Nanosats cannot peer as closely at the Earth or carry out as many experiments as big satellites.
微型卫星不能像大型卫星一样把地球看得那么仔细，也不能像大型卫星一样进行那么多实验。
2
One worry is that constellations of nanosats will mean a big increase in space junk; but, operating in low-Earth orbit, they burn up on re-entry after a year or so.