duminică, 27 ianuarie 2013
miercuri, 23 ianuarie 2013
PRESS BRIEFING ON ESA SERVICE MODULE FOR NASA'S ORION SPACECRAFT
Loading...
ESA - HELIX NEBULA - THE SCIENCE CLOUD' PUBLIC EVENT
HELIX NEBULA - THE SCIENCE CLOUD' PUBLIC EVENT PART 1
Loading...
Loading...
duminică, 20 ianuarie 2013
vineri, 11 ianuarie 2013
luni, 7 ianuarie 2013
vineri, 4 ianuarie 2013
ESA other projects
BEPICOLOMBO - Mercury
Status: Being built and tested
Objective:
One of ESA’s cornerstone missions, it will study and understand the composition, geophysics, atmosphere, magnetosphere and history of Mercury, the least explored planet in the inner Solar System.
One of ESA’s cornerstone missions, it will study and understand the composition, geophysics, atmosphere, magnetosphere and history of Mercury, the least explored planet in the inner Solar System.
Mission:
BepiColombo will provide the best understanding of Mercury to date. It consists of two individual orbiters: the Mercury Planetary Orbiter (MPO) to map the planet, and the Mercury Magnetospheric Orbiter (MMO) to investigate its magnetosphere.
BepiColombo will provide the best understanding of Mercury to date. It consists of two individual orbiters: the Mercury Planetary Orbiter (MPO) to map the planet, and the Mercury Magnetospheric Orbiter (MMO) to investigate its magnetosphere.
What’s special?
Most of ESA's previous interplanetary missions have been to relatively cold parts of the Solar System. BepiColombo will be the Agency's first experience of sending a planetary probe close to the Sun.
BepiColombo’s mission is especially challenging because Mercury's orbit is so close to our star. The planet is hard to observe from a distance, because the Sun is so bright. Furthermore, it is difficult to reach because a spacecraft must lose a lot of energy to ‘fall’ towards the planet from the Earth. The Sun’s enormous gravity presents a challenge in placing a spacecraft into a stable orbit around Mercury.
Only NASA's Mariner 10 and Messenger have visited Mercury so far. Mariner 10 provided the first-ever close-up images of the planet when it flew past three times in 1974-1975. En route to its final destination in orbit around Mercury in 18 March 2011, Messenger flew past the planet 3 times (14 January 2008, 6 October 2008, and 29 September 2009), providing new data and images. Once BepiColombo arrives in 2022, it will help reveal information on the composition and history of Mercury. It should discover more about the formation and the history of the inner planets in general, including Earth.
Spacecraft
The BepiColombo mission is based on two spacecraft:
- a Mercury Planetary Orbiter (MPO); and
- a Mercury Magnetospheric Orbiter (MMO)
Among several investigations, BepiColombo will make a complete map of Mercury at different wavelengths. It will chart the planet's mineralogy and elemental composition, determine whether the interior of the planet is molten or not, and investigate the extent and origin of Mercury’s magnetic field.
Journey
Several launch methods have been extensively studied. In the selected scenario, BepiColombo will use the gravity of the Earth, Venus and Mercury in combination with the thrust provided by solar-electric propulsion (SEP). During the voyage to Mercury, the two orbiters and a transfer module, consisting of electric propulsion and traditional chemical rocket units, will form one single composite spacecraft.
When approaching Mercury in 2022, the transfer module will be separated and the composite spacecraft will use rocket engines and a technique called 'weak stability boundary capture’ to bring it into polar orbit around the planet. When the MMO orbit is reached, the MPO will separate and lower its altitude to its own operational orbit. Observations from orbit will be taken for at least one Earth year with the possibility of an extension.
History
As the nearest planet to the Sun, Mercury has an important role in showing us how planets form. Mercury, Venus, Earth and Mars make up the family of terrestrial planets; each one carrying essential information to trace the history of the whole group.
The knowledge of how they originated and evolved is key to understanding how conditions supporting life arose in the Solar System, and possibly elsewhere. As long as Earth-like planets orbiting other stars remain inaccessible to astronomers, the Solar System is the only laboratory where scientists can test models applicable to other planetary systems.
Exploring Mercury is therefore fundamental to answering important astrophysical and philosophical questions such as 'Are Earth-like planets common in the Galaxy?'
A European mission to Mercury was first proposed in May 1993. Although an assessment showed it to be too costly for a medium-size mission, ESA made a Mercury orbiter one of its three new cornerstone missions when the Horizon 2000 science programme was extended in 1994. Gaia competed with BepiColombo for the fifth cornerstone mission. In October 2000, ESA approved a package of missions for 2008–2013 and both BepiColombo and Gaia were approved.
In February 2007, the mission was approved as part of the Cosmic Vision programme. Following an unavoidable increase in the mission’s mass during 2008, the launch vehicle was changed from Soyuz-Fregat to Ariane 5. Final approval for the redesigned mission was given by ESA’s Science Programme Committee in November 2009.
BepiColombo represents the first time ESA and JAXA have joined forces for the implementation of a major space science mission.
Partnerships
BepiColombo is a joint mission between ESA and the Japanese Aerospace Exploration Agency (JAXA), executed under ESA leadership.
CLUSTER :
Cluster is a constellation of four spacecraft flying in formation around Earth. They relay the most detailed information ever about how the solar wind affects our planet in three dimensions. The solar wind (the perpetual stream of subatomic particles given out by the Sun) can damage communications satellites and power stations on Earth. The original operation life-time of the Cluster mission ran from February 2001 to December 2005. However, in February 2005, ESA approved a mission extension from December 2005 to December 2009.
The four Cluster spacecraft have spent several years passing in and out of our planet's magnetic field. Their mission will be to complete the most detailed investigation ever made into the ways in which the Sun and Earth interact.
What's special?
The Sun emits the solar wind, which is a thin, hot, ionised gas that carries particles and magnetic fields outward from the Sun.
The Earth is shielded from the full blast by its magnetosphere, the region around our planet controlled by its magnetic field. Some solar wind descends into Earth's upper atmosphere through the polar cusps, funnel-like openings in the magnetosphere at the poles. These energetic particles excite atoms and molecules in the upper atmosphere to create the Northern and Southern Lights (the auroras). The part of a planetary magnetosphere that is pushed in the direction of the solar wind is known as the magnetotail.
Cluster will determine the physical processes involved in the interaction between the solar wind and the magnetosphere by visiting key regions like the polar cusps and the magnetotail. The four Cluster spacecraft map the plasma structures contained in these regions in three dimensions. The simultaneous four-point measurements also allow close studies of plasma quantities in both space and time.
During periods of high solar activity (which cycles every 11 years), the solar wind can be particularly energetic. This can have a dramatic effect on human activities, disrupting electrical power and telecommunications or causing serious problems in the operation of satellites, especially those in geostationary orbit. Subtle changes to the weather on Earth also occur during these times. Watching the effects of this increased activity during these periods is one of the main tasks of Cluster.
Understanding the interaction between the solar wind and the magnetosphere and how the plasma levels of the magnetosphere are affected is important. Cluster will help us to prepare for the effects of sudden bursts of solar energy here on Earth.
Spacecraft
The Cluster spacecraft resemble giant 'Lego' sets, assembled from thousands of individual blocks. Each one is shaped like a giant disc, 1.3 metres high and 2.9 metres wide, with a cylinder in the centre.
Six spherical fuel tanks are attached to the outside of this central cylinder. The fuel they carry accounts for more than half the launch weight of each spacecraft. Most of the fuel is consumed soon after launch and in complex manoeuvres to reach their operational orbits. Each spacecraft also carries eight thrusters for smaller changes of orbit.
Around the central cylinder is the main equipment platform. Electrical power comes from six curved solar panels attached around the outside of the platform. Five batteries are used for power supply during the four-hour-long eclipses when the spacecraft enter Earth's shadow.
Rod-shaped booms open out once Cluster reaches orbit. There are two antennae for communications, two sensors, and four wire booms that operate when the spacecraft begins to spin. These measure changing electrical and magnetic fields around each spacecraft.
Journey
At each launch, two Cluster satellites were placed in an elliptical orbit whose height varied from 200 to 18 000 kilometres above Earth. The two satellites of each launch were then released, one after the other and used their own on-board propulsion systems to reach the final operational orbit (19 000 to 119 000 kilometres from the planet).
The first pair of Cluster satellites lifted off on 16 July 2000, the second pair one month later. This gap allowed fewer people to be used for mission control in the European Space Operations Centre (ESOC) in Darmstadt (Germany).
Once the booster reached the correct altitude, after liftoff, the Fregat payload assist module and its two Cluster spacecraft were released. The Fregat main engine fired almost immediately to achieve a circular orbit of approximately 200 kilometres high. About an hour later, the Fregat engine fired again to inject the spacecraft into an elliptical orbit.
The two satellites were released, one after the other. Each Cluster spacecraft main engine performed six major manoeuvres, using the large amount of on-board fuel (about half of each satellite's launch mass).
History
The Cluster mission was first proposed in November 1982. The idea was developed into a proposal to study the 'cusp' and the ‘magnetotail’ regions of the Earth's magnetosphere with a polar orbiting mission. The Cluster idea developed into a proposal and then a mission. In 1996, Cluster was ready for launch.
Cluster was expected to benefit from a 'free' launch on the first test flight of the newly developed Ariane-5 booster. After several minor delays, Ariane-501 lifted off from Kourou, French Guiana on 4 June 1996, carrying its payload of four Cluster satellites. Unfortunately, intense aerodynamic loads resulted in its break-up and initiation of the automatic destruct system.
To recover some of the unique science from the mission, ESA decided to build a fifth Cluster satellite (named `Phoenix'). It would be equipped with flight spares of the experiments and subsystems prepared for the Cluster mission. Phoenix was expected to be fully integrated and tested by mid-1997, opening the way for a launch later that year. However, awareness grew that the scientific objectives of the Cluster mission could not be met by a single spacecraft. There were proposals to rebuild three or four full-size Cluster spacecraft alongside Phoenix.
After a preliminary study, it was decided that a Soyuz rocket could launch a pair of Cluster spacecraft. However, the very eccentric orbit required a new upper stage. Two flights were successfully done at the beginning of 2000 and about six months later, Cluster was launched by a Soyuz-Fregat launcher from Baikonur Cosmodrome, Kazakhstan.
On 10 February 2005, the ESA Science Programme Committee approved unanimously the extension of the Cluster mission, pushing back the end date from December 2005 to December 2009. This extension will allow the first measurements of space plasmas at both small and large scales simultaneously and the sampling of geospace regions never crossed before by four spacecraft flying in close formation.
In October 2009 the mission was extended until end 2012.
Partnerships
Prime contractor for the original (lost) Cluster and replacement Cluster satellites was Dornier Satellitensysteme GmbH (now Astrium), Friedrichshafen, Germany, the leader of an industrial consortium involving 35 major contractors from all of the ESA member countries and the United States.
Each spacecraft carries an identical set of 11 instruments to investigate charged particles, electrical, and magnetic fields. These were built by European and American instrument teams led by Principal Investigators.
The Cluster scientific community includes the ESA Project Scientist, 11 Principal Investigators, and more than 250 Co-Investigators from ESA Member States, the United States, Canada, China, the Czech Republic, Hungary, India, Israel, Japan, and Russia.
SOHO
The Solar and Heliospheric Observatory (SOHO) is stationed 1.5 million kilometres away from Earth. There, it constantly watches the Sun, returning spectacular pictures and data of the storms that rage across its surface. SOHO's studies range from the Sun's hot interior, through its visible surface and stormy atmosphere, and out to distant regions where the wind from the Sun battles with a breeze of atoms coming from among the stars. The SOHO mission is a joint ESA/NASA project.
What's special?
Every day SOHO sends thrilling images from which research scientists learn about the Sun's nature and behaviour. Experts around the world use SOHO images and data to help them predict 'space weather' events affecting our planet.
SOHO moves around the Sun on the sunward side of Earth, where it enjoys an uninterrupted view of the Sun, by slowly orbiting around Lagrange point L1. This a spot in space where the gravitational fields of the Sun and Earth cancel each other and keep SOHO in an orbit locked in line with the two bodies.
Discoveries include complex currents of gas flowing beneath the visible solar surface and rapid changes in the pattern of magnetic fields. In the Sun’s atmosphere, SOHO also sees explosions, remarkable shock waves and tornadoes.
Spacecraft
The total mass of the spacecraft at launch was 1850 kilograms. Its length along the sun-pointing axis is 4.3 metres, and the span of the extended solar panels is 9.5 metres.
The instruments on board SOHO are:
- CDS (Coronal Diagnostic Spectrometer) from Rutherford Appleton Laboratory, United Kingdom.
- CELIAS (Charge, Element, and Isotope Analysis System) from the University of Bern, Switzerland.
- COSTEP (Comprehensive Suprathermal and Energetic Particle Analyser) from the University of Kiel, Germany.
- EIT (Extreme ultraviolet Imaging Telescope) from the Institut d'Astrophysique Spatiale, France.
- ERNE (Energetic and Relativistic Nuclei and Electron experiment) from the University of Turku, Finland.
- GOLF (Global Oscillations at Low Frequencies) from the Institut d'Astrophysique Spatiale, France.
- LASCO (Large Angle and Spectrometric Coronagraph) from the Naval Research Laboratory, United States.
- MDI (Michelson Doppler Imager) from Stanford University, United States.
- SUMER (Solar Ultraviolet Measurements of Emitted Radiation) from the Max-Planck-Institut für Aeronomie, Germany.
- SWAN (Solar Wind Anisotropies) from Service d'Aeronomie, France.
- UVCS (Ultraviolet Coronagraph Spectrometer) from Harvard-Smithsonian Center for Astrophysics, United States.
- VIRGO (Variability of Solar Irradiance and Gravity Oscillations) from PMO/WRC Davos, Switzerland.
Journey
SOHO had such a flawless launch in 1995, that it had to use only very little thruster fuel for course corrections during its journey out to its operating position L1.
SOHO was meant to operate until 1998, but it was so successful that ESA and NASA decided to prolong its life several times and endorsed several mission extensions. In its latest round of mission extensions, ESA approved continued SOHO operations until the end of 2014, subject to mid-term review in 2012.
Three years into its mission, in June 1998, contact was lost with SOHO after a sequence of incorrect commands during what should have been a routine manoeuvre. All attempts to re-establish contact with the spacecraft failed and no one knew where it was for four weeks.
In August 1998, a powerful radar signal from Earth produced a faint echo from the spacecraft. SOHO was still in the right place and angled in such a way that sunlight would begin to fall on its solar cells again during the following months, so enabling it to resume normal operations.
Other difficulties came with the loss of the gyroscopes used to control the spacecraft orientation. Despite these problems, engineers have kept SOHO functioning with all its instruments performing well. SOHO was the first three-axis stabilised spacecraft to be operated without any gyroscopes.
History
SOHO was first proposed 13 years before its actual launch and the roots of SOHO were laid in earlier studies, namely those of GRIST (Grazing Incidence Solar Telescope) and DISCO (Dual Spectral Irradiance and Solar Constant Orbited). It is the combination of the objectives of these two missions that constitutes the core of the SOHO mission.
In June 1976, GRIST had been competing with a 'Solar Probe' as well as other studies involving other disciplines for further study. Solar Probe envisaged a set of instruments on a spacecraft that would get close to the Sun. Although its assessment study cited four scientific disciplines interested in the mission, Solar Probe was not followed up at the time.
The GRIST study, on the other hand, proceeded to a feasibility stage. GRIST was preferred over Solar Probe because the wavelength range accessible through its optics was particularly useful for studying the hot outer solar atmosphere. GRIST was at that time being designed for flights on Spacelab.
Following the 1976 study, GRIST did not make it to project selection either. It was based on a collaboration with NASA which became a victim in 1981 of NASA's cancellation of the US probe in the International Solar Polar Mission (ISPM, the former 'Out-of-Ecliptic Mission', now called Ulysses). GRIST was 'parked', but restricted studies on its main spectrometers were supported by ESA.
In 1980, a group of French and American physicists observed the Sun continuously from Antarctica, studying solar physics with the best conditions available on Earth. These historic observations led to the decision to include the same sort of experiments on board a newly proposed mission called DISCO. DISCO would sit at the L1 Lagrange point between the Sun and Earth, which would be an ideal observing site. A miniaturised version of the South Pole experiment could be used as part of DISCO’s payload, provided its weight could be reduced.
DISCO was conceived as a fairly small and cheap spin-stabilised spacecraft, weighing no more than 520 kilograms. It was intended to prove that ESA could also undertake small and inexpensive missions. A first assessment was made in 1981, when DISCO had remained a relatively inexpensive spinning satellite, very similar to Cluster. ESA's Solar System Working Group preferred DISCO to a competing Mars mission called 'Keller', but DISCO eventually lost out to the Infrared Space Observatory in 1983.
SOHO itself developed as a mission in 1983, combining many of the aspects of the previously planned missions. It became important because it developed momentum, together with the Cluster mission, as part of the International Solar–Terrestrial Physics Programme. In May 1984, ESA identified SOHO as a part of the 'Cornerstone' of its long-term 'Horizon 2000' science programme.
Partnerships
SOHO is part of the first Cornerstone project in ESA's Science programme (the other is Cluster). Both are joint ESA/NASA projects in which ESA is the senior partner. SOHO and Cluster are also contributions to the International Solar-Terrestrial Physics Programme, to which ESA, NASA, Japan, Russia, Sweden and Denmark all contribute satellites monitoring the Sun and solar effects.
Of the spacecraft's 12 instruments, nine come from multinational teams led by European scientists, and three from US-led teams. More than 1500 scientists from around the world have been involved with the SOHO programme.
SOHO was built by industrial companies in 14 European countries, led by Matra-Marconi (now Astrium). The service module, with solar panels, thrusters, attitude control systems, communications, and housekeeping functions, was prepared in Toulouse, France. The payload module carrying the scientific instruments was assembled in Portsmouth, United Kingdom, and mated with the service module in Toulouse, France. NASA launched SOHO and is responsible for tracking, telemetry reception, and commanding.
Venus Express
| How the mission was named: | The name Venus Express comes from the short time to define, prepare and launch the mission. It took less than three years from the approval to the launch of the mission. To do this, ESA re-used the same design as the Mars Express mission and the same industrial teams that worked on that mission. |
| Prime contractor: | EADS Astrium, Toulouse, France, leading a team of 25 subcontractors from 14 European countries. |
| Launch date: | 9 November 2005 (Soyuz-Fregat from Baikonur, Kazakhstan). |
| Launcher: | Soyuz/Fregat, built by Starsem, the European/Russian launcher consortium |
| Launch mass: | 1270 kg (including 93 kg orbiter payload and 570 kg fuel) |
| Orbiter instruments: | Venus Monitoring Camera (VMC); Analyser of Space Plasma and Energetic Atoms (ASPERA); Planetary Fourier Spectrometer (PFS); Visible/Ultraviolet/Near-infrared Mapping Spectrometer (VIRTIS); Venus Express Magnetometer (MAG); Venus Radio Science Experiment (VeRa); Ultraviolet and Infrared Atmospheric Spectrometer (SPICAV/SOIR); |
| Spacecraft operations: | European Space Operations Centre (ESOC), Darmstadt, Germany |
| Ground stations: |
After launch, ground stations at Villafranca (15 m), Spain, New Norcia (35 m), Australia, and Kourou (15 m), French Guiana, will be used for communication and orbit determination.
At Venus, Cebreros (35 m) near Madrid, Spain. The New Norcia antenna will be used to support the Venus Radio science experiments.
|
| Arrival at Venus: | April 2006 |
| Journey:
The launcher placed the spacecraft into a transfer orbit to Venus. It will travel through space for 155 days and, once it is captured by Venusian gravity, it will take five days to manoeuvre into its operational orbit.
|
Venus Express firsts:
|
| Summary:
Venus Express will study our nearest planetary neighbour. It has been built around the design of Mars Express, making it quicker and cheaper to develop. In particular, Venus Express will study the Venusian atmosphere and clouds in unprecedented detail and accuracy. It is ESA's first spacecraft to visit this planet.With Venus Express, Mars Express and BepiColombo, ESA is the only space agency in the world with current plans to visit each planet in the inner Solar System.
|
Mars Express
| How the mission was named: | Mars Express is so called because it will be built more quickly than any other comparable planetary mission. Beagle 2 was named after the ship in which Charles Darwin sailed when formulating his ideas about evolution. |
| Prime contractor: | Astrium, Toulouse, France, leading a consortium of 24 companies from 15 European countries and the US |
| Launch date: | 2 June 2003 |
| Launcher: | Soyuz/Fregat, built by Starsem, the European/Russian launcher consortium |
| Launch mass: | 1120 kg (including 113 kg orbiter payload and 60 kg lander) |
| Lander: | Beagle 2 |
| Orbiter instruments: | High Resolution Stereo Camera (HRSC); Energetic Neutral Atoms Analyser (ASPERA); Planetary Fourier Spectrometer (PFS); Visible and Infra Red Mineralogical Mapping Spectrometer (OMEGA); Sub-Surface Sounding Radar Altimeter (MARSIS); Mars Radio Science Experiment (MaRS); Ultraviolet and Infrared Atmospheric Spectrometer (SPICAM); |
| Spacecraft operations: | European Space Operations Centre (ESOC), Darmstadt, Germany |
| Ground stations: | ESA ground station in New Norcia, near Perth, Australia. Foreseen operational duration: One Martian year (687 Earth days) is funded. The spacecraft is designed for a further Martian year's operation. |
| Arrival at Mars: | December 2003 |
| Lander mission management: | University of Leicester, UK |
The Mars Express Orbiter will:
|
The Beagle 2 lander was planned to:
|
ESA programs :
GAIA :
| LAUNCH DATE: | 2013 |
| MISSION END: | nominal mission end after 5 years (2018) |
| LAUNCH VEHICLE: | Soyuz-Fregat |
| LAUNCH MASS: | 2030 kg |
| MISSION PHASE: | Implementation |
| ORBIT: Lissajous-type orbit around L2 | |||
| OBJECTIVES: To create the largest and most precise three dimensional chart of our Galaxy by providing unprecedented positional and radial velocity measurements for about one billion stars in our Galaxy and throughout the Local Group. |
Un nou proiect, intitulat Gaia, va studia timp de 5 ani Calea Lactee, cartografiind întreaga galaxie şi obţinând răspunsuri la cele mai importante întrebări despre evoluţia şi structura sa. „Va fi fenomenal. Va schimba totul”, a declarat astronomul Barry F. Madore de la Observatorul Carnegie din Pasadena, California.
Dezvoltată de Agenţia Spaţială Europeană şi construită de EADS, naveta Gaia valorează 700 de milioane de euro. Gaia va fi doar cel de-al doilea satelit dedicat astrometriei (ştiinţa care se ocupă de studierea mişcărilor, poziţiilor şi distanţelor dintre diferite obiecte astronomice) lansat pe orbită. Astrometria este o ştiinţă practicată de câteva secole, însă acurateţea telescoapelor situate pe planeta noastră este limitată de turbulenţele atmosferice. Până acum, oamenii de ştiinţă au măsurat cu o precizie de 1% distanţa către mai puţin de 1.000 de stele. Cu Gaia, însă, cercetătorii estimează că vor putea măsura cu această fidelitate distanţa către mai bine de 10 milioane de stele. În cuvintele lui Timo Prusti, un cercetător implicat în acest proiect, „va fi o lovitură de baros pentru astronomia fundamentală”.
Naveta Gaia urmează să fie lansată în cursul acestui an din Kourou, Guiana Franceză, urmând să intre în orbită în punctul L2 (Lagrange 2), la 1,5 milioane de kilometri
PLANK & HERSCHEL:
Planck will offer vastly improved performance in measuring the Cosmic Microwave Background (CMB) radiation compared to balloon-borne and ground-based experiments and will exceed the performance of any previous space-based instruments of this kind.
The spacecraft revolves about its Sun-pointing axis once per minute to stabilise its attitude. Planck will use this stabilisation spin to scan the sky, observing at least 95% of it through two separate observation periods in a span of 15 months.
| The Planck spacecraft | |
|---|---|
| Dimensions | 4.20 x 4.22 m (height x width) |
| Mass | 1.95 tonnes at launch |
| Spacecraft | Spin stabilised, 1 rpm |
| Telescope mirror | 1.9 x 1.5 m primary reflector |
| Telescope mass | 205 kg with focal plane unit |
| Lifetime | A minimum of 15 months, limited by degradation of cooling system |
| Operational orbit | Lissajous orbit at an average distance of 400 000 km from L2 |
| Propulsion | Hydrazine, 12 thrusters x 20 N each, 4 thrusters x 1 Newton each |
| Solar arrays | Flat, fixed triple-junction Gallium-Arsenide cell panels on rear of spacecraft |
| Solar array area: 13m2 | |
| Batteries | 39 Ah lithium ion batteries |
Planck will study the Cosmic Microwave Background by measuring its temperature all over the sky. Planck’s large telescope will collect light from the CMB and focus it onto two arrays of radio detectors, which will translate the signal into a temperature reading.
The detectors on board Planck are highly sensitive. They will look for variations in the temperature of the CMB of about a million times smaller than one degree – this is comparable to measuring from Earth the heat produced by a rabbit sitting on the Moon.
The Planck spacecraft consists of two main elements: a warm satellite bus, or service module, and a cold payload module, which includes the two scientific instruments and the telescope.
The service module is octagonal in shape. It houses the data handling systems and subsystems essential for the spacecraft to function and communicate with Earth, and the electronic and computer systems of the instruments. At the base of the service module is a flat, circular solar panel that generates power for the spacecraft and protects it from direct solar radiation.
The baffle is an important part of the payload module. It surrounds the telescope, limiting the amount of stray light incident on the reflectors. It also helps radiate excess heat into space, cooling the focal plane units of the instruments and the telescope to a stable temperature of about –223ºC (or 50 K). The baffle forms part of the passive cooling system for the satellite, which supports the active cooling system.
The solar array, located at the bottom of the service module at one end of the spacecraft, is permanently illuminated by sunlight. Three reflective thermal shields isolate the service module from the payload module at the opposite end. This prevents heat generated by the solar array and the electronic boxes inside the service module from diffusing to the payload module.
This passive cooling system brings the temperature of the telescope down to around 50 K. The temperature of the detectors is further decreased to levels as low as 0.1 K by a three-stage active refrigeration chain. The resulting difference in temperature between the warm and cold ends of the satellite is an astounding 300 K.
| 3 x low gain antennae 1 x medium gain antenna |
http://youtu.be/Es4sjgq-_EE
JWST :
The James Webb Space Telescope (JWST) is designed to expand the scientific success of the Hubble Space Telescope. Being a 'cool' telescope, JWST is designed to operate at very low temperatures (around -230° C). This will give it an unprecedented view of the Universe at infrared wavelengths and will allow it to observe a wide variety of celestial objects, ranging from planets in the Solar System to nearby stars, from neighbouring galaxies to galaxy clusters, and out to the farthest reaches of the very distant Universe. It is planned to operate for five years, possibly ten.
What’s special?
JWST is also very big, as its primary mirror has an area seven times larger than that of Hubble, which will make it much more sensitive. JWST will combine superb image quality, a large field of view, and a low level of background light with a highly stable environment away from the turbulence of the Earth's atmosphere that blurs images collected on the ground. All of these characteristics set JWST apart from other existing or planned observatories and will be instrumental in the search for the faintest stars and galaxies.
Spacecraft
JWST will be launched on board an Ariane V ECA rocket from the European Spaceport of Kourou, in French Guiana. One technical challenge is trying to pack a 6.5-m spacecraft into a 5 m diameter rocket, described as ‘a bit like designing a ship in a bottle’. Besides the telescope mirrors, the spacecraft, and the large sun shield, the JWST observatory has four scientific instruments mounted behind the telescope itself:
The Near Infrared Camera (NIRCam) is mainly designed for imaging studies and the detection of faint objects. The topics for which NIRCam will be invaluable include the search for the first stars, star clusters and galaxy cores that formed after the Big Bang; the study of far distant galaxies seen in the process of formation or merging; the detection of light distortion due to dark matter; the discovery of supernovae in remote galaxies; studies of the stellar population in nearby galaxies, of young stars in the Milky Way and of Kuiper Belt objects in our Solar System.
The Near-Infrared Spectrograph (NIRSpec) will obtain spectra of more than 100 galaxies or stars simultaneously and is sensitive over a wavelength range that matches the peak emission from the most distant galaxies. The key scientific objectives of NIRSpec are the study of star formation and chemical abundances of young distant galaxies; tracing the creation of the chemical elements back in time; exploring the history of the intergalactic medium, i.e. the gaseous material that fills the vast volumes of space between the galaxies; characterising the atmospheres of extra-solar planets.
The Mid-Infrared Camera and Spectrograph (MIRI) is an essential tool for studying extremely old and distant stellar populations; regions of intense star formation that are hidden behind thick layers of obscuring dust; hydrogen emission from previously unthinkable distances; the physics of protostars; Kuiper Belt objects and faint comets.
The Fine Guidance Sensor (FGS) will provide high-precision signals to the observatory to enable stable pointing at the milli-arcsecond level. It will also support star field identification via correlation with a star catalogue as well as spatial and radiometric calibrations.
Journey
JWST must be cooled so that the instruments’ own infrared emission cannot overwhelm the faint signals from observed objects. The JWST orbit will be 1.5 million km away from Earth, at Lagrange Point 2 (L2), so it must be extremely reliable, even though it is using new and innovative technology, because it will be too far away for astronauts to service it.
History
The James Webb Space Telescope was formerly known as the Next Generation Space Telescope (NGST). Due for launch on an Ariane 5, it will follow in HST’s footsteps. ESA has participated actively in both missions from the very beginning, bringing huge scientific benefits to European astronomers, while promoting competitiveness and cross-border collaboration within European science as a whole. NASA and ESA, joined by the Canadian Space Agency, have collaborated on JWST since 1997.
Partnerships
JWST is a partnership between ESA, NASA and the Canadian Space Agency.
Last update: 14 November 2011
HST - old Hubble for ya '
EUCLID :
How did the Universe originate and what is it made of?
Primary Goal
To understand the nature of dark energy and dark matter by accurate measurement of the accelerated expansion of the Universe through different independent methods.
Targets
Galaxies and clusters of galaxies out to z~2,
in a wide extragalactic survey covering 15 000 deg², plus a deep survey covering an area of 40 deg²
WavelengthVisible and near-infraredin a wide extragalactic survey covering 15 000 deg², plus a deep survey covering an area of 40 deg²
Telescope1.2 m Korsch
OrbitSecond Sun-Earth Lagrange point, L2
Lifetime6 years
TypeM-class mission
20 June 2012
ESA’s Euclid mission to explore the hidden side of the Universe – dark energy and dark matter – reached an important milestone today that will see it head towards full construction.
Selected in October 2011 alongside Solar Orbiter as one of the first two medium-class missions of the Cosmic Vision 2015–25 plan, Euclid received final approval from ESA’s Science Programme Committee to move into the full construction phase, leading to its launch in 2020.
The committee also formalised an agreement between ESA and funding agencies in a number of its Member States to develop Euclid’s two scientific instruments, a visible-wavelength camera and a near-infrared camera/spectrometer, and the large distributed processing system needed to analyse the data they produce.Finally, the committee agreed on a Memorandum of Understanding between ESA and NASA that will see the US space agency help to provide infrared detectors.Nearly 1000 scientists from 100 institutes form the Euclid Consortium building the instruments and participating in the scientific harvest of the mission.
“This formal adoption of the mission is a major milestone for a large scientific community, their funding agencies and also for European industry,” said Alvaro Giménez Cañete, ESA’s Director of Science and Robotic Exploration.
“This formal adoption of the mission is a major milestone for a large scientific community, their funding agencies and also for European industry,” said Alvaro Giménez Cañete, ESA’s Director of Science and Robotic Exploration.
“It took a lot of hard work to get this far, but we now have a solid blueprint for a feasible space telescope which enables very accurate measurements that will bring to light the nature of dark energy,” said Yannick Mellier, the Euclid Consortium lead.In the coming months, industry will be asked to make bids to supply spacecraft hardware, such as the telescope, power systems, attitude and orbit controls, and communications systems.Euclid will use a 1.2-m diameter telescope and the two instruments to map the 3D distribution of up to two billion galaxies and dark matter associated with them, spread over more than one third of the whole sky.Stretched across ten billion light-years, the mission will plot the evolution of the Universe’s structure over three-quarters of its history.Euclid is optimised to answer one of the most important questions in modern cosmology: why is the Universe expanding at an accelerating rate, rather than slowing down due to the gravitational attraction of all the matter in it?
The discovery of this cosmic acceleration in 1998 was rewarded with the Nobel Prize for Physics in 2011 and yet we still do not know what causes it.
The term ‘dark energy’ is often used to signify this mysterious force, but by using Euclid to study its effects on the galaxies and clusters of galaxies across the Universe, astronomers hope to come much closer to understanding its true nature and influence.“Euclid addresses the cosmology-themed questions of ESA’s Cosmic Vision and it’s fantastic that we are moving forward into the next stage of development – we’re one step closer to learning more about the Universe’s darkest secrets,” said René Laureijs, ESA’s Euclid project scientist.
Spacecraft
Introduction
The Euclid spacecraft will have a launch mass of around 2100 kg. It will be about 4.5 metres tall and 3.1 metres in 'diameter' (with appendages stowed). The nominal mission lifetime is six years.
The Euclid spacecraft will be made up of two major assemblies:
- payload module – houses the telescope, the focal plane components of the instruments and some of the data processing electronics;
- service module – contains the satellite systems: power distribution, attitude control, propulsion, telecommand, telemetry and data handling.
 |
Two spacecraft concepts have been studied during the assessment phase: (left) concept from EADS Astrium, and (right) concept from Thales Alenia Space. Credit: ESA
|
Euclid
Mission Status
The Euclid mission has been adopted with launch planned for 2020.
Euclid, a mission devised to provide insight into the nature of dark energy and dark matter by accurate measurement of the accelerated expansion of the Universe, emerged from two mission concepts that were proposed in response to the ESA Cosmic Vision 2015-2025 Call for Proposals, issued in March 2007: the DUNE - Dark Universe Explorer - mission proposed to measure the effects of weak gravitational lensing; the SPACE - Spectroscopic All Sky Cosmic Explorer - mission, aimed at measuring the baryonic acoustic oscillations and redshift-space distortion patterns in the Universe.
In October 2007 the ESA advisory structure selected both proposals to enter the assessment study phase, considering them as equally relevant to the investigation of dark energy. ESA then appointed a Concept Advisory Team with the task of identifying the best possible concept for the dark energy mission to be studied during this phase. This team recommended a combined mission which could simultaneously measure weak lensing and baryonic acoustic oscillations (BAOs). The new mission concept was called Euclid, honouring the Greek mathematician Euclid of Alexandria (~300 BC) who is considered as the father of geometry.
The ESA internal pre-assessment phase for Euclid ran from November 2007 until May 2008. The outcome of this study was a preliminary design for the Euclid mission and its payload which formed the basis for the Invitation to Tender that was issued to Industry in May 2008. A parallel competitive contract was awarded to EADS Astrium Friedrichshafen (Germany) and Thales Alenia Space (Italy); these industrial activities were concluded in September 2009.
Two instrument consortia responded to ESA's call for Declaration of Interest for payload studies issued in May 2008. The consortium for the visual and near-infrared imaging photometer for the weak-lensing experiment is led by A. Réfrégier from CEA Saclay. The consortium providing the NIR spectrometer for the Baryonic Acoustic Oscillations experiment is led by A. Cimatti from Bologna University. These studies ran from October 2008 until August 2009.
The report of the assessment study, which includes the Euclid science case together with a synthesis of the industrial and instrument consortium studies, was presented to the scientific community in December 2009. In addition, an independent technical review of the assessment study was conducted by ESA. The recommendations of the review board were presented to the scientific community also in December 2009.
In early 2010 ESA's Science Programme Committee recommended that Euclid, along with two other M-class candidate missions (PLATO and Solar Orbiter) proceed to the next phase: a more detailed definition phase during which period the cost and implementation schedule for the mission must be established. This detailed definition phase was completed in mid 2011.
In October 2011, Euclid was selected by the SPC as one of the first two medium-class missions of the Cosmic Vison 2015-2025 plan; Solar Orbiter was the other mission selected at the time. Euclid received final approval to move into the full construction phase at the SPC meeting in June 2012.
Science Goals
Euclid is an ESA mission to map the geometry of the dark Universe. The mission will investigate the distance-redshift relationship and the evolution of cosmic structures. It achieves this by measuring shapes and redshifts of galaxies and clusters of galaxies out to redshifts ~2, or equivalently to a look-back time of 10 billion years. It will therefore cover the entire period over which dark energy played a significant role in accelerating the expansion. |
Until about thirty years ago astronomers thought that the Universe was composed almost entirely of ordinary matter: protons, neutrons, electrons and atoms. In the intervening years the emerging picture of the composition of the Universe has changed dramatically. It is now assumed that ordinary matter makes up only about 4% of the Universe, and that the mass-energy budget of the Universe is actually dominated by two mysterious components: dark energy and dark matter.
Dark energy, which accounts for the vast majority (76%) of the energy density of the Universe, is causing the expansion of the Universe to accelerate. The existence and energy scale of dark energy cannot be explained with our current knowledge of fundamental physics.
 |
The Universe evolves from a homogeneous state after the big bang through cooling and expansion. The small initial inhomogeneities grow through gravity to produce the large-scale structures that we see today. Credit: Euclid Assessment Study Report
|
Euclid's cosmological probes
Euclid will map the large-scale structure of the Universe over the entire extragalactic sky - or half of the full sky excluding the regions dominated by the stars in our Milky Way. It will measure galaxies out to redshifts of ~2, which corresponds to a look-back time of about 10 billion years, thus covering the period over which dark energy accelerated the expansion of the Universe.Euclid is optimised for two primary cosmological probes:
- Weak gravitational Lensing (WL): Weak lensing is a method to map the dark matter and measure dark energy by measuring the distortions of galaxy images by mass inhomogeneities along the line-of-sight.
- Baryonic Acoustic Oscillations (BAO): BAOs are wiggle patterns, imprinted in the clustering of galaxies, which provide a standard ruler to measure dark energy and the expansion in the Universe.
 |
(Left) Illustrations of the effect of a lensing mass on a circularly symmetric image. (Right) In galaxy cluster Abell 1689, strongly lensed arcs can be seen around the cluster. Every background galaxy is weakly lensed.
|
 |  |
Illustration of the two primary cosmological probes of Euclid: weak gravitational lensing (left) and Baryonic Acoustic Oscillations (right).Credit: (right) NASA, ESA, and R. Massey.
| |
With its wide-field capability and high-precision design, Euclid will:
- Investigate the properties of the dark energy by accurately measuring both the acceleration as well as the variation of the acceleration at different ages of the Universe
- Test the validity of general relativity on cosmic scales
- Investigate the nature and properties of dark matter by mapping the 3-dimensional dark matter distribution in the Universe
- Refine the initial conditions at the beginning of our Universe, which seed the formation of the cosmic structures we see today.
Additional science with Euclid
Euclid will produce a massive legacy of deep images and spectra over at least half of the entire sky. This will be a unique resource for the astronomical community and will impact upon all areas of astronomy. Euclid’s spatial resolution of 0.2 seconds of arc is only achievable from space, and is comparable to the Hubble Space Telescope. With Euclid, the majority of the new sources identified by future imaging observatories, from radio to X-rays, will be readily associated to a known redshift, out to a redshift z~2. This adds an enormous power to the science return of these other projects, as it eliminates the time-consuming phase of redshift follow-up. Euclid will be a discovery machine on an unprecedented scale, and may well be the major feeder for more detailed studies both with ground-based facilities and future satellites.
INTEGRAL :
Integral is the first space observatory that can simultaneously observe objects in gamma rays, X-rays and visible light. Its principal targets are violent explosions known as gamma-ray bursts, powerful phenomena such as supernova explosions, and regions in the Universe thought to contain black holes.
Gamma rays are even more powerful and penetrating than the X-rays used in medical examinations. Fortunately, the Earth's atmosphere acts as a shield to protect us from this dangerous cosmic radiation.
This means that gamma rays from space can only be detected above the Earth’s atmosphere. Integral is the most advanced gamma-ray observatory ever launched. It can detect radiation from events far away and from the processes that shape the Universe.
History
Integral was selected by the ESA in June 1993 as the next ESA medium-size scientific mission (M2) of its Horizon 2000 programme. The mission was conceived as an observatory led by ESA with contributions from Russia (Proton launcher) and NASA (Deep Space Network ground station)
Standing 5 metres high and more than 4 tonnes in weight, the Integral spacecraft is impressive. The satellite has two main parts. The service module is the lower part of the satellite and contains all spacecraft subsystems. The payload module is mounted on the service module and carries the scientific instruments.
To limit the costs of the mission the service module is a rebuild of the one developed for XMM-Newton, ESA's X-ray Multi-Mirror satellite. It is a closed structure made of composite material, a combination of aluminium and carbon fibre. It houses the satellite systems, including solar power generation, power conditioning and control, data handling, telecommunications and thermal, attitude and orbit control.
The four scientific instruments of Integral's payload module weigh 2 tonnes, making this payload the heaviest ever placed in orbit by ESA. This is due to the need to shield the detectors from background radiation in order to make them sensitive. There are two main instruments detecting gamma rays. An imager will give the sharpest gamma-ray images so far. A spectrometer will gauge gamma-ray energies extremely precisely. Two other instruments, an X-ray monitor and an optical camera, will help to identify the gamma-ray sources.
There is a special support structure 4 metres above the platform with the instrument detectors. This carries so-called 'coded masks'. These metal masks produce the images of the gamma-ray sources. Since gamma rays cannot be focussed by conventional lenses or mirrors, Integral has to use an entirely different technique to make its images, known as the coded mask technique. A coded-mask telescope is a pinhole camera with not just one but many pinholes.
Light, or electromagnetic radiation, comes in many forms. There are radio waves, microwaves, infrared light, visible light, ultraviolet light, X-rays and gamma rays, all of which form what is known as the 'electromagnetic spectrum'.
Oddly enough, visible light – to which human eyes are sensitive - is the smallest band of radiation. To our eyes, what we see seems like the entire Universe; yet there is much more out there.
Different types of objects in the Universe emit different types of radiation. Our Sun is a rather obvious source of visible light. But it also glows in radio waves, infrared, ultraviolet light and X-rays. Some objects emit only radio waves or only X-rays. This is why it is important to study the Universe with various kinds of space observatories.
ESA’s Integral satellite is looking at the Universe, mainly concentrating on the gamma rays. These are produced by spectacular events in the Universe such as stars exploding, matter falling into black holes and celestial objects colliding. By collecting gamma rays, astronomers are able to see these violent events and can judge exactly how they shape the Universe.
For example, some chemical elements are created during explosions in which individual stars blow themselves to pieces. The new chemicals leave gamma-ray fingerprints in the fireball for astronomers to find. By studying these, Integral is piecing together how these chemicals are created.
Integral is also studying the mysterious blasts known as gamma-ray bursts. These explode at random in distant realms of the Universe and are probably caused by the collision of neutron stars (the hearts of dead stars) or may be the explosion of very massive stars.
Integral is designed to capture not just gamma rays but also X-rays and visible light. This complementary data is also helping astronomers identify the celestial object that is releasing the gamma rays and allow it to be more fully analysed.
Astronomical satellites register sudden bursts of gamma rays, always from a random direction, roughly once a day. These bursts may last a hundredth of a second, or anything up to 90 minutes. They become, briefly, the brightest objects in the gamma-ray sky but are never seen to repeat.
For over 20 years, astronomers had no clues about how far away these explosions occurred. Until in 1997, the Italian-Dutch satellite BeppoSAX provided accurate X-ray measurements so quickly that a burst’s location could be pinpointed, enabling follow-up observations with optical and other telescopes.
These observations confirmed that the gamma-ray bursts are extremely distant and therefore must be caused by tremendous explosions equal to the radiance of millions of millions of stars.
Where does this energy come from? This colossal amount of energy may be released when compact objects collide, such as neutron stars or black holes. Astronomers know of a small number of neutron stars in our galaxy that are in orbit around one another and may merge in the far future.
There is also mounting evidence that incredibly powerful supernovae, called ‘hypernovae’, are the source of the gamma-ray bursts.
Integral will be able to look at the glowing debris for the telltale signs of elements created when a star explodes.
XMM - NEWTON
XMM-Newton is detecting more X-ray sources than any previous satellite and is helping to solve many cosmic mysteries of the violent Universe, from what happens in and around black holes to the formation of galaxies in the early Universe. It is designed and built to return data for at least a decade.
It is the biggest science satellite ever built in Europe. Its telescope mirrors are the most sensitive ever developed in the world, and with its sensitive detectors, it sees much more than any previous X-ray satellite.
XMM-Newton’s high-technology design uses over 170 wafer-thin cylindrical mirrors spread over three telescopes. Its orbit takes it almost a third of the way to the Moon, so that astronomers can enjoy long, uninterrupted views of celestial objects.
What's special?
XMM-Newton has been able to measure for the first time the influence of the gravitational field of a neutron star on the light it emits. This measurement provides much better insight into these objects.
Neutron stars are among the densest objects in the Universe — a sugarcube-sized piece of a neutron star would weigh over a thousand million tonnes. Neutron stars are the remnants of heavy stars that end their life in a supernova explosion. In such cataclysmic events, most of the stellar matter is ejected into space (to eventually become the building blocks of all matter in the Universe, including ourselves). Part of what remains then collapses under its own gravity.
Scientists believe that, in a neutron star, the density and the temperatures are similar to those existing a fraction of a second after the Big Bang when the primordial soup of matter in the Universe was ‘broken’ into its most fundamental constituents. They assume that when matter is tightly packed as it is in a neutron star, it goes through important changes. Protons, electrons, and neutrons — the components of atoms — fuse together. It is possible that even the building blocks of protons and neutrons, the so-called quarks, get crushed together.
Scientists have spent the last decades trying to identify the nature of matter in neutron stars. To do this, they need to know some important parameters, very precisely. If you know a star’s mass and radius, or the relationship between them, you can obtain its density. However, no instrument was advanced enough to perform the measurements needed, until now. Thanks to ESA’s XMM-Newton observatory, astronomers have been able to obtain the mass-to-radius ratio of a neutron star for the first time and acquire the first clues about its composition. These clues suggest that neutron stars contain normal, non-exotic matter, although they are not conclusive. Scientists say this is a ‘key first step’ and that they will keep on with the search.
This measurement was a first in astronomical observation and it is considered a huge achievement. The method consists of determining the compactness of the neutron star in an indirect way. The gravitational pull of a neutron star is immense — thousands of million times stronger than the Earth’s. This makes the light emitted by the neutron star lose energy. This energy loss is called a gravitational ‘redshift’. The measurement of this redshift by XMM-Newton indicated the strength of the gravitational pull, and revealed the star’s compactness.
Spacecraft
XMM-Newton's name comes from the design of its mirrors, the highly nested X-ray Multi-Mirrors. These are enabling astronomers to discover more X-ray sources than with any of the previous space observatories. In one day, XMM-Newton sees more sources in a small area than one of the earliest X-ray satellites UHURU found across the whole sky during its three years in operation.
However, the programme also has a more formal name: the High-Throughput X-ray Spectroscopy Mission. Spectroscopy, the spreading of light into a spectrum, allows astronomers to measure a source’s composition. In the same way the colour of a lamp indicates what gas is used in street lighting, the three scientific instruments on board XMM-Newton will reveal the deepest secrets of a source, its chemical composition, temperature, and even the velocity of the source.
XMM-Newton can change its orientation extremely precisely using two sets of four small thrusters that use hydrazine gas and four momentum wheels mounted on the spacecraft are the primary means to control its attitude. It builds on the system which previously flew on the ISO mission, and is now also in use on the Integral mission.
Journey
XMM-Newton, in its 48-hour orbit, travels to nearly one third of the distance to the Moon. At the apogee (furthest point) of 114 000 kilometres away from Earth, the satellite travels very slowly. At the perigee (closest point) it passes 7000 kilometres above Earth much faster at 24 120 kilometres per hour. XMM-Newton’s highly eccentric orbit has been chosen so that its instruments can work outside the radiation belts surrounding the Earth.
The orientation of a satellite in space is crucial, whether for telecommunications, Earth observation or for astronomy missions. XMM-Newton will be targeting distant X-ray sources for long periods (often more than ten hours) and one of the key requirements of the satellite is its very high pointing accuracy and stability.
While orbiting the Earth in its highly elliptical orbit, XMM-Newton is steered to point its telescope towards targets selected by astronomers. The 3.8-tonne satellite slowly turns towards these celestial objects at a rate of 90 degrees per hour.
The pointing accuracy of the 10-metre long XMM-Newton is 0.25 arcsec over a 10-second interval. This is the equivalent of seeing a melon from a distance of 300 kilometres, using a handheld telescope and seeing it without the slightest wobble!
History
Before the late 1970s, only four galaxies had been detected emitting X-rays: the Milky Way, M31, and the Magellanic Clouds. Building on earlier work in the field, ESA’s X-ray observatory, Exosat, was launched in May 1983. It was active until April 1986, by which time it had made 1780 X-ray observations.
In 1982, an ‘X-ray Multi-Mirror’ astronomy mission was proposed. In 1984, a group of European scientists developed the ‘Horizon 2000’ long-term plan for ESA’s scientific programme. The idea was to achieve a 50% increase in the annual science budget over the following five years. Central to this plan was the concept of four ‘Cornerstones’ — large-scale missions whose scientific objectives would be achievable. The second Cornerstone was to be a ‘High Throughput X-ray Spectroscopy’ mission, or XMM by another name.
Serious work on XMM started in 1985 with the establishment of a number of working groups. The overall configuration was developed by 1987, looking very much like XMM as we know it today. Following the experience with Exosat, which demonstrated the value of a highly eccentric orbit for long uninterrupted observations of X-ray sources, XMM was to be placed in a 48-hour period orbit using the Ariane 4 launcher. The payload now featured only four X-ray mirror systems. However a very important feature had been added — the Optical Monitor — an instrument to allow simultaneous observation of the field of view the X-ray telescopes in the UV and visible bands. This was a lesson learned from the operation and exploitation of Exosat. An important part of XMM-Newton is that all instruments work in parallel — this is an extremely important tool in making the observatory more efficient.
ESA approved the mission in this form in June 1998. One year later the selection of the instruments and the long hardware development programme began. The Survey Science Centre was selected by ESA in 1995 to develop the processing of the XMM data.
XMM-Newton launched at the end of 1999.
Partnerships
The instruments have been conceived and built by European scientific institutes, and are each managed by a Principal Investigator (PI), heading teams of scientists and engineers from different countries. Overseeing the science of the entire mission is ESA’s XMM-Newton Project Scientist.
Abonați-vă la:
Postări (Atom)