PSLV-C3 was the third operational launch and overall sixth mission of the PSLV program. This launch was also the forty-sixth launch by Indian Space Research Organisation since its first mission on 1 January 1962. The vehicle carried three satellites which were deployed in the Sun-synchronous Low Earth orbit. The vehicle carried Technology Experiment Satellite (Indian experimental Earth observation satellite), BIRD (German Earth observation satellite) and PROBA (experimental satellite from Belgium). This was India's and ISRO's second commercial spaceflight. PSLV-C3 was launched at 10:23 a.m. IST on 22 October 2001 from Satish Dhawan Space Centre (then called "Sriharikota Range").

Mission highlights The mission involved placing Technology Experiment Satellite (TES) and Bispectral and Infrared Remote Detection (BIRD) in a 568 km circular orbit. It would then place the PRoject for On Board Autonomy (PROBA) satellite in an 568 km x 638 km elliptical orbit. This demonstrated ISRO capability to launch multiple satellites in multiple orbits. It also earned ISRO $1 million for each satellite.

Mission parameters Mass: Total liftoff weight: Payload weight: Overall height: Propellant: First stage: Solid HTPB based (138.0 + 54 tonnes) Second stage: Liquid UDMH + (40 tonnes) Third stage: Solid HTPB based (7 tonnes) Fourth stage: Liquid MMH + MON (2.0 tonnes) Engine: First stage: S139 Second stage: Vikas Third stage: Fourth stage: 2 x PS-4 Thrust: First stage: 4,430 + 677 x 6 kN Second stage: 724 kN Third stage: 324 kN Fourth stage: 7.4 x 2 kN Altitude: Maximum velocity: (recorded at time of fourth stage ignition) Duration: 1,658 seconds

Payload PSLV-C3 carried and deployed total three satellites. Technology Experiment Satellite (TES) was the main payload and BIRD and PROBA were two auxiliary payloads that were mounted on PSLV-C3. In the flight sequence, TES was injected first, followed by BIRD and then PROBA.

Country Name Nos Mass Type Objective India TES 1 1,108 kg Satellite Experimental Earth observation satellite Belgium BIRD 1 94 kg Microsatellite Remote sensing technology demonstration Germany PROBA 1 92 kg Microsatellite Earth observation technology demonstration

Launch and planned flight profile

PSLV-C3 was launched at 10:23 a.m. IST on 22 October 2001 from Satish Dhawan Space Centre (then called "Sriharikota Launching Range"). The mission was planned with pre-flight prediction of covering overall distance of . The total flight time was 1658 seconds as PROBA was to be launched into an elliptical orbit after TES and BIRD were launched into a circular orbit. The orbit raise was done using the yaw RCS thrusters in off-modulated mode.

Following was the planned flight profile.

Stage Time(seconds) Altitude (kilometer) Velocity(meter/sec) Event Remarks First stage T+0 0.02 452 First stage ignition Lift-off T+1.24 Ignition of 4 ground-lit strap-on motors T+25.04 2.515 551 Ignition of 2 air-lit strap-on motors T+68.04 23.472 1,155 Separation of 4 ground-lit strap-on motors T+90.04 40.061 1,644 Separation of 2 air-lit strap-on motors T+112.73 67.601 2,028 First stage separation Second stage T+112.93 67.828 2,027 Second stage ignition T+156.73 115.604 2,284 Heat shield separation T+278.81 236.272 4,099 Second stage separation Third stage T+280.01 237.433 4,097 Third stage ignition T+498.33 455.487 6,086 Third stage separation Fourth stage T+520.60 460.818 6,065 Fourth stage ignition T+914.92 571.247 7,575 Fourth stage thrust cut-off T+971.92 572.080 TES separation T+1,011.92 572.709 BIRD separation T+1,091.92 574.064 PROBA orbit raise start T+1,552.50 585.018 7,593 PROBA orbit raise stop T+1,602.50 586.688 7,592 PROBA orbit separation Mission over

Fourth Stage Break-up event The fourth stage of the PSLV had undergone a break-up event on 19 December 2001, likely caused by an explosion. After the explosion of PSLV-C3, ISRO carried out passivation of the upper stages of the PSLV, from the PSLV-C4 mission onwards. As per ISRO, this event generated 386 debris objects, of which 76 were in orbit in 2021, falling to 41 by 2025.

See also Indian Space Research Organisation Polar Satellite Launch Vehicle

References