There is plenty of bandwidth to achieve more than 1 Gbps of throughput from a 3-U cubesat (see Planet with their latest X-band comms-system [1], which results i

There is plenty of bandwidth to achieve more than 1 Gbps of throughput from a 3-U cubesat (see Planet with their latest X-band comms-system [1], which results in more than 50 GB per pass). If you really need more than that, new free space optical communications systems under-development will bring multi-Gbps to small-sats [2]. For me, the real problem with nanosats is that they generate barely no power and they are really volume-constrained compared to the bigger birds (so you cannot have high-resolution sensors, and cannot fit in there a good optical-comms system, you need to be mindful of your power consumption all time during the mission...). Finally, note that nowadays Planet downloads 10 TB/day, and they could go up to 40 TB/day once they upgrade their fleet with the latest X-band antenna, which is comparable to the 80 TB/day that DigitalGlobe generates. [1] https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=4405&context=smallsat https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=4... [2] https://www.tesat.de/images/tesat/products/TOSIRIS_Data-Sheet.pdf https://www.tesat.de/images/tesat/products/TOSIRIS_Data-Shee...