Isn't there a ton of space debris, ranging in size from mm to meters? A 1U cubesat is 10x10x11cm, and these satellites are listed as 10x10x2.8cm. What are the size bounds of the "danger zone" of items that are too small to spot reliably but still large enough to damage satellites? Would a 1cm³ / ~10 gram steel bolt be a problem? What about all of the chunks of debris created by previous space collisions and anti-satellite weapons?
Also, it seems like either (A) the satellites are big enough to track using the space surveillance network, negating the FCC's complaint, or (B) the satellites are too small to see reliably, meaning that it would be hard to pin any collision on these satellites. Perhaps there is a gray area where we can observe it, but not reliably.
I wonder how the FCC makes these decisions. The article mentioned that Swarm included passive radar reflectors, but that those will only help boost the radar cross-section for a small band of frequencies that are only used by a small fraction of the SSN. Ideally, our detection capability will improve over time and this will cease to be an issue. It would be a shame if no US company could ever launch a sub-1U satellite.
>Would a 1cm³ / ~10 gram steel bolt be a problem? What about all of the chunks of debris created by previous space collisions and anti-satellite weapons?
The satellites on this rocket were launched into a ~500km polar orbit, which means that they're moving at ~7.6 km/s. If they were to run into something at the same altitude in an equatorial orbit, they'd have a relative velocity of >10 km/s. That 10g bolt has as much energy as a sedan going at highway speeds.
Chunks of debris from previous satellites are absolutely an issue - the ISS cupola was visibly damaged when it was hit by a literal fleck of paint.
Considering the limits of battery storage (in terms of Wh per kg, and Wh per cubic cm) and triple-junction GaAs PV cells. I question how useful a 1/4U cubesat can really be, if it needs to have both TT&C/bus management computer, some sort of Rx/TX radio to serve a purpose, possibly a single orientation gyro, some form of cold gas thruster for maneuvering, etc.
Even with a 6U size cubesat you are very limited in terms of data rate throughput (in Mbps) you can achieve in bands above VHF/UHF. Simply due to the size limits of antenna you can fold down and the Shannon-Hartley limit.
I don't think they're too concerned with throughput. The idea was just some level of connectivity to retrieve basic information from areas that currently have none. The communication would literally be limited to what the satellite could store in onboard memory.
Also, it seems like either (A) the satellites are big enough to track using the space surveillance network, negating the FCC's complaint, or (B) the satellites are too small to see reliably, meaning that it would be hard to pin any collision on these satellites. Perhaps there is a gray area where we can observe it, but not reliably.
I wonder how the FCC makes these decisions. The article mentioned that Swarm included passive radar reflectors, but that those will only help boost the radar cross-section for a small band of frequencies that are only used by a small fraction of the SSN. Ideally, our detection capability will improve over time and this will cease to be an issue. It would be a shame if no US company could ever launch a sub-1U satellite.