Watch the full replay of the launch coverage of ESA’s billion-star surveyor Gaia. Liftoff occurred at 09:12UT/10:12CET on 19 December and the successful deployment of Gaia’s sunshield was confirmed approximately 90 minutes later. Gaia is now on its way to L2, where it will study the characteristics of 1 billion stars to create the most precise 3D map of our home galaxy, the Milky Way.
Credt: ESA / CNES / Arianespace
Watch a replay of ESA’s billion-star surveyor Gaia lift off at 09:12UT/10:12CET on 19 December
Credits: ESA / CNES / Arianespace
Animation showing Gaia launch and journey to its operating orbit. The animation begins by visualising the launch from Europe’s Spaceport in Kourou, French Guiana, on a Soyuz-STB/Fregat-MT vehicle. The rocket’s four boosters are jettisoned 118 seconds after launch, and the spacecraft fairing is jettisoned after 220 seconds. Following two burns, the Fregat upper stage separates from Gaia 42 minutes after launch. The separation activates an automatic sequence onboard Gaia, including switching on the spacecraft’s transmitters, pressurisation of the propulsion system, initial attitude acquisition and deployment of the sunshield. By then Gaia will be on its transfer orbit from Earth towards L2, a virtual point in space some 1.5 million kilometres ‘behind’ Earth as seen from the Sun. Gaia will take about a month to cruise and manoeuvre into a ‘Lissajous’ orbit around L2. The size of the orbit is typically 340 000 x 90 000 km and takes 180 days. There, Gaia will spin slowly in order to make systematic repeated observations of stars covering the whole sky with its two telescopes. Over its five-year mission, Gaia will monitor the positions, motions, temperatures, luminosities and compositions of a billion stars.
Credit: ESA–C. Carreau/ATG medialab
ESA’s Gaia mission will produce an unprecedented 3D map of our Galaxy by mapping, with exquisite precision, the position and motion of a billion stars. The key to this is the billion-pixel camera at the heart of its dual telescope. This animation illustrates how the camera works.
See http://sci.esa.int/gaia/53281-inside-gaias-billion-pixel-camera/ for a more detailed description.
Credits: ESA
Gaia is ESA’s billion-star surveyor, designed to provide a precise 3D map of our Milky Way galaxy in order to understand its composition, formation and evolution.
This virtual journey shows the different components that make up our home galaxy, the Milky Way, which contains about a hundred billion stars.
It starts at the black hole at the centre of the Milky Way and with the stars that orbit around it, before zooming out through the central Galactic Bulge, which hosts about ten billion stars.
The journey continues through a younger population of stars in the stellar disc, home to most of the Milky Way’s stars, and which is embedded in a slightly larger gaseous disc. Stars in the disc are arranged in a spiral arm pattern and orbit the centre of the Galaxy.
The discs and bulge are embedded in the stellar halo, a spherical structure that consists of a large number of globular clusters — the oldest population of stars in the Galaxy — as well as many isolated stars. An even larger halo of invisible dark matter is inferred by its gravitational effect on the motions of stars in the Galaxy.
Looking at a face-on view of the Galaxy we see the position of our Sun, located at a distance of about 26 000 light-years from the Galactic Centre.
Finally, the extent of the stellar survey conducted by ESA’s Hipparcos mission is shown, which surveyed more than 100 000 stars up to 300 light-years away from the Sun. In comparison, ESA’s Gaia survey will study one billion stars out to 30 000 light-years away.
Our Galaxy the Milky Way is made up of a hundred billion stars. To truly understand its evolution we need to know exactly where we stand in this mass of constantly moving and changing celestial objects. To do this, astrometry, the science of measuring the position, distance and movement of stars around us, is just about to take a giant leap forward with the launch of ESA’s new space telescope, Gaia. Gaia will make it possible to measure a billion stars of our Milky Way.
It has spawned a host of songs from crooners to alternative rock bands. One of the best loved chocolate bars in the United Kingdom is named after it. Yet how much to we really know about the Milky Way and just how important is it?
We could be close to many answers about the galaxy thanks to a new satellite named Gaia, being launched by the European Space Agency.
“One fundamental step to understand our universe is to understand our closer universe, which is the galaxy,” explained Guiseppe Sarri who is the project manager of ESA’s Gaia project.
Gaia will scan the sky with powerful new eyes, mapping the Milky Way in unprecedented detail. It will help produce a detailed 3D image of the galaxy, something which has never been done before.
Olhando para o céu durante a noite é possível ver milhares de estrelas. Mas muito para além das visíveis existem milhões de outras escondidas na escuridão. Mais fracas, mais distantes, e profundamente misteriosas.
Podemos estar perto de as descobrir graças a um novo satélite denominado Gaia, que está a ser lançado pela Agência Espacial Europeia.
“Um passo fundamental para compreender o universo é entender o nosso universo mais próximo, a galáxia”, explicou Guiseppe Sarri, gestor do projeto Gaia da Agência Espacial Europeia.
O Gaia vai conseguir ver o céu com uns poderosos novos olhos e criar um mapa detalhado da galáxia em 3D. Algo nunca antes visto na astronomia.
Os astrónomos estão entusiasmados já que o satélite promete uma revolução. Vai observar, mapear e medir mil milhões de estrelas no total.
Para isso o satélite vai transportar a maior câmera digital que alguma vez voou para o espaço. Como Guiseppe Sarri salientou: “Estamos a falar de estrelas que são 400 mil vezes mais fracas do que as que podemos ver a olho nu.”
O grande número de dados recolhidos na missão deve ajudar os astrónomos a resolver alguns dos maiores quebra-cabeças no universo. Tais como a forma exata da nossa galáxia e os mistérios da matéria negra – a força oculta que molda o universo. O mapa da Via Láctea do satélite Gaia vai deixar o universo um pouco menos misterioso, mas nem por isso menos belo.
Les milliards d’étoiles de notre Voie lactée forment un labyrinthe dont nous avons du mal à appréhender l’étendue. Pour faire progresser les connaissances sur notre galaxie, l’Agence spatiale européenne mène la mission Gaia, du nom d’un satellite capable de scanner le ciel avec une précision extraordinaire, au moins mille fois supérieure à celle des observations depuis le sol.
L’engin construit par Astrium à Toulouse et lancé depuis Kourou en Guyane française va réaliser une première en astronomie en établissant une carte 3D détaillée de la Voie lactée : il calculera la position relative, la trajectoire et la vitesse d’un milliard d’étoiles. Ce qui correspond à 1% de l’ensemble des étoiles peuplant notre galaxie.
Pour l’aider dans ses observations, Gaia dispose de la plus grande caméra numérique jamais conçue pour une mission spatiale et comme point de référence, du plus grand téléscope de l’observatoire du Pic du Midi dans les Pyrénées.
Grâce à cette mission, les astronomes espèrent résoudre de grandes énigmes, notamment établir avec exactitude, la structure en spirale de la Voie lactée et trouver la trace de la matière noire, cette force invisible qui façonne notre univers.
Time-lapse sequences from the deployment test of the Gaia Deployable Sunshield Assembly (DSA) on 10 October 2013, in the cleanroom at Europe’s spaceport in Kourou.
Since the DSA will operate in microgravity, it is not designed to support its own weight in the one-g environment at Earth’s surface. Therefore, during deployment testing on the ground, the DSA panels are attached to a system of support cables and counterweights that bears their weight, preventing damage and providing a realistic test environment.
Once in space, the sunshield has two purposes: to shade Gaia’s sensitive telescopes and cameras, and to provide power to operate the spacecraft. Gaia will always point away from the Sun, so the underside of the skirt is partially covered with solar panels to generate electricity.
Credit: ESA
Gaia Deployable Sunshield Assembly (DSA) integrated onto the spacecraft and undergoing deployment testing at Astrium Toulouse. Since the DSA will operate in microgravity, it is not designed to support its own weight in the one-g environment at Earth’s surface. During deployment testing, the DSA panels are attached to a system of support cables and counterweights that bears their weight, preventing damage and providing a realistic test environment. The support system is clearly visible in the video.
As the DSA deploys, the flight model thermal tent comes into view and the mechanically representative dummy payload can be seen through the aperture in the tent. Towards the end of the deployment sequence, the flight model service module comes into view.
This test demonstrated correctness of alignment following integration, confirmed the deployment functionality and verified the flatness of the deployed DSA.
The video shows an edited, time-lapse sequence from the deployment of the DSA during a test campaign; the entire deployment sequence takes about 20 minutes.