India’s newly launched SSLV -D1 failed

7 mins read

First I will try to explain the Mission objectives then I will explain why this mission failed. I will request you to keep reading till the last word to get the idea.

You’re quite wondering what is SSLV. Meanwhile, you’re also appreciating India for its advancement in the field of science and technology.

So without wasting our time we move toward that what is SSLV?

SSLV stands for Small Satellite Launch Vehicle. The Small Satellite Launch Vehicle (SSLV) is a small-lift launch vehicle developed by the Indian Space Research Organisation (ISRO) with a payload capacity to deliver 500 kg (1,100 lb) to low Earth orbit (500 km (310 mi)) or 300 kg (660 lb) to Sun-synchronous orbit (500 km (310 mi)) for launching small satellites, with the capability to support multiple orbital drop-offs.] SSLV is made keeping low cost, and low turnaround time in mind with launch-on-demand flexibility under minimal infrastructure requirements.

EOS-02 and “AzaadiSAT,” an 8-kilogram CubeSat created by 750 female students from government schools in India, are manifested by SSLV-D1.

The Small Satellite Launch Vehicle (SSLV) is a new launch vehicle from ISRO that can send Mini, Micro, or Nanosatellites (10 to 500 kg in mass) into an orbit of 500 km in the upper atmosphere. All three stages of the SSLV’s three-stage design include solid propulsion. A liquid-based Velocity Trimming Module is used to propel the satellite into its intended orbit (VTM).

What is EOS-02?

EOS stands for Earth observation Satellite. Indian Earth observation satellite EOS-02, formerly known as Microsat 2A, was created by the Indian Space Research Organization as a test payload for the inaugural launch of the Small Satellite Launch Vehicle (SSLV). Based on Microsat-TD is EOS-02. The goal of EOS-02 is to develop and launch an experimental imaging satellite with a quick turnaround and demonstrate the capability of launch on demand.

Salient Features of EOS-02

  • A flexible and experimental satellite with an imaging payload is what EOS-02 is designed to be.
  • Supplying information on thermal anomalies to support applications for forestry, hydrology, agriculture, soil, coastal studies, and other geoenvironmental studies.

EOS-02 configuration

EOS-02 configuration
EOS-02 configuration
  • The structure’s framework is made of an aluminum honeycomb. A 552 mm x 600 mm x 600 mm cuboid structure is intended and qualified for a 145 kg total spacecraft mass.
  • Subsystems for the mainframe/Bus are integrated with separate payloads. The top deck has space for the entire payload.
  • The only deployable appendages are the two solar panels, each of which can produce 350 W of power.
  • The platform has a pointing precision of 0.1 and mobility of 3.5°/s.
  • In X-Band, the payload data transmission rate is 32 Mbps.

Payload Accommodation

It means that what will be the configuration of payload on the rocket. In the picture below you can
see the payload docked on SSLV-D1.

payload docked on SSLV-D1


The 8U Cubesat AzaadiSAT weighs about 8 kilograms. In honor of the nation’s 75th Independence Day, it carries 75 separate payloads that each weigh about 50 grams and conduct femto-experiments. These payloads were constructed with the assistance of 750 female students from rural areas around the nation. The “Space Kidz India” student team integrates the payloads.


The launch vehicle

SSLV-D1 Poised at FLP, SHAR (ISRO)

SSLV-D1 Poised at FLP, SHAR (ISRO)

Features of SSLV-D1

  • To save segment assembly and launch integration time, the booster motor segment has an open joint configuration.
  • Pyro systems can be started directly using a shortened Pyro circuit.
  •  Modular separation of hardware and software for quick turnaround and easy production.
  • unified configuration of the interstage joints to facilitate rapid integration and launch. Multi-Satellite Adaptor (MSA) deck for multi-satellite accommodations.
  • Low-cost, industrial COTS avionics systems have been downsized.
  • An integrated inertial navigation system for the NaviC that is affordable and has a control class MEMS sensor allows for assisted navigation throughout the flight regime. a totally indigenous digital control system with electromechanical actuators.
  • With a minimal number of ground connectors, the onboard checkout computer has a
    straightforward and quickly reconfigurable checkout system.

Flight Events

SSLV-D1 Flight Profile
SSLV-D1 Flight Profile


Failure is the road to success. I appreciate the ISRO for their courage to facet the critics. These satellites are manufactured by students. We have to appreciate them too. Unfortunately at the terminal stage due to some data loss, the SSLV-D1 deployed the satellite in orbit which is not desired. This is what the ISRO chairman said:

Issuing a statement on the SSLV-D1/EOS-02 mission update, ISRO said, “All stages performed normally. Both satellites were injected. But the orbit achieved was less than expected which makes it unstable.”

Reason of Failure

It failed due to the loss of Data from the sensor. SSLV-D1 placed the satellites into 356 km x 76 km elliptical orbit instead of a 356 km circular orbit. Satellites are no longer usable. The issue is reasonably identified. Failure of a logic to identify a sensor failure and go for a salvage action-Said the chairman of ISRO.

We must appreciate them. At least they have tried are we trying? An open question for SUPARCO and the whole of Pakistan? Alarming Situation for Pakistan.

Huzaifa Mustafa

The writer is a 19-year-old Mechanical Engineering Student having a keen interest in Investigative Journalism.

Twitter: @huzaifamustafa_


  1. We as students are caged in getting CGPA and have no practical experience of what we are doing. On the other side, India is developing day by day.
    May Pakistan rise some day.

    • Sorry to burst ur bubble but we r not developing day by day. How Is sending a satellite to space considered ‘development’??
      India is still one of the POOREST countries on earth. Why do pakistanis forget this fact?? An average pakistani is much better than an average indian.

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