SRE-1 – The Return to Earth

The de-boost operations of SRE-1 commenced at 08:42 am on January 22, 2007. 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 km with a velocity of 29,000 km per hour. By the time SRE-1 descended to an altitude of 5 km, aerodynamic breaking had considerably reduced its velocity to 363 km per hour. Pilot and drogue parachute deployments helped in further reducing its velocity to about 170 km per hour.

The main parachute was deployed at about 2 km altitude and finally SRE-1 splashed down in the Bay of Bengal with a velocity of about 43 km per hour at 09:46 am. The flotation system, which immediately got triggered, kept the capsule floating. Recovery operations were supported and carried out by the Indian Coast Guard and Indian Navy using ships, aircraft and helicopters.

 

 
Salient Features
    
 
Physical
    
 
Shape
:
Sphere-cone-flare
 
Overall size
:
Base diameter : 2.03 m
Height : 1.67 m
 
Mass at launch
:
555 kg
 
Thermal protection
:

Ablative Nose Cap
Re-usable Silica TPS
Low Density Ablatives
 
Navigation, Guidance
and Control
 
 
Processing
:
Mission Management Unit (MMU)
Inertial Measurement Unit (IMU)
Sun sensors, Magnetometer Sensors
 
Actuators
:
Magnetic Torquer/22N thrusters
 
Propulsion
:
22 N Bi-propellant thrusters (eight nos.)
  Power
:
Battery and body mounted solar panels
 
TTC
:
S-Band with Belt Array antenna
 
Deceleration system
:
Three stage parachute system
   
:
  
 
Experiments:
 
   
:
1. Growth of Ico Ga-Mg-Zn quasi crystal
   
:
2. Bio-mimetic synthesis of inorganic material
 
Launcher
:
PSLV-C7 with CARTOSAT-2, LAPAN-TUBSAT
and PEHUENSAT-1 as co-passengers
 
Orbit
:
635 km circular (polar orbit)
 
No. of days in orbit
:
12
 
Impact velocity
:
12 m/s
 
Recovery
:
140 km off Sriharikota in the Bay of Bengal
 
Recovery aids
:
Flotation system UHF Beacon and Sea Marker Dye
 
Recovery team
:
Indian Coast Guard assisted by Indian Navy