Science and Technology – developments and their applications and effects in everyday life Achievements of Indians in science & technology; indigenization of technology and developing new technology.
India’s PSLV C35 launched 8 satellites in two different orbits. It is first time such feature has been achieved by ISRO. Till now, PSLV has launched 20 satellites in one go, but they were all in same orbit.
It started with PSLV C-29 and C-34 also experimented upon, but it was C-35 that achieved this complex feat. It is called a multiple burn technology where the fourth stage engine is switched off and re-ignited. This was done twice. It is really complex task in the cold and low gravity environment- between the two switch offs to cool the engine and when the engine restarts.
Need to switch on and off twice
This rocket has to manoeuvre and move between two poles so that it can make shift from the orbit, either from higher to lower or lower to higher. In this case, the first satellite, the SCATSAT-1 that was launched just after 17 minutes and into polar sunsynchronus orbit which is at an altitude of 750 km. After that, remaining 7 satellites were put into a lower orbit that has an altitude of about 689 km. This was done due to multiple burn technology.
The Scatterometer Satellite 1 – or SCATSAT-1 – spacecraft is designed to serve as a substitute to help in measuring ocean winds following the failure of the OSCAT instrument aboard the OceanSat-2 satellite in February 2014.
OceanSat-2 was India’s first satellite to carry a scatterometer for sea wind research. It was launched in 2009. But, in 2014 when the travelling wave tube amplifier (TWTA) in the OSCAT instrument malfunctioned, it became unusable.
Thus, SCATSAT 1 is basically a weather watching satellite which will help in forecasting cyclones and also carry out deep study on the wind movement. Other satellites are:
ALSAT-1B earth observation satellite
ALSAT-2B remote sensing satellite
ALSAT-1N technology demonstrator
Pathfinder 1 satellite- commercial high resolution imagery satellite
Technology demonstrator nano satellite- Experimentation with regards to space debris etc.
Pratham- IIT Bombay- to count number of electrons in space.
PISAT- Bengaluru- for remote sensing studies
PSLV has a very limited range because it cannot carry directly to the GTO though it has been done in case of Chandrayan and Mangalyan.
Even the SCATSAT launch was by a more powerful version than the other versions.
There are three PSLV version
Standard version- have booster motors (9 tons heavy propellant)
Core alone- doesn’t have the booster motors
Extra-large- have booster motors (12 tons heavy propellant)
Now the next target is GSLV. Recently, there was a launch of INSAT 3DR which was launched by GSLV MK-II. This was the first operational launch of the GSLV and now they are looking forward to GSLV Mk-III as with that only very heavy satellites of the INSAT class can be launched. (4 tons or more).
India is falling short of transponders where it needs 500 transponders but has less than 300. Thus, there is a big need of transponders to fulfil all the telecommunication and other needs.
Transponders are communication satellites’ channels which are used for home to home, DTH and for other communication purposes. With this, India can also fully prepare GSLV Mk-II so that India can launch its own INSAT class satellites.
At present, India has to go to other countries for their launch. With foreign launches, the problem is that they have their own schedules. So when India wants to get its satellite launched, there is a queue. So, India may not be able to launch a satellite when it needs. Hence, development of that capability of 4 ton INSAT class satellite is very important.
ISRO has said that it may launch INSAT from India by the year end, but it might take one or two years to succeed completely.
ISRO’s uniqueness and future
ISRO has done many things in innovative ways. INSAT 1 series, it was a 3-in-1 satellite. It combined the weather watching, communication operation in one satellite. Hence, building such satellites is less costly.
SACTSAT also has something unique which was built in record time (less than year) and record cost. It was built using some spare parts which were left over from other missions and so the cost is 40% of would it could have been. With this satellite, it has been shown that innovativeness helps in cost cutting as well as in an indigenous manner which has been motto of ISRO.
The multiple burn technology has been achieved by very few nations. Most of the countries are launching multiple satellites on only one orbit. But in multiple orbits, it gives an edge to ISRO and it is the reason why other countries such as USA are coming to India for launching their satellites.
This was 32nd satellite launched by ISRO in 2016, including the 20 satellites launched by CARTOSAT 2C. Many countries are coming to India, especially to launch small satellites.
In future, ISRO can develop into a multibillion dollar satellite launching industry.
Connecting the dots:
ISRO has been time and again proving its mettle in India’s satellite development programme. What are the recent key achievements by ISRO and future projects?