Space

Gaia launch delayed over dicey components

Gaia launch delayed over dicey...
Gaia mapping the stars of the Milky Way (Photo: ESA/ATG medialab; background image: ESO/S. Brunier)
Gaia mapping the stars of the Milky Way (Photo: ESA/ATG medialab; background image: ESO/S. Brunier)
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Transparent rendering of Gaia's service module, showing the troublesome X-band transponders at upper right (Photo: ESA)
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Transparent rendering of Gaia's service module, showing the troublesome X-band transponders at upper right (Photo: ESA)
Gaia mapping the stars of the Milky Way (Photo: ESA/ATG medialab; background image: ESO/S. Brunier)
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Gaia mapping the stars of the Milky Way (Photo: ESA/ATG medialab; background image: ESO/S. Brunier)
Exploded view of the Gaia spacecraft, showing the troublesome transponders near the bottom (Photo: EADS Astrium)
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Exploded view of the Gaia spacecraft, showing the troublesome transponders near the bottom (Photo: EADS Astrium)
Gaia's billion-pixel focal plane sensor (Photo: Astrium)
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Gaia's billion-pixel focal plane sensor (Photo: Astrium)
Layout of Gaia's billion-pixel focal plane sensor (Photo: ESA - Alexander Short)
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Layout of Gaia's billion-pixel focal plane sensor (Photo: ESA - Alexander Short)
Gaia's phased-array antenna and communications module (Photo: ESA)
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Gaia's phased-array antenna and communications module (Photo: ESA)

The Gaia mission to map a billion stars in the Milky Way has been delayed for about two months by the European Space Agency (ESA). X-band transponders used in other satellites have begun to fail, so the ESA has decided to replace those modules prior to launching. The likely blastoff date will be in late December of this year.

The Gaia mission is intended to map the position and velocity of a billion stars in the Milky Way to support ongoing studies on galactic dynamics. The main instrument for this mapping is a gigapixel camera, by far the most complex ever launched into space. The Gaia satellite will orbit near the L2 point positioned about 1.5 million kilometers behind Earth.

Gaia's phased-array antenna and communications module (Photo: ESA)
Gaia's phased-array antenna and communications module (Photo: ESA)

Gaia will produce a three-dimensional map of our galaxy. The map will be missing most of the Milky Way's stars (only including one billion of a total of some 400 billion), but this will cover our galactic region in considerable detail, and will provide much needed information about more distant and dust-obscured regions. The positions will be solid to about 24 microarcseconds, which is the width of a human hair at a distance of 1,000 km (621 mi).

Transparent rendering of Gaia's service module, showing the troublesome X-band transponders at upper right (Photo: ESA)
Transparent rendering of Gaia's service module, showing the troublesome X-band transponders at upper right (Photo: ESA)

As a "free" side result, Gaia is expected to find hundreds of thousands of asteroids and comets in the solar system, perhaps 7,000 exoplanets, 20,000 supernovae, and hundreds of thousands of quasars. Clearly, the analysis of Gaia's petabyte (one million gigabytes) of data will continue long after its five-year mission is complete.

Source: ESA

2 comments
Don Duncan
Mapping our galaxy should have been done long ago. Especially looking for earth-like exoplanets, but first things first, e.g., solar systems. If we can't go there, we can send a communication or focus in on a likely transmitter. That is much more valuable than going to the moon or mars. Opening up communication with another intelligent species may accelerate our technological status, and theirs. Exchanging ideas is a valuable learning tool, perhaps more so than manned space flight, which is learning the hard way. Only a statist mentality would be against it.
nehopsa
...well, provided the little green men are there waiting to give you technological boost (and would not misuse your tracking beam for invasion - if your logic is to be followed). The fact is that their existence is...highly unlikely. ..to the infinitesimal fraction. On the other hand, with Mars you at least have a second planed for survival, after this one goes bang.....and the chance of that happening equals one - it is absolutely certain, only the time horizon in which it would happen is variable, per S. Hawking thinking anyway.