Billion-dollar 'discovery machine' set for launch

Dec 17, 2013 by Veronique Martinache
Gaia mapping the stars of the milky way. Credit: ESA/ATG medialab; background: ESO/S. Brunier

Europe on Thursday will place a billion-dollar bet on a space telescope designed to provide the biggest and most detailed 3-D map of the Milky Way.

If all goes well, a Soyuz-STB-Fregat rocket will lift off from Kourou, French Guiana, hoisting the observatory Gaia on a five-year exploration that may sweep away notions of our place in the galaxy.

The most sophisticated ever built by Europe, the 740-million-euro ($1.02-billion) gadget goes by the unofficial epithet of "discovery machine".

"The list of Gaia's potential discoveries makes the mission unique in scope and scientific return," says the European Space Agency (ESA).

Gaia's primary goal is to carry out an "astronomical census", locating the position of a billion stars, or around one percent of all the stars in the Milky Way.

By repeating the observations as many as 70 times throughout its mission, the telescope can help astronomers calculate the distance, speed, direction and motion of these stars.

"Within two years from now we will have the first compendium of the sky," said Francois Mignard of France's Cote d'Azur Observatory.

Europe's last star-hunter, Hipparcos, was an almost legendary piece of equipment.

Launched in 1989 and in operations for nearly four years, it provided a high-accuracy fix on 118,000 stars, as well as less-precise fixes on two million stars—a databank that is hugely used by professional astronomers today.

Gaia, using a six-sided "optical bench" three metres (10 feet) across to snare glimmers of light, is 200 times more sensitive than Hipparcos in measuring the angles that, through triangulation, determine a star's position.

"If Hipparcos could measure the angle that corresponds to the height of an astronaut on the Moon, Gaia will be able to measure his thumbnail," ESA says on its website.

Gaia's secondary objectives are equally stunning. By monitoring the "wobble" in stellar light as a planet passes in front of a star, it can add to knowledge about worlds beyond the Solar System.

By some estimates, it could detect as many as 50,000 planets within a distance of 150 light years from the Sun, or 10 times more than have been observed since the first was spotted in 1995.

Rogue rocks and brown dwarves

Gaia will also be turning its eyes to our own Solar System, scouring its chill, dark fringes and the asteroid belt between Mars and Jupiter to help the search for any rocks that may one day threaten Earth.

Other potential bounty includes real-time observations of exploding stars, called supernovae, in distant galaxies and insights into strange "failed" stars, known as brown dwarves, that drift listlessly through interstellar space after failing to gain enough mass to ignite.

Gaia may provide a useful test of Einstein's theory of general relativity, which says that a star's position will appear to move slightly as a result of light from it that is deflected by a passing, massive object.

After launch, Gaia will take up position at the so-called Lagrange point L2, located 1.5 million kilometres (937,000 miles) from the Earth.

L2 is a position that gives it year-round observation of the cosmos without the view being disturbed by the Sun, Earth or Moon.

It is the go-to place for space observatories. L2 has been used by Europe's Herschel and Planck telescopes and is designated as the slot for NASA's eagerly-awaited James Webb Space Telescope (JWST).

To stay at L2, the spacecraft will have to perform tiny manoeuvres every month, scrutinised by a network of telescopes on Earth to ensure a hoped-for accuracy of 100 metres (yards).

One of the biggest challenges will be processing what Jean-Yves Le Gall, head of France's National Centre of Space Studies (CNES), calls "an absolute flood" of data.

Gaia will provide the equivalent of more than 30,000 CD-ROMs.

Sorting this stuff and turning it into useable data—galaxy maps and star catalogues—will take years.

Six centres have been set up around Europe to handle the deluge, including a supercomputer in Toulouse, southwestern France, capable of carrying out six thousand billion operations a second.

Explore further: Gaia secured inside fairing

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User comments : 9

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Egleton
2.3 / 5 (6) Dec 17, 2013
Not bad for an ape/pig hybrid.
Zephir_fan
Dec 17, 2013
This comment has been removed by a moderator.
axemaster
1 / 5 (1) Dec 17, 2013
So here's the thing I don't understand. Most of the cost of these telescopes is in development. So why do they only build and launch one of them? Couldn't they launch 5 of them and get 5 times the data for only a marginal increase in cost? Plus then they'd have a lot of redundancy, so they wouldn't have to panic when a flywheel goes nuts...
shavera
not rated yet Dec 17, 2013
There are not astronauts on it. Precision equipment costs a lot of time to develop. Then you need to protect that precision when you place it into space.

Second, each of these telescopes serves different purposes. This one is for doing precision angular measurement. But you could put up a microwave telescope to measure the CMB, an infrared telescope to measure dust and warm bodies, visible, UV, X-rays, etc. each for different purposes. Hubble was an example of something a bit more generic, and it got a lot of useful data, but we can get very great data by building telescopes with a purpose.

Then when we go build the next telescope of the same variety, we may borrow a lot of the design and parts of the last, but we probably have new questions to ask, or want more precision than the last model, so we have to upgrade things here and there.
davidivad
3 / 5 (2) Dec 17, 2013
to zepher fan;

the Russians are the only ones in the world who have come up with a time tested production savvy rocket.
IMP-9
5 / 5 (6) Dec 17, 2013
The major cost of a mission is not development. A full industrial study (which is a complete design of the mission) may cost tens of millions of euros but that is tiny in comparison to the overall mission. Flying 5 more instruments would hugely increase the cost, and what would you get? 5 redundant data sets, hardly worth the cost for slightly smaller errors. If a mission goes belly up it's better to take years replacing it than build 2 of every mission simply on cost.

Europe has a launch company Arianespace who are launching Gaia. It is a Russian Soyuz simply because that's Arianespace's medium launcher. Europe build Vega and Ariane 5, Vega is to small, Ariane 5 is very expensive and it's size is not required.
Zephir_fan
Dec 17, 2013
This comment has been removed by a moderator.
ACW
3 / 5 (2) Dec 17, 2013
We used to have a heavy-lift rocket (the Saturn 5), but nobody makes the parts and we lost the blueprints.
http://amyshirate...aturn-v/
davidivad
1 / 5 (2) Dec 17, 2013
The major cost of a mission is not development. A full industrial study (which is a complete design of the mission) may cost tens of millions of euros but that is tiny in comparison to the overall mission. Flying 5 more instruments would hugely increase the cost, and what would you get? 5 redundant data sets, hardly worth the cost for slightly smaller errors. If a mission goes belly up it's better to take years replacing it than build 2 of every mission simply on cost.

Europe has a launch company Arianespace who are launching Gaia. It is a Russian Soyuz simply because that's Arianespace's medium launcher. Europe build Vega and Ariane 5, Vega is to small, Ariane 5 is very expensive and it's size is not required.


like i said, nothing beats a soyuz.
antialias_physorg
5 / 5 (2) Dec 17, 2013
So why do they only build and launch one of them?

Because you're given a budget. If you plan for 5 of them to be built/launched that will eat into your ability to develop/build the best possible machine.

Science is prototypes. Always. Anything else is engineering.

Edit: Damn..IMP-9 beat me too it. Should have read all posts first ...
GSwift7
5 / 5 (1) Dec 18, 2013
including a supercomputer in Toulouse, southwestern France, capable of carrying out six thousand billion operations a second


That's almost good enough to get 100 frames per second on Call of Duty 4 with max graphics settings. lol

All kidding aside, the reasons given by other people here for not building multiple copies of each mission are great, but I would add another.

If you build 5 copies of the same thing, and then find out that the design was flawed, then you have 5 failures and no money to build something better. Remember the Space Shuttle program? Ceramic tiles, go figure.

In an observatory mission, like the one here, a large portion of the cost (as the story above hints at) is in the data processing. It requires its own supercomputer (in a special building with conditioned air, power backup, etc), and a full time staff, probably for more than 20 years.