We’ve come to love the fantastic and sublime images of space taken from such satellites as the Hubble, but the truth is that the technology that created those images is incredibly out of date. And while you can’t argue with the results, it has gotten to the point where the sensitivity, angle of view, and data collection rate just need to be moved up to 21st-century standards. The European Space Agency (ESA) is happy to bring space into the gigapixel era, and they’re packing a monster camera array onto their Gaia astrometry platform.
The mission of Gaia is accurate mapping of the entire Milky Way galaxy, and they plan to chart the positions of a billion stars about seventy times each over the next five years. The result will be (they hope) a more accurate and precise three-dimensional map of the galaxy. They’ll also pick up innumerable minor bodies (i.e. asteroid, planets, and so on) and will collect a ton of other useful miscellaneous space data.
The camera itself is actually over a hundred individual sensors put into an array — which makes sense, as a single gigapixel sensor would likely be far too small and pixel-dense to be of any use in this situation. The 102 sensors are 4.7×6.0cm each, and arranged in a large 1.0×0.5m field, and four more are used for quality checks.
The precision of the camera is pretty insane. It can resolve items of magnitude 15, which is 4000 times dimmer than what can be seen with the naked eye, down to 24 microarcseconds. To give you an idea of how powerful that is, if the Gaia array was on Earth, it could measure the thumbnails of a person standing on the moon. It will produce a huge amount of data, but its transmitter will be able to maintain a multi-megabit connection to its base station here on the ground even at a distance of 1.5 million kilometers.