Time for a Pint for the lads/lasses then ... :)
NASA reports that the last data from the New Horizons flyby of Pluto has finally been received on Earth. On July 14 last year, the spacecraft shot past Pluto and amassed over 50GB of data about the mini-planet. Getting it back to Earth was the tricky part – the massive distances involved mean that the data flow was limited to …
... and amassed over 50GB of data about the mini-planet. Getting it back to Earth was the tricky part – the massive distances involved mean that the data flow was limited to one kilobit per second
So, that's 1KiB every 8 seconds?
... 7K a minute?
... 420K an hour?
... 10080K a day? (So 9MiB a day)
50GiB == 51200MiB
51200/9 = 5688.8 days == 15.5 years?
So, are the numbers wrong? My maths? Or do they just pick and choose what to retrieve?? (Even if it's 1KiB/Sec that's still nearly 2 years, has it really been that long since it got there???)
50GB is a significant amount of data, even in today's terms, but thinking back to when this mission was conceived that sort of data volume would be almost unimaginable.
NASA obviously forecast that data storage would become bigger/faster/cheaper down here on Earth by the time the data started to be sent back, but presumably they needed fairly hefty storage/buffering capacity at the point of capture. Quite a feat given the tech at the time the craft was built.
Having done a little reading around it seems that the spacecraft has 2 transmitters and both can be used simultaneously if they shutdown other equipment on board. That nearly doubles the data rate to 2Kb/s but that still doesn't explain the discrepancy. I also see that the image data can be compressed by a considerable factor so this is probably more likely to be the explanation - the 50GB figure is going to be the total data size before compression.
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