Impact on the comet's surface occurred 14.5 hours after its descent manoeuvre; the final data packet from Rosetta was transmitted at 10:39:28.895 UTC (SCET) by the OSIRIS instrument and was received at the European Space Operations Centre in Darmstadt, Germany, at 11:19:36.541 UTC. The spacecraft's estimated speed at the time of impact was 3.2 km/h (2.0 mph; 89 cm/s), and its touchdown location, named Sais by the operations team after the Rosetta Stone's original temple home, is believed to be only 40 m (130 ft) off-target. The final image transmitted by the spacecraft of the comet was taken by its OSIRIS instrument at an altitude of 20 m (66 ft) about 10 seconds before impact, showing an area 0.96 m (3.1 ft) across. Rosetta's computer included commands to send it into safe mode upon detecting that it had hit the comet's surface, turning off its radio transmitter and rendering it inert in accordance with International Telecommunication Union rules.