Polar Satellite Launch Vehicle on the launchpad

EOS-6 (Oceansat-3) | PSLV

Lift Off Time
(Subject to change)
NET 2022
Mission Name
Oceansat-3 / Earth Observation Satellite 6, C53
Launch Provider
(What rocket company is launching it?)
Indian Space Research Organization (ISRO)
Customer
(Who’s paying for this?)
ISRO
Rocket
Polar Satellite Launch Vehicle (PSLV)
Launch Location
First Launch Pad, Satish Dhawan Space Centre (SDSC), India
Payload mass
960 kg
Where is the satellite going?
Sun-syncronous orbit (SSO), 723 km
Will they be attempting to recover the first stage?
No, this is not a capability of PSLV
Where will the first stage land?
It will crash into the Indian Ocean
Will they be attempting to recover the fairings?
No, this is not a capability of PSLV
Are these fairings new?
Yes
How’s the weather looking?
N/A
This will be the:
– 3rd flight of the OceanSat programme
– 13th flight of a PSLV rocket
– 79th lunch from the Satish Dhawan Space Centre
– 5th orbital launch attempt for 2022
Where to watch
If available, an official livestream will be listed here

What Does All This Mean?

India is launching OceanSat-3, the third in its set of ocean observation satellites, to a Sun-synchronous orbit atop a Polar Satellite Launch Vehicle (PSLV) rocket. The flight designation is C53.

What Is OceanSat-3?

OceanSat-3 is a multi-sensor ocean observation satellite, expected to operate until at least 2027. The following instruments and/or notable devices onboard are:

  • OSCAT – OceanSat Scatterometer
  • OCM – Ocean Color Monitor
  • SSTM – Sea Surface Temperature Monitor
  • A-DCS – Advanced Data Collection System

OSCAT is an instrument for measuring wind speeds and vectors at sea level. This is a newly developed instrument, operating in the Ku-band (13.515 GHz). It has two conical scanning beams, providing four views of each location from different angles. The instrument has a resolution that ranges between 25 km or 50 km, depending on conditions.

OCM is an instrument for measuring ocean color and aerosols. It is an evolution of the previous OCM instruments already flown on OceanSats 1 and 2. The instrument operates in visible and near infra-red portions of the electromagnetic spectrum, using 13 narrow-bandwidth channels. It scans using a “pushbroom” technique, providing 6000 pixels per line. The resolution of the instrument is 360 m or 1080 m, depending on conditions.

SSTM, the sea surface temperature monitor instrument, works alongside OCM. It has a 2-channel radiometer which makes measurements at both 11 and 12 μm wavelengths. This can resolve down to 0.15 K (0.15 °C / 0.27 °F) at a mean temperature of 300 K (~27 °C / ~80 °F) on both wavelengths.

The Advanced Data Collection System (also known as “Argo-3”) is not a measuring instrument, but is a transponder for exchange of data messages from onboard data collection platforms. It also provides location data about the satellite. It operates at a carrier frequency of 401.65 MHz with a bandwidth of 110 kHz. This provides a data rate between 400 to 4800 bps, depending on conditions.

What Is The PSLV?

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

  • PSLV-G
  • PSLV-CA
  • PSLV-DL
  • PSLV-QL
  • PSLV-XL

This flight is a PSLV-CA (“core alone”) flight, meaning that it does not feature any strap-on side boosters. In the absence of any strap-on boosters, the PSLV is a four stage rocket, using a variety of propellants.

India's launch vehicle family
India’s launch vehicle family (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 oxidiser. 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 2 m wide. It uses HTPB solid propellant, similar to the first stage, and features an S-7 engine. This stage runs for 83 seconds burn time, and the motor has an efficiency of 295 seconds ISP. Maximum thrust on this stage is 240 kN.

Stage Four (PS4)

The last stage is 3 m tall, and only 1.3 m wide. This is a liquid-fuelled stage, using monomethylhydrazine (MMH) for fuel and mixed oxides of nitrogen (MON) for oxidiser. The stage has two PS-4 engines, each of which produce 6.6 kN of thrust. The stage runs for 525 seconds of burn time, and has an efficiency of 308 seconds ISP.

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