ISRO’s SSLV-D2 launch


    In News

    • The Indian Space Research Organisation (ISRO) recently launched the second development flight of the Small Satellite Launch Vehicle (SSLV).

    More about the news

    • About:
      • The Small Satellite Launch Vehicle (SSLV-D2) was launched successfully from the first launch pad at the Satish Dhawan Space Centre SHAR, Sriharikota, Andhra Pradesh. 
        • It was ISRO’s first launch of 2023.
      • It will place the Indian Space Research Organisation (ISRO) earth observation satellite EOS-07 and two co-passenger satellites Janus-1 and AzaadiSat2  in a 450-km circular orbit around the Earth. 
        •  Janus-1 and AzaadiSat2 are developed by start-ups.
      • G20 logo:
        • The satellite will also carry the G20 logo to space and the NCC song to celebrate 75 years of the organisation.


    • Janus-1 is a technology demonstrator satellite built by United States-based Antaris and its Indian partners XDLinks and Ananth Technologies.
    • It weighs only 10.2 kg, is a six-unit cube satellite with five payloads on board — two from Singapore, and one each from Kenya, Australia, and Indonesia. 
    • The entire satellite was built in 10 months, less than half the time it usually takes to manufacture satellites of this size.


    • The payloads have been built by 750 girl students from across India. 
    • The payloads contain: 
      • LoRa amateur radio, a sensor to measure radiation levels in space, and sensors to measure the health of the satellite such as temperature, reset count, and inertial data

    Significance of SSLV

    • Multiple satellites & multiple drop-offs:
      • SSLV is perfectly suited for launching multiple microsatellites at a time and supports multiple orbital drop-offs
        • SSLV is capable of launching Mini, Micro, or Nanosatellites (10 to 500 kg mass) to a 500 km planar orbit. 
    • Development of commercial Market:
      • The new vehicle was developed to capture the emerging small and micro satellite commercial market, with launches offered on demand. 
        • The launch of small satellites has until now been dependent on ‘piggy-back’ rides with big satellite launches on ISRO’s work-horse
    • Less time, manpower & cost-effective:
      • It will take only 72 hours to integrate, unlike the 70 days taken now for a launch vehicle.
      • Only six people will be required to do the job, instead of 60 people. 
        • So, the entire job will be done in a very short time and the cost will be only around Rs 30 crore.
      • It will be an on-demand vehicle.

    Previous development flight:

    • Failure:
      • The vehicle’s first development flight that took place last August after repeated delays due to the pandemic, failed to place the satellites in precise orbit.
    • Analysis:
      • A failure analysis report on why satellites were not injected in desired orbits during the August launch suggests that it was because of vibrations picked up by the accelerometers on-board, which led to the systems thinking that they were faulty.

    About Polar Satellite Launch Vehicle

    • It is the third generation launch vehicle of India.
    • It is the first Indian launch vehicle to be equipped with liquid stages.
    • After its first successful launch in October 1994, PSLV emerged as the reliable and versatile workhorse launch vehicle of India with 39 consecutively successful missions by June 2017.
    • The vehicle successfully launched two spacecraft – Chandrayaan-1 in 2008 and Mars Orbiter Spacecraft in 2013 – that later travelled to Moon and Mars respectively.
    • Difference: PSLV was developed to launch low-Earth Orbit satellites into polar and sun synchronous orbits whereas GSLV was developed to launch the heavier INSAT class of geosynchronous satellites into orbit.

    Difference between circular and elliptical orbits

    • Mostly objects such as satellites and spacecrafts are put in elliptical orbits only temporarily. 
    • They are then either pushed up to circular orbits at a greater height or the acceleration is increased until the trajectory changes from an ellipse to a hyperbola and the spacecraft escapes the gravity of the Earth in order to move further into space.
    • Satellites that orbit the Earth are mostly placed in circular orbits. 
      • One reason is that if the satellite is used for imaging the Earth, it is easier if it has a fixed distance from the Earth. 
      • If the distance keeps changing as in an elliptical orbit, keeping the cameras focussed can become complicated.

    Source: TH