Cubesats at their typical altitudes have deorbit times ranging from 6 months to 20 years, with regulation (in the USA at least) mandating a deorbit within 25 ye

Cubesats at their typical altitudes have deorbit times ranging from 6 months to 20 years, with regulation (in the USA at least) mandating a deorbit within 25 years to receive a license. The fear of Kessler syndrome is much more relevant to launching large geostationary satellites that may break apart than for cubesats.