[newpavlov]

I wonder if they could reduce the data size at rest by using specialized compressing techniques. Your probably could build an averaged "model" of the sky observed by the telescope (probably with account for stellar parallax and bright planets) and store only compressed diffs, not full images.

But I guess, since storage is relatively cheap, it's simply impractical to bother with such complexity.

[xhkkffbf]

There's quite a bit of black out there. That should compress easily.

[newpavlov]

The usual lossless image compression algorithms is the given. I am talking about compressing it further since the telescope observes the same (or largely overlapping) patches of the sky and the most significant signal is stars, which are more or less "constant". At the very least, they probably could use the lossless "animation" compression algorithms like APNG or FLIF for consequent images of the same sky patch.

[aragilar]

Look up fpack and funpack.