Gaia – Soyuz-STB/Fregat-MT (VS06) – Куру/Синнамари – 20.12.2013 09:12 UTC

Автор ESA Vega, 18.12.2009 02:58:06

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PIN

Посмотрел я. Откуда "ноги" - знаю. И потому не доверяю :)

Morin

ЦитироватьChilik пишет:
ЦитироватьОчередное отставание или у "Астрометрии" есть не замеченные (не понятые) мной преимущества?
Половинка вторая. В науке принято иметь независимое подтверждение результатов. Хотя бы для того, чтобы иметь реальное представление об имеющихся погрешностях. Я слегка в курсе того, что творится в физике элементарных частиц. Если взять сборник Particle Data Group, то там для некоторых частиц приводятся, к примеру, значения массы, определённые в разных научных центрах. Часто эти результаты отличаются на 3-4-5 стандартных отклонений. И это притом, что в физике частиц народ с детства приучен к параноидально-педантичному отношению к погрешностям эксперимента. Так что пусть лучше будет дублирующий результат.
Верное мнение :-) ПМСМ. А то вот Гиппаркоса хвалят, а тут в теме никто не обмолвился ни словечком, что независимая проверка наземными астрономами измерений Гиппаркоса обнаружили огромные расхождения с контрольными замерами. По тем звездам, естественно, по которым можно было проверить. И что? Как теперь относиться к мегатомам результатов Гиппаркоса? Поэтому пусть будут параллельные независимые измерения. А то кроме авторов никто ничего не понимает. А будут независимые замеры, пусть даже на порядок более грубые, достоверность измерений можно будет однозначнго подтвердить или опровергнуть.
Лучшее - враг хорошего

ZOOR

"Астрометрии" в планах, скорректированных по итогам полета Ф-Г, уже не прослеживается :(
Я зуб даю за то что в первом пуске Ангары с Восточного полетит ГВМ Пингвина. © Старый
Если болит сердце за народные деньги - можно пойти в депутаты. © Neru - Старому

Morin

ЦитироватьZOOR пишет:
"Астрометрии" в планах, скорректированных по итогам полета Ф-Г, уже не прослеживается  :(
Очень жаль. Достойная задача и для ученых и для инженеров. И не надо тут гнаться за миллиардами наблюдений. Главное, чтоб они были достоверные и проверяемые. А то и так среди физиков астрофизики не пользуются репутацией надежных исследователей. (Это мне один знакомый физик сказал :-) ) Объекты исследований - далеко, прямо не померишь, а косвенные методы - каждый  трактует как ему удобно.
Лучшее - враг хорошего

Salo

#44
Цитировать
Цитировать
ЦитироватьSalo пишет:
Уже декабрь.
SOE пишет:
Откуда информация? Миссия готовится к пуску в октябре. Дату не скажу  :)
SOE пишет:
Посмотрел я. Откуда "ноги" - знаю. И потому не доверяю  :)  
А Galileo в декабре?
"Были когда-то и мы рысаками!!!"

Salo

#45
http://sci.esa.int/gaia/51921-11-gaia-flight-model-mass-properties-testing/
Цитировать#11: Gaia Flight Model Mass Properties Testing

 17 June 2013 12:33
 The Gaia Spacecraft Flight Model has successfully completed its mass properties test campaign.
    The mass properties of a spacecraft (total mass, centre of gravity [CoG] and moment of inertia [MoI] about all three axes) are among the characteristics calculated during the design process. Since the correct control and guidance of the spacecraft depend on an accurate knowledge of these values, they are subsequently measured as part of the test campaign. The integrated Gaia Flight Model (FM) spacecraft has completed its mass properties test campaign at the premises of Intespace in Toulouse, France.
    Measurement of the mass ensures that the completed spacecraft has a total mass that is within the design tolerances. This value is important for the launch, spin-up and injection into the transfer orbit to reach the operational orbit at the second Lagrange point of the Sun-Earth system (L2). A weighing scale was used to determine the spacecraft's mass with an accuracy of 0.4 kg.
       


Top left: Gaia spacecraft on the weighing scale for total mass measurement. Top right, lower left and lower right: Gaia spacecraft being lifted from the weighing scale.
Credit: ESA/Stefan Corvaja
          
Determining the location of the CoG of the spacecraft confirms that it is located within the design tolerances. Knowledge of the CoG position is important because it dictates how the spacecraft will behave when the sets of chemical and micropropulsion thrusters are fired asymmetrically, to rotate the spacecraft, rather than symmetrically, to change velocity. The CoG position was determined to approximately 2 mm for the X-axis, and approximately 0.35 mm for the Y and Z axes.
    Measuring the MoI about each of the spacecraft's axes and deriving the Products of Inertia (PoI) is performed so that its 'resistance' to rotation about any axis is available for refining the algorithms that the Attitude and Orbit Control System (AOCS) uses to control the spacecraft's orientation by firing the chemical or micropropulsion thrusters. The MoI about the X-axis was determined with an accuracy of  better than 10 kg m², and better than 30 kg m² for the Y and Z axes.



The Gaia spacecraft being lifted from its ground handling trolley, which was used to rotate the spacecraft through 90° ready for testing in a horizontal position. Credit: ESA/Stefan Corvaja          
    

                            
The Gaia spacecraft being installed on the mass properties testing equipment in a horizontal position.
Credit: ESA/Stefan Corvaja    

About Gaia

Gaia will create a three-dimensional map of the Milky Way, in the process revealing information about its composition, formation and evolution. The mission will perform positional measurements for about one billion stars in our Galaxy and Local Group with unprecedented precision, together with radial velocity measurements for the brightest 150 million objects. Gaia is scheduled to launch in 2013 for a nominal five-year mission, with a possible one-year extension.
The spacecraft will operate in a Lissajous orbit around the second Lagrange point of the Sun-Earth system (L2). This location in space offers a very stable thermal environment, very high observing efficiency (since the Sun, Earth and Moon are all behind the instrument FoV) and a low radiation environment. Uninterrupted mapping of the sky will take place during the operational mission phase.
The Prime Contractor for Gaia is Astrium SAS, based in Toulouse, France.
 
 Last Update: 17 June 2013
"Были когда-то и мы рысаками!!!"



Salo

#48
http://www.esa.int/Our_Activities/Space_Science/Gaia/Europe_bids_Gaia_a_safe_journey
Цитировать           
 
 Gaia scanning the sky
 Access the video
 
 27 June 2013 ESA's billion-star surveyor, Gaia, has completed final preparations in Europe and is ready to depart for its launch site in French Guiana, set to embark on a five-year mission to map the stars with unprecedented precision.
 Gaia's main goal is to create a highly accurate 3D map of our Milky Way Galaxy by repeatedly observing a billion stars to determine their precise positions in space and their motions through it.
 Other measurements will assess the vital physical properties of each star, including its temperature, luminosity and composition.
 The resulting census will allow astronomers to determine the origin and the evolution of our Galaxy.
 Gaia will also uncover tens of thousands of previously unseen objects, including asteroids in our Solar System, planets around nearby stars, and exploding stars – supernovas – in other galaxies.
 "Gaia will be ESA's discovery machine," says Alvaro Giménez, ESA's Director of Science and Robotic Exploration.
 "It will tell us what our home Galaxy is made of and how it was put together in greater detail than ever before, putting Europe at the forefront of precision astronomy.
 "Gaia builds on the technical and scientific heritage of ESA's star-mapping Hipparcos mission, reflecting the continued expertise of the space industry and the scientific community across Europe.
 "It's extremely rewarding to see the next generation of our high-precision observatories built and ready to answer fundamental questions about the cosmos."

  Gaia mapping the stars of the Milky Way
 
 Gaia will be launched later in 2013 on an Arianespace Soyuz rocket from Europe's Spaceport in Kourou, French Guiana, and will map the stars from an orbit around the Sun, near a location some 1.5 million km beyond Earth's orbit known as the L2 Lagrangian point.
 During its five-year mission, the spacecraft will spin slowly, sweeping its two telescopes equipped with the largest digital camera ever flown in space – with nearly a billion pixels – across the entire sky.
 Gaia will measure a billion stars, roughly 1% of all the stars spread across the Milky Way.
 As Gaia moves around the Sun, it will repeatedly measure the position of each star, allowing it to determine the distance through a perspective effect known as parallax.
 Combined with the other measurements, these data will equip astronomers with the information they need to reconstruct the history of the Milky Way.
 The mission will also discover new asteroids in our own Solar System and planets orbiting around other stars.
 Gaia should even be able probe the distribution of dark matter, the invisible substance that is detected only through its gravitational influence on celestial objects.
 It will test Einstein's General Theory of Relativity by watching how light is deflected by massive objects like the Sun and its planets, as well as other stars.
"Были когда-то и мы рысаками!!!"

Salo

#49
http://www.spacenews.com/article/civil-space/36006europe%E2%80%99s-star-mapping-gaia-satellite-finally-launch-pad-bound#.Uc1HM9iBXTo
ЦитироватьEurope's Star-mapping Gaia Satellite Finally Launch Pad-bound
By Peter B. de Selding | Jun. 27, 2013


Seven years in development and 13 years after it was formally approved by European space scientists, Gaia will provide an order-of-magnitude improvement over the performance of Europe's Hipparcos satellite. Credit: Astrium photo

TOULOUSE, France — Europe's Gaia satellite, designed to provide a 3-D map of 1 billion stars in the Milky Way and plot their movement, mass, composition and age, is set to leave its manufacturing site here Aug. 2 to prepare for a late October launch on a Europeanized version of Russia's Soyuz rocket.
Seven years in development and 13 years after it was formally approved by European space scientists, Gaia will provide an order-of-magnitude improvement over the performance of Europe's Hipparcos satellite, which was launched in 1989 and produced a map of 100,000 stars.
The Gaia industrial contracting team, led by Astrium Satellites, wrapped up final satellite tests June 26 and will now prepare it for shipment to Europe's Guiana Space Center on the northeast coast of South America.
Giuseppe Sarri, Gaia project manager at the 20-nation European Space Agency (ESA), said Gaia will be shipped to the spaceport even if there are more tests to be done, in part to secure the launch date, tentatively set for Oct. 25.
Europe's Soyuz manifest has been the subject of a competition among payloads this year as originally six missions were planning liftoffs when only four Soyuz rockets were available in 2013.
While the Gaia satellite is of modest size, just 2,030 kilograms at launch, it is an example of Big Science enabled by Big Data.
Mapping a billion stars, each fr om 70 separate observations made over Gaia's 4.5-year observing life fr om the L2 Lagrangian point around the sun 1.5 million kilometers from Earth, means 40 million observations per day.
To handle the data flow estimated at 40 gigabytes per day, or more than one petabyte, or 1 million gigabytes, over the mission's life, a multination Data Processing and Analysis Consortium (DPAC) has been created. Six data-processing centers have been established in Europe.
It will need massive parallel computing power. Francois Mignard of DPAC said during a Gaia preshipment press briefing here at Astrium Satellites' facility that spending only one second to process the data on each star swept up in Gaia's view would take 30 years to process.
Gaia's current budget is estimated at about 940 million euros, or $1.24 billion. ESA is paying 740 million euros to build and launch the satellite, and operate it for five years in orbit. Another 200 million euros has been spent over six years by the DPAC consortium, Mignard said, with more to come as Gaia reaches orbit and begins sending down data.
The mission originally was scheduled for launch in late 2011. But despite being nearly two years late, it is only over budget by about 16 percent, according to Sarri.
Even that figure is exaggerated since nearly half of the budget overrun was caused by the increased cost of the Europeanized Soyuz medium-lift rocket. Sarri said ESA had penciled in a 40-million-euro cost for the Soyuz when Gaia was approved, using the price ESA paid for a Soyuz launch of the agency's Mars Express satellite in 2003.
But that launch was from Soyuz's traditional launch site, the Russian-run Baikonur Cosmodrome in Kazakhstan. Launching from the European spaceport is more expensive. Sarri said the agency's originally forecast cost of 40 million euros swelled to around 65 million euros by the time the contract was signed in late 2009.
The remaining overruns were due to the payload module of Gaia. Sarri said ESA was able to lim it the financial costs of the two-year delay by waiting until the last minute to ramp up ESA's own Gaia team. When it became clear that Gaia would miss its 2011 launch date by a wide margin, the agency maintained its lim ited-size Gaia team. That way, he said, ESA's program management charges did not swell over the two-year period.
The Gaia payload module required three years of work by Astrium engineers to assemble, integrate and test to assure that the optical alignment to within a few microns of precision was up to specifications, said Vincent Poinsignon, Astrium's Gaia project manager.
The satellite has a giga-pixel focal plane assembly and 106 CCD chips arranged in a half-meter-square mosaic.
Gaia's precision is made possible not only by its orbit — the stability of the L2 Lagrangian point is well-known — but also by a micropropulsion cold-gas system that took nearly eight years to develop. The thrusters expel 1.5 micrograms of nitrogen per second to provide satellite attitude control.
If it works as planned, Gaia's focus will be sharp enough to be able to view a human hair at a distance of 1,000 kilometers.
"Были когда-то и мы рысаками!!!"


Salo

http://www.theengineer.co.uk/aerospace/in-depth/gaia-the-cosmic-camera-that-will-chart-a-billion-stars/1016691.article
ЦитироватьGaia: the cosmic camera that will chart a billion stars
  11 July 2013 | By Stuart Nathan
                          
                                        Humanity has been looking at the stars since its earliest days, and some of the greatest leaps in science have come as a result of stargazing. Indeed, astronomy was at the heart of the origin of what we now know as the scientific method, with such names as Flamsteed, Newton, Halley, Wren and Boyle involved in producing what was then the most comprehensive star catalogue, listing the positions of 3,000 stars.

The Milky Way blazes above the European Southern Observatory (ESO) facilities at Mount Paranal in northern Chile’s Atacama Desert. Paranal hosts the world’s most advanced ground-based astronomical observatory, the Very Large Telescope (VLT), and is ho

Position is vital for astronomy — you can't study a star if you can't find it. The science of star position is called astrometry and it's still a subject of intense research as we try to expand our understanding of our home galaxy, the Milky Way, and its history.
Like much astronomy, astrometry is now carried out by a combination of ground-based and space telescopes, and the latest astrometry mission will be carried out fr om space. A new space telescope called Gaia is currently undergoing its final preparations at EADS Astrium's cleanroom in Toulouse, before it is shipped out to the European Space Agency's launch site in Kourou, French Guiana, before going into service atop a Soyuz rocket.

Gaia will be the largest SiC instrument ever flown

Gaia represents a huge leap in astrometry. Its immediate predecessor, Hipparcos, measured the positions of two million stars during its mission in the early 1990s. Gaia's five-year mission will see it using a matched pair of telescopes to locate a billion stars, constructing the most detailed three-dimensional map of the Milky Way ever. Even this achievement will leave the vast majority of the galaxy as unmapped — a billion stars represents around one per cent of the total number in the Milky Way.
Like any scientific space mission, Gaia represents a series of firsts and superlatives. Its mirrors and optical bench — the structure its optical components are fixed to — are all made fr om the ceramic material silicon carbide, making it the largest SiC instrument ever flown. Its light-detecting sensors, made up fr om 106 charge-coupled devices (CCDs) mounted in a rectangular frame, make up the largest focal-plane array ever sent into space. It uses a new type of thruster to make minute corrections to its course without generating vibrations that could ruin its observations, and the information it will gather over the course of its mission represent one of the most challenging data-analysis projects ever.

Gaia's light-detecting sensors make up the largest focal-plane array ever sent into space

This combination of technologies adds up to an instrument of extreme sensitivity. Gaia's optics are capable of detecting an object the width of a human hair — around 17µm — fr om a distance of a thousand kilometres. This will allow it to not only detect and map extremely distant stars, but will also mean it will be able to spot the small movements of stars caused by planets rotating around them, thereby adding to the available techniques for detecting exo-planets.
This extreme sensitivity was the overriding factor in the spacecraft's design. Despite its spinning, tumbling course around its orbital (see 'Orbital manouevres' box), stability is everything to an optical instrument that can detect such minute detail. In this case, stability doesn't mean stillness; it means that all the system's optical components must retain their positions relative to each other within excruciatingly fine tolerances.
For the Astrium team building the satellite, at its locations in the UK, France, Germany and Spain, and its 50 subcontracting companies supplying components and subsystems, this posed a series of challenges. The need for stability dictated the choice of silicon carbide as the material for the mirrors and optical bench: strong, about twice as rigid as steel, and lightweight, it is also remarkably resistant to expansion and contraction under changes of temperature.

The instrument was designed to integrate individual components in line with the required level of accuracy and construction tolerances

Gaia contains two telescopes, with primary mirrors set at an angle of 106.5° to each other. These primaries, unlike the circular mirrors familiar fr om ground-based telescopes or space telescopes such as Hubble or Herschel, are rectangular in shape, 1.46m wide and 0.51m deep and convex. These each reflect light onto a pair of convex mirrors measuring 0.35m x 0.16m, which bounce the light onto another pair of concave mirrors and then onto a pair of flat mirrors. These combine the light fr om the two telescopes through another pair of flat mirrors so that the images from both fall together onto the focal plane array. This tortuous light path means that the effective focal length of the telescopes is 35m, despite the entire spacecraft's payload module being only 3.5m in diameter; this long focal length is instrumental in the telescopes' ability to see objects 400,000 times fainter than those visible to the naked eye.
The mirrors were all made by Boostec, a specialist company located not far from Toulouse, wh ere they were sintered from powdered SiC and ground so that their surfaces were flat.They were then sent on to another specialist, German firm Shunck Kohlenstofftechnik, wh ere they were coated with a fine layer of SiC by chemical physical vapour deposition; this layer, applied extremely evenly, could then be polished down to the extremely high-quality finish required, around 10nm RMS — for comparison, if the primary mirror were expanded to the size of the Atlantic Ocean, any imperfections on its surface would be a few centimetres high. Finally, additional layers of an enhanced silver coating were added using a process called physical vapour deposition.

The 10 mirrors and focal plane array are attached to a SiC optical bench structure that locks all the components into place

The focal plane array onto which these mirrors send their image consists of almost a billion pixels. The 106 CCDs from which it is composed were made by UK firm e2v, which has supplied most of the CCDs for space telescopes. The Chelmsford-based company produced a total of 174 CCDs for the project, including spares and engineering test models; each is 1,966 x 4,500 pixels and 45mm by 59mm. The array on Gaia itself, mounted onto a SiC frame, occupies an area of just under half a square metre.
Not all of the CCDs are dedicated to composing the spacecraft's final image. As both telescopes send their image to the same array, a strip of CCDs along the side of the array the image hits first work to detect which image came from which telescope, and to use this information to remove redundant images from the signal that is sent back to Earth.
The optical bench to which the 10 mirrors and focal-plane array are attached is another SiC construction, a toroidal structure that locks all the components into place with picometre (a thousandth of a nanometre) precision. Developed at the Dutch research organisation TNO, the optical bench presented some specific problems, according to TNO business development director Ben Braam. Previous instruments had been made from aluminium, which is somewhat flexible, he explained. 'While aluminium is able to absorb material stresses by deforming somewhat, silicon carbide just breaks, which meant that the whole design of the instrument has to remain below the breaking lim it,' he said. 'And clever design tricks have to be used to integrate individual components into the instrument in line with the required level of accuracy and construction tolerances.'


The need to avoid vibration meant that absolutely no mechanical components could be used on the satellite. This, explained Astrium project director Vincent Poisignon, meant that all of the spacecraft's cooling had to be completely passive: a marked contrast to most of the satellites that Astrium designs and builds, which operate in Earth orbit wh ere they are subject to large temperature swings as they move in and out of sunlight. These incorporate sophisticated systems to shuttle heat away from sensitive components and into structures designed to dissipate energy into space.
Gaia operates in a much more stable temperature environment, but its payload module needs to remain at a constant temperature of -110°C. 'That's all done by insulation,' Poisignon said. 'The sunshade does a lot of the work, but once the satellite is on station at L2 we just have to wait for the temperature to stabilise. The payload module is thermally separated from the service module, which contains all the fuel and auxiliary systems.' The satellite's solar panels are fixed to the base of the sunshield and the bottom of the spacecraft itself.

Orbital manoeuvres
Gaia's location will give it an unrivalled view of the Earth's galactic neighbourhood
Gaia is to be stationed at the prime near-Earth point for astronomical observation, the Lagrange 2 (L2) point, 1.5million miles from Earth. Lagrage points occur wh ere the graviational fields of several massive objects — in this case, the Earth, Moon and Sun — are in balance with each other, so a spacecraft can be positioned at them and keep its position with minimal use of thrusters. L2 is attractive for astronomy because it is on the opposite side of the Earth from the Sun, and therefore optical instruments don't have to cope with solar glare; It is also a stable, and relatively low, radiation environment.
Gaia is equipped with a large sunshield, 10m wide, which sits on the base of the cylindrical body of the spacecraft giving it the appearance of a large hat. At L2, this shades the craft from the light of the Sun, Earth and Moon, keeping the satellite at a steady temperature and providing a stable operating environment for its instruments. The L2 point was also home to the Planck and Herschel space telescopes until they recently completed their missions, and will be the base for NASA's successor to the Hubble Telescope, the James Webb Space Telescope. But it isn't a crowded location. In fact, spacecraft orbit around the L2 point in a course known as a Lissajous orbit. In Gaia's case, this is a key part of the mission. The satellite will spin, scanning its telescopes around a strip of the sky; it will also tumble as it orbits around L2, rotating this strip around the sky to give it a complete view of its surroundings.

The choice of thrusters was also dictated by the need to use no mechanical components. While normally satellites use small chemical thusters — effectively tiny versions of the main engines — this would have generated far too much vibration. Gaia requires constant course correction to keep in its optimum observing position, so ESA decided to develop a new type of cold gas thruster that uses nitrogen as its working fluid. Using piezoelectric actuators to control the flow of gas, these can exert a force as small as a micronewton. 'You need very little force, but the control has to be absolutely precise,' Poisignon said. 'And these thrusters operate constantly; they have to be totally reliable.'
Developed by a division of Thales Alenia Space, which has since been acquired by Selex, the thrusters took eight years to perfect. They are now set to be used on another ESA space-science mission, LISA Pathfinder, which aims to prove the concept behind the LISA mission to detect gravitational waves by monitoring the distances between three satellites flying in closely controlled formation.
Gaia puts Europe at the forefront of space telescope technologies, said Alvaro Giménez, ESA's director of science and robotic exploration. 'Gaia builds on the technical and scientific heritage of ESA's star-mapping Hipparcos mission, reflecting the continuing expertise of the space industry and the scientific community across Europe,' he said. 'It's extremely rewarding to see the next generation of our high-precision observatories built and ready to answer fundamental questions about the cosmos.'

The mapping mission
Gaia will determine the precise position of a billion stars
During its five years operating in space — which could be extended for as long as the spacecraft has enough fuel on board to maintain its observing position — Gaia will carry out a series of studies using its paired telescopes and three on-board instruments. Its primary task will be star-mapping.
The method it will use to determine the precise distance to remote stars is the same one that early naked-eye astronomers, before Galileo, used: parallax. The only direct method for measuring stellar distances, this works by taking measurements from two points, the distance between which is known precisely.
Parallax is best demonstrated by looking at a fixed object with one eye closed, then closing that eye and opening the other. The object appears to move, and the closer it is, the more it moves. Because we can measure the distance between our eyes, we can relate the apparent distance the object moves to the angle at the tip of a triangle formed by both eyes and the object.
Gaia will perform the same calculation by observing that same star at two points of the year, six months apart. The closer the star is, the more its distance will appear to have changed. But because of the vast distances between stars, the parallax angles are tiny — even for the nearest stars, it's less than one arc-second. This is why precision measurement is so vital for Gaia — the apparent parallax shift for distant stars is minute.
It's this sensitivity which gives Gaia its exo-planet spotting ability. Strictly speaking, planets don't orbit stars — stars and planets orbit each other, around a centre of gravity closer to the more massive object. As stars are much more massive than planets, effectively this means that planets make their home stars wobble. Gaia will be able to spot this wobble, analyse it, and by combining this information with the mass of the star, work out how big its exoplanet or planets are, and how far away they are from the star. Gaia is expected to see around 2000 exoplanets.
As well as measuring the distance to the stars, Gaia will also analyse their light using spectrometry. This will yield several pieces of information: the composition of the stars, determined by the characteristic wavelengths that make up their light; their temperature; and their mass.
Another instrument, the Radial Velocity Spectrometry, looks at a narrow range of the spectrum in high resolution to determine their Doppler Shift, which shows how fast the star is moving along its line of sight from Gaia. Because this movement can be 'run backwards', it will reveal clues to the galaxy's history — how the stars moved into the current positions, wh ere they originally formed, and the structure of the galaxy in its youth. And as the movement of stars is influenced by the mass of surrounding bodies, it could also give new insights into dark matter — the mysterious substance which makes up most of the mass of the universe, but emits no radiation and is therefore undetectable directly.
But Gaia's focal plane array isn't selective to stars — it'll see anything that drifts across the telescopes' field of view. This includes bodies within our own solar system such as comets and asteroids. In particular, it will be able to see asteroids close to the Sun, which ground based telescopes can't detect; and so-called 'Trojan' asteroids trapped in the gravity wells of planets. These could give new information about the formation of the solar system.
Finally, Gaia will give astrophysicsts a chance to for the most extensive test yet of one of Albert Einstein's theories — the bending of light by massive objects. Stars whose light has to pass close to the Sun and Jupiter is bent by the mass so they appear in a different place from their real position — Gaia will be able to see these effects and quantify the 'lensing' effect.

"Были когда-то и мы рысаками!!!"

Salo

http://forum.nasaspaceflight.com/index.php?topic=19838.msg1077271#msg1077271
Цитироватьjebbo пишет:
From @ESAGaia on Twitter:

"Today Gaia passed the Flight Acceptance Review successfully. Launch slot 17 November - 5 December 2013 agreed."
"Были когда-то и мы рысаками!!!"

Salo

http://www.arianespace.com/news-feature-story/2013/7-23-2013.asp
ЦитироватьThree Soyuz launchers are at the Spaceport for Arianespace's upcoming medium-lift missions from French Guiana

July 23, 2013

Two more Soyuz launchers have now arrived in French Guiana, joining a previously-delivered vehicle that is being readied for Arianespace's next Spaceport mission with the medium-lift workhorse.

The latest pair was brought by the MN Colibri – which is one of two roll-on/roll-off (RO/RO) ships used to transport the Soyuz, Ariane 5 and Vega members of Arianespace's launcher family from Europe to the company's South America operating base.

After docking at Pariacabo Port adjacent to the city of Kourou on Friday, July 19, the unloading began process for these two Russian-built vehicles, initiating a multi-day transfer process by road to the nearby Spaceport – which will be completed this week.

The MN Colibri's large enclosed RO/RO main deck, along with the external storage area on its upper deck, enable two complete Soyuz vehicles to be carried on transatlantic voyages from St. Petersburg, Russia to Kourou, according to Patrick Legris, who is part of Arianespace's logistics team at the Spaceport.

This latest delivery included all components for the two newly-delivered launchers: their first, second and third stages; the Fregat upper stage; payload fairing; and elements of the vehicles' propellant load.

The voyage was under the command of Capt. Anthony Charon, who works for the Compagnie Maritime Nantaise - MN, which operates the MN Colibri and its MN Toucan sister ship for Arianespace.

Charon said the 5,217-naut. mi. trip from St. Petersburg to Kourou took 14.5 days at the ship's operating speed of 15 kts., with the journey performed in excellent summer weather conditions.

The MN Colibri is the primary vessel used by Compagnie Maritime Nantaise - MN for launcher transportation duties on behalf of Arianespace, with the MN Toucan sister ship also available.  MN Colibri is the latest-built of the two, and incorporates certain updates based on the MN Toucan's operating experience for Arianespace, including the capability of stacking containers up to three high on the exterior upper deck.


The MN Colibri is docked at Pariacabo Port after its Atlantic crossing with two Soyuz launchers. Visible on the ship's upper deck external storage area are containers with the Russian-built vehicles' payload fairings.


Capt. Anthony Charon operates the MN Colibri's radar as the roll-on/roll-off ship is prepared for departure from Pariacabo Port after delivering two Soyuz launchers.


Containers with launcher stages for the two newly-delivered Soyuz vehicles await their transfer from Pariacabo Port to the Spaceport. These stages were carried in the MN Colibri's roll-on/roll-off main deck during the voyage from St. Petersburg, Russia to Kourou in French Guiana.
"Были когда-то и мы рысаками!!!"

Salo

"Были когда-то и мы рысаками!!!"

Salo

"Были когда-то и мы рысаками!!!"

Salo

http://www.esa.int/Our_Activities/Space_Science/Gaia/Gaia_has_arrived_in_French_Guiana
ЦитироватьGaia has arrived in French Guiana


Antonov plane at Toulouse airport during Gaia loading

23 August 2013

ESA's billion-star surveyor, Gaia, departed yesterday evening fr om Toulouse and arrived early this morning in French Guiana. Gaia will be launched later this year from Europe's Spaceport in Kourou on a five-year mission to map the stars of the Milky Way with unprecedented precision.

Built by Astrium in Toulouse, the Gaia spacecraft took off on board an Antonov 124 heavy-lift aircraft at 20.00 yesterday from Toulouse airport with the destination of Cayenne, the capital of French Guiana. The spacecraft will now be transported by truck to Europe's Spaceport in Kourou, 64 km from Cayenne.

"This is a very exciting day for the Gaia mission and all the teams involved, who have worked for years to get to wh ere we are today," says Giuseppe Sarri, ESA's Gaia project manager. "Arriving in Kourou and starting the launch campaign is a great achievement."

Gaia's main goal is to create a highly accurate 3D map of our galaxy, the Milky Way, by repeatedly observing a billion stars to determine their precise positions in space and their motions through it.


Placing the Gaia container onto the access ramp

A billion stars is roughly 1% of all the stars spread across the Milky Way, providing a representative sample from which the properties of the whole galaxy can be measured. Gaia will measure these stars from an orbit around the Sun, near a location known as the L2 Lagrangian point, some 1.5 million km beyond Earth's orbit.

Other measurements will assess the vital physical properties of each star, including its temperature, luminosity and composition.

The resulting census will allow astronomers to determine the origin and the evolution of our galaxy.

Gaia will also uncover tens of thousands of previously unseen objects, including asteroids in our Solar System, planets around nearby stars, and exploding stars – supernovae – in other galaxies.

Sarri, who also flew on the Antonov aircraft with Gaia, said that the flight from Europe to South America went smoothly. "We are now looking forward to the coming weeks of final preparation, which we will undertake with the same care and determination that the teams have shown so far when building the spacecraft."

On 28 August, a second Antonov 124 aircraft will carry Gaia's sunshield and most of the ground support equipment from Toulouse to Cayenne. At that point, all the spacecraft parts and equipment will have arrived in French Guiana, leading towards the launch later this year.
"Были когда-то и мы рысаками!!!"

PIN

Рекомендую блог http://blogs.esa.int/gaia/
Он менее формален и более содержателен :)

Salo

http://www.arianespace.com/news-mission-update/2013/1088.asp
ЦитироватьArianespace to "reach for the stars" with its Soyuz launch of Europe's Gaia space surveyor spacecraft
 

Shown in its protective shipping container, Europe's Gaia is unloaded fr om the cargo jetliner that transported this advanced "star-mapper" spacecraft from Toulouse, France – wh ere it was built by Astrium – to French Guiana.

 August 23, 2013 – Soyuz Flight VS07
Europe's Gaia "star-mapper" has arrived in French Guiana for an Arianespace Soyuz launch later this year on a mission to chart the locations and motions of a billion stars, while also opening opportunities in discovering new celestial objects in the hundreds of thousands.
 Gaia was delivered today aboard a chartered Antonov An-124 cargo jetliner at Félix Eboué International Airport near the capital city of Cayenne – clearing the way for its transfer via road to the Spaceport.
With a liftoff mass of 2,030 kg. – which includes the spacecraft's two optical telescopes, three science instruments, as well as a 10-meter deployable "skirt" as a sunshield and a power generator – Gaia will observe one billion stars approximately 70 times each over five years.
 
A truly impressive space charting mission
Many aspects of this mission – organized by the European Space Agency – are impressive. The spacecraft carries one of the largest digital cameras to be placed in space (with nearly one billion pixels), and is designed to detect celestial objects that are a million times fainter than the unaided human eye can see.
Built by Astrium at its Toulouse, France facility, Gaia will be operated by the European Space Agency to provide a representative sample from which the properties of the entire galaxy can be measured, ultimately allowing astronomers to determine its origin and evolution.
Gaia's two optical telescopes will determine star locations and velocities, splitting their light into a spectrum for analysis. The spacecraft will operate from an orbit around the Sun, at the L2 Lagrangian point located some 1.5 million kilometers beyond Earth's orbit.
 
Discoveries numbering in the hundreds of thousands also anticipated
During its operation, Gaia also is expected to find hundreds of thousands of new celestial objects – including asteroids, comets, extra-solar planets, brown dwarf "failed stars," supernovae and quasars.
When completed, the mission's data archive should exceed 1 petabyte (1 million gigabytes), which is equivalent to about 200,000 DVDs worth of data.
Gaia arrived today in French Guiana with a portion of its ground support equipment. A second air cargo flight later this month is to bring Gaia's sunshield and the remaining ground support equipment.
 
A mission follow-up to Hipparcos, also launched by Arianespace
The star-mapper has its roots in the European Space Agency's Hipparcos space astrometry platform, lofted by Arianespace on an Ariane-series vehicle in 1989. The Soyuz mission with Gaia is designated VS07 in Arianespace's launcher family numbering system, representing this medium-lift workhorse's seventh flight from French Guiana.
 It will follow two other Arianespace launches currently in preparation at the Spaceport: Flight VA215, scheduled for August 29 with an Ariane 5 to orbit the EUTELSAT 25B/Es'hail 1 and GSAT-7 relay satellites; and VS06, targeted in late September with a Soyuz to deploy four connectivity spacecraft for O3b Networks.
"Были когда-то и мы рысаками!!!"

Bauer

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