Lift Off Time
April 22, 2023 – 08:49 UTC | 14:19 IST
Mission Name
TeLEOS-2, an Earth-observation satellite 
Launch Provider
(What rocket company launched it?)
Indian Space Research Organization (ISRO)
(Who paid for this?)
ST Engineering
Polar Satellite Launch Vehicle (PSLV)
Launch Location
First Launch Pad, Satish Dhawan Space Centre, India
Payload mass
~757 kg
Where did the satellites go?
586 km Low-Earth Orbit (LEO), at an inclination of 10°
Did they attempt to recover the first stage?
No, this is not a capability of PSLV
Where did the first stage land?
It crashed into the Indian Ocean
Did they attempt to recover the fairings?
No, this is not a capability of PSLV
Were these fairings new?
This was the:
– 2nd satellite developed by ST Engineering to be launched by ISRO
– 10th Singaporean satellite to be launched by ISRO
– 57th flight of PSLV

– 16th mission of PSLV-CA
– 1st mission of PSLV of 2023
– 3rd mission of ISRO of 2023
– 62nd orbital launch attempt of 2023
Where to re-watch
Official replay

How Did It Go?

The Indian Space Research Organization’s Polar Satellite Launch Vehicle (PSLV) successfully launched the TeLEOS-2 mission from the First Launch Pad at Satish Dhawan Space Centre, Sriharikota, India. The rocket carried the TeLEOS-2 Earth-observation satellite as a primary payload and the LUMELITE-4 satellite as a secondary payload.

TeLEOS-2 Mission


The TeLEOS-2 is an Earth-observation satellite that belongs to Singapore and was built under a partnership between DSTA (representing the Government of Singapore) and ST Engineering. With a mass of 741 kg, the TeLEOS-2 satellite is designed to fulfill the satellite imaging needs of several departments within the government of Singapore. It features a Synthetic Aperture Radar (SAR) payload, which enables the satellite to capture images at a full-polarimetric resolution of one meter regardless of weather conditions or time of day. This is the second satellite developed by ST Engineering that was launched by ISRO.

The TeLEOS-2 satellite.
The payloads on the TeLEOS-2 mission. (Credit: ISRO)


Moreover, the TeLEOS-2 mission carried another Singaporean satellite, the LUMELITE-4, as a secondary payload. The LUMELITE-4 is a technology demonstration nano-satellite with a mass of 16 kg. It was built by the Institute for Infocomm Research (I2R) of A*STAR and the Satellite Technology and Research Centre (STAR) of the National University of Singapore.

The LUMELITE-4 is a 12U satellite created to showcase the High-Performance Space-borne VHF Data Exchange System (VDES) developed by I2R. By combining the VDES communication payload with STAR’s adaptable satellite bus platform, the satellite is intended to enhance Singapore’s e-navigation maritime safety.


Time (s)Events
-3RCT Ignition
0PS1 Ignition
109.86PS1 Separation
110.06PS2 Ignition
115.06CLG Initiation
183.96Heat Shield Separation
260.68PS2 Separation
261.88PS3 Ignition
586.68PS3 Separation
982.42PS4 Ignition
1114.04PS4 Engine Cut-off
1171.04TeLEOS-2 Separation
1221.04Lumelite-4 Separation
1354.04MON Passivation Start
1694.04MMH Passivation Start

What Is The PSLV?

India’s Polar Satellite Launch Vehicle comes in several variants. These are:

  • PSLV-G

This flight is a PSLV-CA flight, meaning that it used the core alone version that features no side boosters. Without these strap-on boosters, the PSLV is a four-stage rocket that uses a variety of propellants.

India's PSLV-CA launch vehicle.
India’s PSLV-CA launch vehicle. (Credit: ISRO)

Stage One (PS1)

The first stage is 20 m tall and 2.8 m wide. It uses hydroxyl-terminated polybutadiene (HTPB) propellant, using an S139 solid rocket motor. This stage has a 110-second burn time, with the motor featuring an efficiency of 137 seconds ISP (at sea level). It has a maximum thrust of 4800 kN.

Stage Two (PS2)

The second stage is 12.8 m tall, and 2.8 m wide. It uses unsymmetrical dimethylhydrazine (UDMH) as fuel and N2O4 as an oxidizer. The Vikas engine on this stage was developed by the Liquid Propulsions Systems Centre. The motor runs for a burn time of 133 seconds, with the engine having an efficiency of 293 seconds ISP.

PSLV rocket at launch, March 31, 2019.
PSLV rocket at launch, March 31, 2019. (Credit: ISRO)

Stage Three (PS3)

The third stage is 3.6 m tall, and two meters wide. It uses HTPB solid propellant, similar to the first stage, and features an S-7 engine. This stage runs for 83 seconds of burn time, and the motor has an efficiency of 295 seconds ISP. The maximum thrust on this stage is 240 kN.

Stage Four (PS4)

The last stage is three meters tall and only 1.3 m wide. This is a liquid-fueled stage, using monomethylhydrazine (MMH) as fuel and mixed oxides of nitrogen (MON) as the oxidizer. The stage has two PS-4 engines, each of which produces 6.6 kN of thrust. The stage runs for 525 seconds of burn time and has an efficiency of 308 seconds ISP.

Moreover, the TeLEOS-2 mission used the spent fourth stage as an orbital platform designated as the PSLV Orbital Experimental Module (POEM) to conduct in-orbit experiments. The POEM carried seven scientific payloads: ARIS-2, PiLOT, ARKA200, Starberry, DSOL, DSOD-3U, and DSOD-6U.

The POEM platform is powered by solar panels that can be found around the PS4 tank and a lithium-ion battery. It navigates using a magnetometer, four sun sensors, gyros, and NavIC. Moreover, the platform is equipped with dedicated control thrusters that use helium.

Rocket section adapted from Andy Law.

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