006: Third trajectory correction maneuver successfully performed - on target for 11 April orbit insertion.
- 7 April 2006: Command stack for orbit insertion maneuver is loaded on the spacecraft.
- 11 April 2006: The Venus Orbit Insertion (VOI) is completed successfully, according to the following timeline:
-
- {| class="wikitable"
|-
!
!spacecraft 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
|-
| pericentre 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
|}
-
-
- Period of this orbit is nine days.
- 13 April 2006: First images of Venus from Venus Express released.
- 20 April 2006: Apocentre Lowering Manoeuvre #1 performed. Orbital period is now 40 hours.
- 23 April 2006: Apocentre Lowering Manoeuvre #2 performed. Orbital period is now approx 25 hours 43 minutes.
- 26 April 2006: Apocentre Lowering Manoeuvre #3 is slight fix to previous ALM.
- 7 May 2006: Venus Express entered its target orbit at apocentre at 13:31 UTC
- 14 December 2006: First temperature map of the southern hemisphere.
- 27 February 2007: ESA agrees to fund mission extension until May 2009.
- 19 September 2007: End of the nominal mission (500 Earth days) - Start of mission extension.
- 27 November 2007: The scientific journal Nature publishes a series of papers 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 atmospheric vortexPolar vortexA polar vortex is a persistent, large-scale cyclone located near one or both of a planet's geographical poles. On Earth, the polar vortices are located in the middle and upper troposphere and the stratosphere...
exists at the south pole of the planet. - 20 May 2008: The detection by the VIRTIS instrument on Venus Express of hydroxylHydroxylA hydroxyl is a chemical group containing an oxygen atom covalently bonded with a hydrogen atom. In inorganic chemistry, the hydroxyl group is known as the hydroxide ion, and scientists and reference works generally use these different terms though they refer to the same chemical structure in...
(OH) in the atmosphere of Venus is reported in the May 2008 issue of Astronomy and AstrophysicsAstronomy and Astrophysics* Astronomy and Astrophysics has a 2010 impact factor of 4.410.-See also:*The Astronomy and Astrophysics Review*Advanced Satellite for Cosmology and Astrophysics*Astronomy & Geophysics*Astronomical Journal*Astrophysical Journal...
. - 4 February 2009: ESA agrees to fund mission extension until 31 December 2009.
- 7 October 2009: ESA agrees to fund the mission through 31 December 2012.
- Period of this orbit is nine days.
-
See also
- Unmanned space mission
- Geosynchronous satelliteGeosynchronous satelliteA geosynchronous Satellite is a satellite whose orbit on the Earth repeats regularly over points on the Earth over time. If such a satellite's orbit lies over the equator, the orbit is circular and its angular velocity is the same as the earth's, then it is called a geostationary satellite...
- List of planetary probes
- List of unmanned spacecraft by program
- Space explorationSpace explorationSpace exploration is the use of space technology to explore outer space. Physical exploration of space is conducted both by human spaceflights and by robotic spacecraft....
- Space observatorySpace observatoryA space observatory is any instrument in outer space which is used for observation of distant planets, galaxies, and other outer space objects...
- Space probeSpace probeA robotic spacecraft is a spacecraft with no humans on board, that is usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe. Many space missions are more suited to telerobotic rather than crewed operation, due to...
- Timeline of artificial satellites and space probesTimeline of artificial satellites and space probesThis timeline of artificial satellites and space probes includes unmanned spacecraft including technology demonstrators, observatories, lunar probes, and interplanetary probes. First satellites from each country are included. Not included are most earth science satellites, commercial satellites or...
- Timeline of planetary exploration
Further reading
Thorsten Dambeck: The Blazing Hell Behind the Veil , MaxPlanckResearch, 4/2009, p. 26 - 33External links
- ESA description of the Venus Express mission
- ESA Science & Technology - Venus Express page
- ESA Spacecraft Operations - Venus Express page
- Venus Express Program Page by NASA's Solar System Exploration
- Venus Express: The first European mission to Venus
- Extrasolar-planets.com — Venus Express
- Orbit Insertion - Scheduled events to shape orbit concluding 6 May 2006
- Map of temperatures of South Hemisphere of Venus planet
- apr 2007-esa-1.html 04/03/07: Venus Express: Tracking Violent Winds and Turbulences Site includes full coverage of the Venus Express Mission
- Amateurs Assist Venus Express Mission
- Japan Aerospace Exploration Agency
- Planet-C mission to Venus