Solar Cycle 25 Peak & The 5-Year Deorbit Rule: Why 500–550 km SSO PocketQubes Pass Without Propulsion
Because a 1P PocketQube has twice the area-to-mass ratio of a 1U CubeSat, natural atmospheric drag clears 1P missions from 550 km within 2.5–4.2 years under moderate-to-high solar activity.
Under the FCC 5-year post-mission disposal rule (effective September 2024) and ESA’s Zero Debris Charter, low-Earth-orbit spacecraft must re-enter within five years of mission completion.
For 1U–3U CubeSats with ballistic parameters around 0.015 m²/kg, rideshare drops above 525 km frequently require drag sails or propulsion if launched near solar minimum.
By contrast, a 250 g 1P PocketQube (ballistic parameter ≈0.033 m²/kg) experiences roughly twice the deceleration, naturally complying with the 5-year ceiling up to ~560 km at moderate solar flux—as confirmed empirically by Grizu-263A (628 days from 525 km) and Delfi-PQ (~2 years from 525 km).