Re-entry
SRE-1 was traveling around the earth in a circular polar orbit at an altitude of 637 kilometers. In preparation for its reentry, SRE-1 was put into an elliptical orbit with a perigee of 485 kilometers and an apogee of 639 kilometers by issuing commands from the spacecraft control centre of ISTRAC at Bangalore on January 19, 2007. The critical de-boost operations were executed from SCC, Bangalore supported by a network of ground stations at Bangalore, Lucknow, Sriharikota, Mauritius, Biak in Indonesia, Saskatoon in Canada, Svalbard in Norway besides shipborne and airborne terminals.
On January 22, 2007, the re-orientation of SRE-1 capsule for de-boost operations commenced at 08:42 am IST. The de-boost started at 09:00 am with the firing of on-board rocket motors and the operations were completed at 09:10 am. At 09:17 am, SRE-1 capsule was reoriented for its re-entry into the dense atmosphere. The capsule made its re-entry at 09:37 am at an altitude of 100 kilometers with a velocity of 8 km/s (ca. 29,000 km/h). During its reentry, the capsule was protected from the intense heat by carbon phenolic ablative material and silica tiles on its outer surface.
By the time SRE-1 descended to an altitude of 5 km, aerodynamic braking had considerably reduced its velocity to 101 m/s (364 km/h). Pilot and drogue parachute deployments helped in further reducing its velocity to 47 m/s (169 km/h).
Read more about this topic: Space Capsule Recovery Experiment