ISRO's SDX02 Faces Broad Reentry Window as Orbit Drops

Space-Track has issued a tracking and impact prediction for ISRO's 180 kg SDX02, also called SPADEX-B, placing nominal reentry at 12:10 UTC on October 13, 2026, with a 45-day uncertainty window. The satellite is in a near-circular orbit at roughly 239 km mean altitude and has been losing altitude rapidly, including about 6.0 km per day over the last two days. Because the window remains so wide, the actual reentry point could lie anywhere along its ground track between 55° north and 55° south.

SDX02 belongs to ISRO's SpaDeX mission, which demonstrated two spacecraft meeting and docking autonomously. It flew with SDX01 on PSLV-C60, lifting off from Sriharikota on 30 December 2024. The two docked on 16 January 2025, then separated so each could run its payload. SDX02 carries RadMon, a radiation-dose instrument, and was intended to operate for two years.

The satellite is built on the SPADEX microsatellite bus, SSB-2 variant. Its body is box-like, with two unfolding solar panels spanning 2.5 m, batteries, and three-axis stabilization. Launch mass was 220 kg; dry mass is 180 kg. It is described as aluminium and composite construction.